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Carbon fiber reinforced polymer (CFRP) has excellent mechanical properties and has been widely used in aviation, aerospace, and other fields. Due to the anisotropy of CFRP, it is easy to cause cutter wear during the machining process, resulting in machining defects such as burrs, tearing, and delamination. In this paper, a comparative experimental study on the inclined angle milling of CFRP with flat end milling cutter and circular arc milling cutter is carried out. The axial force, cutter wear, the quality of hole entrance and exit, and the hole wall micro-morphology of the two cutters under the inclined angle milling method were analyzed. The results show that compared with the tip area of the flat end milling cutter, the arc transition area of the circular arc milling cutter increases the contact area with the workpiece and reduces the milling axial force. The cutter wear of circular arc milling cutter is mainly concentrated in the arc transition area, and the wear gradually diffuses to the nearby cutting edge. However, the wear of flat end mill cutter is mainly concentrated in the cutter tip area. As the number of holes increases, the cutter tip gradually becomes blunt, and the wear area further expands to the area near the cutter tip. With the increase of cutter wear, the entrance defects of the processing hole of the two cutters are less, and the exit of the hole of the circular arc milling cutter has defects such as tearing and burrs. In addition, there are defects such as exposed fiber and cavities on the surface of the hole wall. Compared with the circular arc milling cutter, the flat end milling cutter has more defects at the exit of the hole. At the same time, there are many surface cavities, pits, and fiber pull-out phenomena on the surface of the hole wall. [ABSTRACT FROM AUTHOR]

The modern manufacturing industry is inextricably linked to the development of advanced manufacturing technology. Especially in the energy chemical industry, aerospace, and other important fields, cutting processing is the production of a variety of equipment key components of the processing mode, and the tools as an important part of cutting processing; cutting tool performance put forward higher requirements. In order to improve the cutting performance of tools, the combination of surface microstructure technology and surface coating technology to modify the surface of the tool has great prospects for development. It has been shown that the embedding of both microstructures and coatings on the tool surface has better cutting performance, to better show the current research status of micro-structured composite-coated tools. Firstly, the fabrication method of micro-structured composite-coated tools is introduced. Secondly, it summarizes the cutting performance of micro-structured composite-coated tool from six aspects: wear resistance, cutting force, friction coefficient of tool-chip contact interface, cutting temperature, tool life, and chip formation. Then, the effect of micro-structured composite-coated tool on surface quality was analyzed and summarized. Finally, the current research status of micro-structured composite-coated tool is summarized, proposed the current problems, and possible future research directions. [ABSTRACT FROM AUTHOR]

In order to improve the performance of high-pressure abrasive water jet cutting extremely hard rock, research on the cutting effect and mechanism of abrasive water jet was carried out. The research focused on cutting depth, and one-factor tests were devised to cut hard rock using key parameters of high-pressure abrasive water jets. The cutting performance of the process parameters was assessed using both the cutability index and the energy-consumption index. The mechanism of abrasive water jet cutting hard rocks was examined using a stereomicroscope. The governing relationships of key parameters influencing the effectiveness of abrasive waterjet in breaking extremely hard rocks were investigated. The results indicate a linear correlation between the cutting depth of the abrasive water jet and pump pressure. Additionally, there is a power function relationship with traverse speed and target distance, a quadratic function relationship with abrasive flow, an exponential function relationship with nozzle diameter, and a logarithmic function relationship with cutting times. Under high traverse speed conditions, the removal mechanism of the abrasive water jet on hard rock involves brittle fracture and plastic shear, while on extremely hard rock, it encompasses plastic shear and a minimal amount of brittle fracture. These research findings can serve as a valuable reference for choosing construction parameters for abrasive water jet-assisted TBM cutting of hard rock. [ABSTRACT FROM AUTHOR]

Abstract The non-conventional manufacturing technologies are notorious when it comes to productivity and processing time in production-related industries. However, the aerospace and other high-end sectors enjoy another quality matrix of these processes and compromise on the processing time. For instance, the machinability of hard-to-cut materials such as Ti6Al4V aerospace alloy for micro-impressions is challenging and commonly carried out through non-conventional processes. Among these processes, the electric discharge machining (EDM) is famous for machining Ti6Al4V. In the current study, the EDM process is enhanced through modified dielectrics such as kerosene with non-ionic liquids (span 20, 60, and 80) and cryogenically treated tool electrodes (aluminum and graphite), and is compared to the conventional kerosene-based process. A three-phase experimental campaign is deployed to explore parametric effects including modified dielectric conditions (non-ionic liquid type and concentration), tool material, and machine parameter pulse ON:OFF time. A total of 60 experiments (54 modified dielectrics and 6 as baseline) were performed to explore process physics. The statistical analyses show that the unmodified process (kerosene dielectric-based) results in the least favorable results 0.58 mm3/min against cryo-graphite and 1.2 mm3/min against cryo-aluminum electrodes. However, the modified dielectrics outperform and improve process dynamics by altering dielectric conditions through hydrophilic-lipophilic balance. Surface morphological analysis shows significantly shallow craters on the machined surface showing evidence of effective flushing through a modified dielectric (S-20) as compared to a kerosene-based dielectric. A thorough microscopical, statistical, and scanning electron-based analysis is carried out to explain the process and correlate significant improvements.

In this study, TiC0.5N0.5–60 wt% W and TiC0.5N0.5–70 wt% W cermet cutting tool specimens consisting of Ti(C, N) core, W-rich Ti(C, N) rim, and W-based alloy phases with much higher strengths than conventional heat-resistant tool materials at temperatures above 1673 K were fabricated by spark plasma sintering, electric discharging, and polishing. The cutting performance characteristics of the cermet cutting tool specimens were then examined and compared with those of commercially available NX2525, JX1, and HTi10 cutting tool specimens when cutting S32750 super-duplex stainless steel round bars under dry condition at a cutting speed of 800 m/min. The NX2525, JX1, and HTi10 specimens were TiC–Ni-based cermet containing Mo, Nb, and Co, WC–Al2O3-based composites, and WC–Co cemented carbide, respectively. The TiC0.5N0.5–70 wt% W and TiC0.5N0.5–60 wt% W cermet cutting tool specimens exhibited the first and second longest lifetimes among all the noncoated cutting tool specimens. The lifetime of the TiC0.5N0.5–70 wt% W cermet cutting tool specimen was extended by coating it with TiAlN film by physical vapor deposition. In contrast, the TiC0.5N0.5–60 wt% W and TiC0.5N0.5–70 wt% W cermet specimens exhibited compressive strengths much higher than those of the NX2525, JX1, and HTi10 specimens at 1973 K, whereas all the specimens exhibited similar compressive strengths at room temperature.

Ti6Al4V, as an excellent high-temperature alloy, finds widespread application in key components within industries such as aerospace, automotive, and others. However, due to its high hardness and low thermal conductivity, conventional turning of Ti6Al4V often leads to significant cutting forces and elevated cutting temperatures. Consequently, this imposes higher performance requirements on cutting tools. In dry cutting or with a cooling strategy, micro-texture tools exhibit better cutting performance than conventional tools. This paper investigates the performance of the edge margin complex micro-texture tool and its influence on the machined surface during cutting Ti6Al4V. Through experiments and numerical simulations of the Ti6Al4V cutting process, the cutting performance of four different types of tools is studied. Simulation models of different cutting tools are established, and changes in cutting force, thrust force, cutting temperature, and Von Mises Stress are compared. The results indicate that, compared with the round edge tool, the maximum temperature decreases by up to 16.7%, and the maximum Von Mises Stress decreases by up to 69.6% with the edge margin complex rectangular micro-texture cutting tool. Moreover, the occurrences of self-excited vibration with the other three types of tools decrease by 4.3% to 48.6%. These findings contribute to improving surface quality and prolonging the life of cutting tools when cutting Ti6Al4V with the edge margin complex rectangular micro-texture cutting tool. [ABSTRACT FROM AUTHOR]

Copyright of China Mining Magazine is the property of China Mining Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A suitable texture location is a significant factor in avoiding derivative cutting and improving friction conditions. This paper aims to explore the impact of texture in the sticking and sliding friction regions on cutting performance. The chip distribution model was established and validated to assess the distribution of friction regions. Turning experiments with and without MoS2 solid lubricants were conducted on AISI 304 using textured tools with various texture locations determined by the chip distribution model. The results derived from the prediction model aligned favorably with the experimental results, and the location near the boundary of the sticking and sliding friction regions was the suitable initial location of tool surface textures. Under dry cutting conditions, the texture at the termination of the sticking region increased the cutting force and temperature by only 0.5% and 4.8%, while the presence of MoS2 caused a decrease in cutting force and temperature by 2.9% and 3.5%, respectively. [ABSTRACT FROM AUTHOR]

Ball-end milling cutters are commonly used in the finishing processes of curved-side milling for titanium alloys; however, several issues arise during machining, such as poor cutting conditions at the bottom of the end teeth, low cutting speeds, and limited chip space. Given the above issues, the research on the design and manufacture of conical arc side-edge milling cutter for titanium alloy processing was carried out in this paper; the mathematical model of the vital structure of conical arc side-edge milling cutter was established; the grinding trajectory equations of tool front and flank were deduced; the tool-workpiece kinematics of ultrasonic vibration applied to conical arc side edge was studied; and the comparative experimental study of the conical arc side-edge milling cutter cutting titanium alloy with and without ultrasonic vibration was carried out. The experiment results indicate that in comparison to conventional milling techniques, ultrasonic vibration cutting significantly decreases cutting force, plastic deformation of the chip, and wear rate of the flank face. The tool wear band is both longer and more uniform, bonding phenomena in titanium alloys are distinctly reduced, and tool performance is improved. [ABSTRACT FROM AUTHOR]

Ultrafine tungsten carbide (WC)–cobalt (Co) and WC–(Ti,W)C–Co end mills were produced via spark plasma sintering. The wear mechanism of these end mills during machining of AISI H13 steel was investigated. WC–Co exhibits good mechanical properties (HV30: 2110 kg/mm2, KIC: 10.4 MPa/m1/2, TRS: 1990 MPa). Although the high hardness of WC–Co makes it show excellent resistance to abrasive wear, it suffers from a significant adhesion problem. As the cutting temperature increases, the oxidation of the WC–Co causes damage to the microstructure of tool materials, which deteriorates the grain boundary strength and promotes adhesive wear. This phenomenon causes large areas of tool materials to chip off and eventually results in cutting‐edge breakage. The high brittleness of (Ti,W)C causes cracks to propagate at low‐stress levels, reducing the mechanical properties of WC–(Ti,W)C–Co (KIC: 8.8 MPa/m1/2, TRS: 1090 MPa). However, (Ti,W)C addition enhances the resistance to oxidation and workpiece adhesion, which reduces the tool material loss caused by adhesive wear. The tool life of WC–(Ti,W)C–Co is three times longer than that of WC–Co in milling of AISI H13 at the same cutting speed. The key to maximizing the mechanical properties of ultrafine cemented carbide tools when machining AISI H13 is the modification of anti‐adhesive wear of surface. [ABSTRACT FROM AUTHOR]

Artificial fractures on the tunnel face can promote tunnel boring machine (TBM) performance in the intact rock mass with high rock strength. High-pressure water jet (HPWJ) is a feasible choice to pre-cut the kerfs on the tunnel face to assist in TBM tunnelling. To study the effects of different layouts of the TBM cutter and HPWJ on the cutting performance and the corresponding rock breakage mechanism, a series of full-scale linear rock cutting tests were conducted. The analysis included the TBM cutter force, cutter vibration, rock muck and rock-breaking specific energy. According to the results, two HPWJ-assisted cutting layouts are recommended. One is arranging the HPWJ nozzle ahead of the cutter, making the cutter cut along the kerf. The rock damage zone after the cutter penetration was rather limited since the kerf beneath the cutter prevented the formation of the pressurized crushed zone and the generation of the lateral cracks that occurred in the intact rock. The lowest cutter force and vibration were obtained with the shallow kerf depth compared with the other layouts. Creating kerfs with a depth slightly lower than the cutter penetration is suggested to vastly save energy. Another recommended layout is arranging the nozzles between all the cutter trajectories, making the cutter cut along the middle line of two kerfs. The breakage mechanism turned to the interaction between the cutter and adjacent kerfs, macro-cracks generated from the cutter tip could propagate to the bottom of kerfs on both sides. The cutter force and the magnitude of oscillations decreased with the increasing kerf depth. The largest rock-breaking volume and lowest specific energy were obtained among all the tests. The suggested kerf depth is about twice the cutter penetration, above which the specific energy would not significantly decrease. The study is helpful to the cutterhead design of the TBM assisted with HPWJ and the promotion of TBM performance. Highlights: Linear cutting tests using the HPWJ and full scale TBM cutter were successively performed with various layouts. The analysis of cutter performance comprises force, induced vibration, specific energy and mucks characteristics, validating the feasibility of the assistance of HPWJ. Arranging HPWJ nozzles on and between the cutter trajectories were recommended to drastically reduce the cutter force and specific energy, respectively [ABSTRACT FROM AUTHOR]

Although minimum quantity lubrication (MQL) machining offers excellent economic and environmental benefits, its application in actual production has been extremely restricted due to the lack of understanding of the oil mist penetration and lubrication mechanism. To reveal the oil mist penetration mechanism and process characteristics of the MQL milling process, the response surface methodology (RSM) was adopted to investigate the interaction of factors on the MQL cutting performance, optimize the process parameters, and establish the predictive models. Furthermore, the CFD simulation of the fluid field characteristics and negative pressure oil mist penetration tests were carried out to reveal the mechanism of oil mist penetration. Experimental results show that the interaction of factors has a different effect on response variables due to the various penetration capabilities, and compared with dry cutting, MQL reduced surface roughness by 34.58%, cutting temperature by 31.77%, cutting force by 21.26%, and tool wear by 60.34%. The results of CFD simulation and penetration experiments indicate that the penetration rate of oil mist is related to many factors, including the size and survival time of the capillary and the diameter and number of droplets. The findings of this work can provide valuable guidance for industry production and future investigations. [ABSTRACT FROM AUTHOR]

In order to explore the influence of textured sawteeth on saw blade cutting and wear performance, linear micro textures perpendicular to the chip flow direction were fabricated on the rake face, main flank face, and secondary flank face by laser machining, respectively. The cutting tests were carried out on sawing platform with different cutting speeds under lubrication conditions. The cutting forces, noise, temperatures, machined surface quality, and sawtooth wear were investigated. The results indicated that textures fabricated on the secondary flank face can effectively reduce friction with the machined surface and improve the surface quality, and the roughness Ra decreased about 2.5 ~ 12.5% compared with traditional saw blade. The improvement of saw blade cutting performance by machining micro textures on the main flank face was greater than the textures fabricated on the rake face. Due to the synergistic action of textures on different cutting faces, the cutting force, noise, and temperature of saw blades with textures prepared on all cutting surfaces were the lowest. The main wear forms of sawteeth were tip wear, surface adhesion wear, and oxidation wear. Although the derivative cutting phenomenon occurred, the micro textures were not completely filled, which signified that the micro textures still played the role of stored cutting fluids, reduced contact area, and formed lubrication film. [ABSTRACT FROM AUTHOR]

Carbide tools are extensively used in the automotive, aerospace, and marine industries. However, an unsuitable tool-edge treatment can affect the cutting performance of carbide tools. In the tool-cutting process, the cutting edge radius is one of the major factors that affect the cutting force, temperature, and quality. In this study, a cutting simulation model of carbide inserts was used to analyze the effect of the cutting edge radius on the cutting performance. The cutting edge radii of the inserts were prepared using shear-thickening polishing methods, followed by cutting experiments. The accuracy of the cutting simulation model was verified through cutting experiments. The simulation results showed that under low-speed cutting conditions, the cutting force and temperature tended to increase with an increase in the cutting edge radius, and the cutting temperature was less affected by the cutting edge radius. The results of the cutting force and cutting temperature obtained from the experiment and simulation were consistent; therefore, the cutting simulation model was verified to be reliable. The results indicate that modeling cutting simulation is a promising research method for predicting the cutting performance of tools. [ABSTRACT FROM AUTHOR]

Cobalt-based superalloys are widely used in hot-end components of gas turbines due to their excellent elevated temperature mechanical properties. At present, cobalt-based superalloys are usually machined under cutting fluid, which will seriously pollute the environment and harm human health. Cryogenic cutting technology uses liquid nitrogen, supercritical carbon dioxide, etc. as the cooling medium, which has the advantages of environmental protection and energy conservation. In this paper, the cryogenic mechanical properties of cobalt-based superalloy GH605 were investigated, and then the cutting experiments were conducted under three different cooling and lubrication methods (flood condition, cryogenic minimum quantity lubrication, and liquid nitrogen) to investigate the cryogenic machinability and machining sustainability of GH605. The results show that cryogenic temperature can reduce the plasticity of GH605 but has little effect on the compressive yield strength and compressive strength. Compared with the cutting fluid, the cutting force of liquid nitrogen is reduced by up to 72.2%, the cutting-specific energy is reduced by about 83.9%, and the concentration of particulate matter such as PM2.5 generated during the processing can be decreased by more than 60%. The surface finish and consistency of cryogenic minimum quantity lubrication are better; the surface roughness is reduced by 0.4 ~ 20.4% at different cutting speeds. When the feed speed is greater than 0.10 mm/r, the work hardening degree decreases by 0.8 ~ 19.7%. Under the two cooling strategies, the chip surface is smooth and flat, chip breaking property is improved, but the machining noise is more than 100 dB. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In line with engineering research focusing on metal tools, techniques to record the attribute of 'edge sharpness' on stone tools can include both mechanical and micro-geometric approaches. Mechanically-defined sharpness techniques used in lithic studies are now well established and align with engineering research. The single micro-geometrically-defined technique—tip curvature—is novel relative to approaches used elsewhere, and has not explicitly been tested for its ability to describe the attribute of sharpness. Here, using experimental flakes produced on basalt, chert, and quartzite sourced at Olduvai Gorge (Tanzania), we investigate the relationship between tip curvature and the force and work required to initiate a cut. We do this using controlled cutting tests and analysis of high-resolution microCT scans. Results indicate cutting force and work to display significant dependent relationships with tip curvature, suggesting the latter to be an appropriate metric to record the sharpness of lithic tools. Differences in relationship strength were observed dependent on the measurement scales and edge distances used. Tip curvature is also demonstrated to distinguish between the sharpness of different raw materials. Our data also indicate the predictive relationship between tip curvature and cutting force/work to be one of the strongest yet identified between a stone tool morphological attribute and its cutting performance. Together, this study demonstrates tip curvature to be an appropriate attribute for describing the sharpness of a stone tool's working edge in diverse raw material scenarios, and that it can be highly predictive of a stone tool's functional performance. [ABSTRACT FROM AUTHOR]

Copyright of Automobile Technology & Material is the property of Automobile Technology & Material Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An increasing number of cutting tools with different geometric shapes are needed owing to the increasing complexity of the workpiece surfaces in aerospace and automotive molding. A new kind of milling cutter is designed, which is named as revolving lemniscate milling cutter (RLMC for short). The parametric mathematical models of RLMC are proposed. Mathematical models of cutting edge curves are proposed to provide the theoretical basis for RLMC precision manufacturing. Equivalent helix angle, curvature radius of tool rotation surface, effective cutting linear velocity, and scallop height are studied. Corresponding numerical simulation results are also provided as graphical representations. Three RLMC with different tool parameters are manufactured, and contrast experiments are conducted to prove that using RLMC in end milling can achieve better machining quality. The parametric design and application research provide a new method and theoretical basis for other new types of milling cutters. [ABSTRACT FROM AUTHOR]

The primary cause of tool failure in rough cutting is the severe tool-chip friction brought on by chip adhesion and abrasive wear. To address the problem, the influence of combinations of micro-textures and AlCrN coating, and the sequence of their combinations on tool surface characteristics and cutting performance in dry cutting AISI 304 were investigated. The results of wettability and indentation tests indicate the micro-textures reduce the contact angle of the tool surface (by 13.26%) and increase the contact area between micro-textures and the coating, resulting in a better adhesive strength (grade HF3) for the first micro-textured and then AlCrN-coated tool (TCT). The results of cutting experiments demonstrate that the TCT's cutting performance is improved as the cutting speed increases between 50 and 141 m/min, with the highest reductions in main cutting force and radial cutting force reaching 27% and 38% at 141 m/min. The TCT's micro-textures reduce tool-chip contact area, while the intact AlCrN coating film decreases chip adhesion and improves the wear resistance of cutting tools. This study is expected to be applied to further improve the tool performance under dry and rough cutting conditions. [ABSTRACT FROM AUTHOR]

This research investigated the cutting performance of three different types of Si3N4‐based ceramic tools (Si3N4, Si3N4–SiCw, and Si3N4–SiCw–HfB2) with distinct mechanical properties during turning of ductile cast iron. Si3N4 ceramic tool, characterized by high hardness and low toughness, showed minor micro‐chipping and the highest average flank wear rate during the initial wear stage, leading to a short cutting life of 1679 m. Si3N4–SiCw ceramic tool, with low hardness and high toughness, exhibited the highest average flank wear rate during the middle and final wear stages, resulting a short cutting life (1602 m). In contrast, the Si3N4–SiCw–HfB2 ceramic tool, featuring high hardness and high toughness, demonstrated the lower average flank wear rate during all the wear stages, leading to a longest cutting life (2636 m). The results indicated that the average flank wear rate during the initial wear stage was mainly influenced by toughness, while during the middle and final wear stages, the average flank wear rate was primarily dependent on hardness. [ABSTRACT FROM AUTHOR]

Adhesive wear is the primary failure form of coated tools in zirconium-based bulk metallic glasses (Zr-based BMGs) machining. This work investigated the adhesion formation and failure of TiN/Al2O3/Ti(C,N), Al2O3/Ti(C,N), and TiAlN-coated tools when machining Zr41.2Ti13.8Cu10Ni12.5Be22.5 BMG. Characterization of tool-chip interfacial material responses revealed the mechanism of adhesive wear. The relationship between the wear resistance and micro-mechanical properties of coatings was established. The cutting performance of coated tools is also discussed. According to the results, the adhesive wear of coated tools results because the temperature at the tool-chip interface is above the glass transition temperature, reducing the viscosity of chips. Low-viscosity chips were welded to the tool surface under high pressure. Subsequently, high interfacial friction tore the adhesive interface, causing coatings to peel off layer by layer. The exposed tool substrate also generated secondary adhesion, which triggered the diffusion of tungsten and cobalt atoms towards the chip. This was accompanied by redox reactions that exacerbated tool failure. The wear resistance of coatings depended on the elastic modulus (E) and the ratio of nano hardness to elastic modulus (H/E). The TiAlN coating had a lower E of ∼410 GPa and higher H/E of 0.064, and it exhibited better wear resistance than the TiN/Al2O3/Ti(C,N) (E ∼ 436 GPa, H/E = 0.051) and Al2O3/Ti(C,N) (E ∼ 469 GPa, H/E = 0.061) coatings. The lifespan of the TiAlN-coated tool was more than three times longer that of the other two, and the obtained machined surface roughness was less than half that of the others.

ABSTRACTTo improve the cutting performance and prolong the service life of a carbide-coated tool in the process of ductile iron machining, an electromagnetic coupling treatment (EMCT) was carried out. The cutting experiments show that the cutting force and cutting temperature are reduced after EMCT, and the roughness of the machined surface is reduced. It is found that after EMCT with optimal parameters the dislocation density, microscopic strain, microhardness and bonding strength of an alumina coating increase by 109.2%, 28.2%, 28.3% and 26.6%, respectively. Using the actual machining of a differential housing to verify the tool life, it is found that after EMCT, a single tool can process 18.4 more workpieces or in other words, the tool life increased by 44%. EMCT can promote element diffusion, optimize coating properties and have great potential in coating tool life extension.

There are inequable force-induced deformation, obvious cutting vibration problems during side milling of low-rigidity frame and beam parts, resulting in unsatisfactory dimensional accuracy and surface quality. Most of these parts are side-milled by end mill, which currently in use do not take into account the workpiece stiffness imparity. Therefore, the concept of gradient helix edge (GHE) is proposed in this research, and its advantages are analyzed. The general mathematical model is given. Furthermore, the parabola is taken as an example for the GHE space equation derived, of which accuracy is verified by numerical simulation. Finally, the comparison experiment with the invariant helix edge end mill was completed. The results showed that the milling force perpendicular to the milling surface of the GHE end mill was smaller and with less fluctuation, which could obtain less force-induced deformation theoretically. The milling process was smoother, and better surface quality was obtained. The excellent performance of the GHE end mill was further verified by milling different features. [ABSTRACT FROM AUTHOR]

Titanium alloys have been widely used as an aerospace material owing to their excellent mechanical properties. However, ordinary tools can suffer from severe chip adhesion and surface abrasion when turning titanium alloys. To address these problems, micro-textured cutting tools have become a topic of significant research. Here, to improve the preparation process of textured tools, a novel tool prepared by an integrated molding process was proposed. The performance of this novel textured tool in terms of turning Ti-6Al-4 V was investigated under dry condition and minimum quantity lubrication (MQL). Textured surfaces with four types of patterns and dimensions were used in the turning experiment to draw a comparison with traditional cutting tools. The results showed that the textured surface exhibited a uniform and smooth appearance with no obvious defects, indicating that the integrity of the textured surface was maintained. The combination of a micro-textured surface and the MQL method decreased the process temperature and cutting force. The narrower parallel type of textured tool exhibited the best performance. The process temperature reduced to 124 °C for the narrower parallel textured tool under MQL, decreasing by ~ 14.5% compared with the traditional tool; the lowest main cutting force and feed force were obtained for the narrower parallel textured tool, approximately 212 N and 171 N, respectively. Significant improvements in chip adhesion and tool wear were observed for the textured tool. Application of textured surface and MQL method are both decreased the adhesive scale layer area on the rake face of tools compared with ordinary tools. [ABSTRACT FROM AUTHOR]

To improve the cutting performance and prolong the service life of a carbide-coated tool in the process of ductile iron machining, an electromagnetic coupling treatment (EMCT) was carried out. The cutting experiments show that the cutting force and cutting temperature are reduced after EMCT, and the roughness of the machined surface is reduced. It is found that after EMCT with optimal parameters the dislocation density, microscopic strain, microhardness and bonding strength of an alumina coating increase by 109.2%, 28.2%, 28.3% and 26.6%, respectively. Using the actual machining of a differential housing to verify the tool life, it is found that after EMCT, a single tool can process 18.4 more workpieces or in other words, the tool life increased by 44%. EMCT can promote element diffusion, optimize coating properties and have great potential in coating tool life extension. [ABSTRACT FROM AUTHOR]

With the transformation and upgrading of the manufacturing industry and the advent of the industrial revolution, the complexity of part structures and the variety of materials have increased. The demand for cutting tool performance is becoming increasingly diverse, posing numerous challenges to the design and development of tools. By studying natural cutting phenomena, scholars have discovered that biological structures such as teeth and claws possess unique characteristics. The design and development of tools based on the imitation of these biological structures have become a new research direction. To address the high energy consumption and reduce cutting resistance in the cutting process, limpet teeth were prepared, and their geometric features were extracted. The structural features of limpet teeth were applied to the design of tool structures, and five bionic tools were designed and fabricated. Taking cutting force as the performance indicator, the cutting performance of the bionic tools was investigated by comparing them with conventional tools. The analysis of cutting forces found that effortless tool exhibited a significant force-saving effect, with a reduction in cutting force by 16.2%. Through a single-factor experiment, the influence of cutting parameters on the effortless tool was explored. The results showed that limpet bionic cutting tools with appropriate size parameters exhibited a significant force-saving effect, improving tool cutting performance. [ABSTRACT FROM AUTHOR]

Cutting rate in diamond wire method is one of the most important criteria in evaluation process of this method. In this research, using numerical modeling and PFC3D software, the effect of controllable parameters on the cutting rate have been investigated, the optimal values of these parameters have been determined, and finally an empirical relationship between these parameters and the cutting rate of diamond wire has been developed. These parameters include the diamond wire peripheral speed, number of beads per unit length of the wire, cutting machine pullback amperage and beads diameter. Numerical simulation and its validation are based on experiments performed on a granite stone sample. Numerical modeling results show that the wire peripheral speed and pullback amperage are directly related to the cutting rate. Optimal values for these parameters are the highest possible value. In other words, by technology advancement and ability to increase values of these parameters in wire cutting machines, higher cutting rates can be achieved. Evaluation of the number of beads per unit length of wire shows that by increasing it to 36 beads, the cutting rate increases, but with further increasing, cutting rate remains almost constant. Therefore, 36 beads per length unit of wire is the optimal value. Evaluation of the effect of the bead diameter on the cutting rate shows that the maximum cutting rate occurs when the bead diameter is equal to 1 cm. By further increasing of this parameter, cutting rate decreases. Therefore, optimal value of bead diameter is 1 cm. By comparing the effects of the mentioned parameters on the cutting rate, machine pullback amperage can be expressed as the most effective parameter. Finally, using multivariate regression, an experimental relation between the cutting rate and the mentioned parameters with a correlation coefficient of 0.98 has been achieved. This relation can be used to predict and improve the performance of diamond wire saw in granite stones' cutting. Highlights: The diamond wire cutting process is modeled with the aim of investigating and improving of its performance using PFC3D software. TBy adjusting and properly selecting each of controllable parameters, an appropriate economic diamond wire saw machine with low energy consumption and high production rate can be achieved. For granitic rock, the optimal values for the wire peripheral speed and pullback amperage are the highest possible value, the optimal number of beads per length unit of wire is 36 and the optimal bead diameter is one centimeter. The machine pullback amperage can be expressed as the most effective parameter on the cutting rate. The empirical equation between the cutting rate and four controllable parameters is presented that it is significant in terms of the multiplicity of parameters involved in optimization. [ABSTRACT FROM AUTHOR]

Machine tools are required to be able to produce workpieces according to the desired technical requirements. The goal of machining is to achieve a high production volume of good quality with maximum tool life, short production time, and low cost. The surface properties obtained as a result of the changing and developing technology in cutting processes, the introduction to manufacturing, and especially the post-processing processes are of great importance. While the time obtained as a result of fast cuts has economic value, high-quality surface obtaining provides cost savings by minimizing the subsequent machining operations. Within the scope of the study, Ø120 mm ST-52 and Ø120 mm AISI 4140 materials have been cut with smart and automatic cutting modes by our domestic band saw machine. As a result of the cuts, the roughness values and curvatures of the samples have been checked with the surface roughness device and surface gauge. While the surface roughness after cutting was 4.45 µm with the automatic cutting mode, this value decreased by 16% to 3.71 µm with the smart cutting mode. [ABSTRACT FROM AUTHOR]

Monolayer and multilayer diamond films are deposited on WC‐Co cemented carbide by hot‐filament chemical vapor deposition. The growth characteristics of diamond coatings are analyzed. Cutting performance characteristics such as tool life and the stability of machining process in the machining of presintered ZrO2 are compared based on the variation of cutting speed and resultant cutting force, and workpiece surface roughness. For the monolayer diamond coatings, as the concentration of CH4 increases from 1% to 5%, the diamond crystal is transformed from micron columnar crystal to nanocluster crystal. The multilayer diamond coatings combine the advantages of micron‐ and nanocrystalline structures. The multilayer diamond‐coated tool exhibits longer service life and better machining quality. Because of the appearance of the brittle–plastic conversion mechanism, the surface integrity of ZrO2 processed by multilayer diamond‐coated tool is relatively high. As for the uncoated tool, the workpiece is mainly machined by brittle spalling. The interfacial stratified fracture system between the interlayers is proposed to be the toughening mechanism of the multilayer structure. [ABSTRACT FROM AUTHOR]

Large-scale sputter-deposition of hard protective coatings has not been prevalent as the large dimensions of the industrial targets posed an enormous technological challenge: only relatively low power (and plasma) densities could be achieved, resulting ultimately in poor performance of such coatings. Here, we introduce a novel sputtering technology allowing to reach high power densities for industrial tubular targets. This is realised on the principle of a longitudinal movement of a reduced-size magnetron inside the target. In doing so, peak power densities of 840 W/cm2 have been achieved for the overall power of 25 kW and the target dimensions of Ø110 × 510 mm. To demonstrate the effectiveness of the solution, we produced a series of cubic (Al,Cr)N coatings by sputtering an Al60Cr40 target. Most of the coatings have a stoichiometric composition, smooth surface and a moderate amount of growth defects. Significant improvements through recipe optimisation could be achieved resulting in mechanical properties (hardness, fracture toughness, wear resistance) being equal to and even exceeding those of the benchmark coatings produced by means of conventional sputtering and cathodic arc evaporation. Our results open up great potential of this novel sputtering technique for the coating industry.

Although significant increase in mechanical properties has been achieved in α-SiAlON ceramics by introducing self-toughening bimodal microstructure, the bimodal microstructure may not always result in better cutting performance of α-SiAlON tool inserts. Herein Dy-α-SiAlON ceramics were prepared by hot-pressing at 1900°C under 30MPa. Diameter and aspect ratio of the large elongated α-SiAlON grains pivotal to formation of bimodal microstructures were regulated by using 0-5wt.% Dy2O3 as a sintering additive. Mechanical properties and cutting performance of α-SiAlON tool inserts were evaluated. The results showed good Vickers hardness (19.0-19.7GPa) and fracture toughness (3.61-4.18MPa•m1/2) increasing with crack propagation length. However, transverse section of the large elongated grains was revealed as critical crack to cause premature fracture of the α-SiAlON ceramics. Fracture rather than attrition wear was recognized as dominant mechanism for tool failure, indicating that for better cutting performance of the α-SiAlON tool inserts a selftoughening microstructure consisting of thinner grains with large aspect ratio is required.

Ti–6Al–4V alloy, as a typical difficult-to-machine material, is prone to problems such as large cutting forces, high cutting temperatures, and serious tool wear during the cutting process. Ti1-xAlxN coated tools are widely used in machining Ti–6Al–4V alloys. The main wear forms of Ti1-xAlxN coated tools are coating cracking and delamination. After the coating has been delaminated, the tool substrate is in direct contact with the workpiece material, aggravating tool wear and shortening the tool life. Therefore, the milling process of Ti1-xAlxN coated tool cutting Ti–6Al–4V alloy was performed using FEM. The effects of Al contents (Ti0·48Al0·52N, Ti0·38Al0·62N), coating thickness (2, 3, 4 μm), and tool substrate (Cemented Carbide Grade K, M, P) of Ti1-xAlxN coated tools on the cutting performance (cutting force, cutting temperature, maximum principal stress, the temperature and stress of coating-substrate interface) and tool wear were discussed. The influence of the maximum principal stress, the temperature and stress of coating-substrate interface on tool wear were analyzed. This paper can provide a reference for the design and optimization of Ti1-xAlxN coated tools by investigating the wear of Ti1-xAlxN coated tools cutting titanium alloys, which can be used to slow tool wear and prolong tool life.

Preparing a protective coating with high hardness and wear resistance is an economical and practical method to solve the problems of easy abrasion and short service life faced by hard alloy tools when cutting hardened steel.In this paper,AlCrSiN/AlCrMoSiN multilayered composite coatings with different modulation ratios were prepared by high power pulsed magnetron sputtering and pulsed DC magnetron sputtering composite technology.The microstructure and mechanical properties of the multilayered films as well as the cutting performance of the coated tools were characterized and analyzed by scanning electron microscopy,nanoindenter,white light interferometer and other instruments.Results showed that when the modulation ratio was 3:1,the preferential growth orientation of the multilayered film was changed from(111)crystal plane to(200)crystal plane,the surface density of the multilayered film was improved,the layered structure was obvious,and the grains were refined.And at this ratio,the coating hardness was 25.7 GPa,the critical load was 79.6 N,the wear resistance was the highest,the wear rate was 0.74X10-6 mm3/(N·m),and the friction coefficient was the lowest,about 0.45.Using a width of 0.3 mm as the blunting standard for the wear band on the back face,the life of cutting tools coated with AlCrSiN/AlCrMoSiN multilayered composite coating was 1.2 times longer than those coated with AlCrSiN coating and 3.2 times longer than the uncoated tools in case of dry cutting of quenched C1045 medium carbon steel.During the cutting process,some Mo atoms in the multilayered composite coating were oxidized into layered MoO3,which acted as a lubricant and effectively reduced the cutting heat resulting from the cutting force and friction and extended the service life of cutting tools.After a continuous cutting of 25 minutes,the chip color produced by uncoated tool,AlCrSiN coated tool as well as the tool coated with AlCrSiN/AlCrMoSiN multilayered composite coating were getting lighter and lighter and the cutting temperature was getting lower and lower.Through observation and calculation,it could be found that the chip produced by the tool coated with AlCrSiN/AlCrMoSiN multilayered composite coating had the highest saw tooth degree,about 0.36,which was easy to break automatically,and more conducive to the continuous cutting process

Sialon ceramic tool material has become one of the most ideal materials for the high-speed cutting of superalloy materials. However, studies on the geometric structure of sialon ceramic solid end mill is lacking at the present. In this work, the geometric structure of sialon ceramic end mills was designed for difficult-to-machine nickel-based superalloy materials. The cutting force and heat, flank wear and machined surface quality were analyzed to study the effect of the main parameters on tool performance. The results showed that the end mill experienced severe flank wear and chipping, which were the leading cause of its failure during high-speed cutting. The cutting force and temperature decreased gradually with the increase in the helix angle. With the increase in the rake angle, the flank wear and the quality of the machined surface of the specimen first decreased and then increased. With the increase in the relief angle, the cutting temperature of the ceramic end mill gradually decreased, and the cutting force and the machined surface roughness showed an initial decrease and then increased. When the helix angle, rake angle and relief angle were 35°, −15° and 12°, respectively, the sialon ceramic end mill exhibited the best cutting performance and obtained better machined surface quality in the nickel-based superalloys. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the influence of multiple uses of zirconia implant drills on their cutting performance and bending strength. The hypothesis was that drill usage and sterilization cycles would not affect drilling time or flexural strength. Sixty zirconia twist drills from Z-Systems were used to drill in the angulus mandibulae region of fresh porcine jaws. The drills were divided into four groups based on the cycle count, and the drilling time was measured. Bending strength tests were conducted using a universal testing machine, and statistical analysis was performed using ANOVA tests. The results showed that drilling times followed a normal distribution, and significant differences were observed in drilling times between group 1 and the other groups for the pilot drill. However, no significant differences were found for ø3.75 mm and ø4.25 mm drills, and drilling times also varied significantly among different drill diameters, regardless of the cycle count. Flexural strength did not significantly differ among drill diameters or sterilization cycles. Overall, using and sterilizing zirconia implant drills had no significant impact on drilling time or flexural strength. Nevertheless, drilling times did vary depending on the diameter of the drill. These findings provide valuable insights into the performance and durability of zirconia implant drills, contributing to the optimization of dental implant procedures. [ABSTRACT FROM AUTHOR]

In the industrial cutting of alloy GH4169, high cutting force and temperature have always been important factors affecting machining quality and efficiency. In view of this, this study aims to improve the cutting performance of the alloy GH4169, and special attention was given to the changes in cutting force and temperatures under different parameters with ceramic turning experiments, and the optimal cutting parameters were determined based on orthogonal experimental design. The work findings indicate that the resultant force initially increased and then declined with the increase of cutting speed, while it showed increasing trend with the increased of both feed rate and depth of cut. Meanwhile, cutting temperature was positive related to both the cutting speed, feed rate and depth of cut. Based on the range analysis and variance analysis, the depth of cut had the greatest impact on the resultant force and cutting temperature, followed by cutting speed and feed rate, and only the depth of cut significantly affected the changes in resultant force and cutting temperature. Finally, an optimal cutting condition with the lowest resultant force and temperature was determined, where cutting speed is 150 m/min, feed rate is 0.05 mm/r, and depth of cut is 0.1 mm. It is proposed to be used in the industrial machining of alloys GH4169 for the grater product quality and benefits. [ABSTRACT FROM AUTHOR]

The aim of this research is to measure the energy consumption and compare the cutting performance of three types of battery-powered chainsaws (Stihl MSA 200, Stihl MSA 220, and Stihl MSA 300). Tested chainsaws were powered by two different battery packs (Stihl AP 300 S and Stihl AP 500 S) with different energy capacity and output current when cutting two wooden beams, European beech (Fagus sylvatica L.) and black locust (Robinia pseudoacacia L.) with different densities and moisture content. Energy consumption was measured using a multimeter built-in battery charger housing, and consumed energy was noted in watt-hours. Each individual cut was recorded with an action camera at 60 frames per second, and the duration of the cuts recorded in centiseconds was observed on the obtained recordings. Results show significant differences in energy consumption and cutting duration between individual chainsaw/battery combinations. Energy consumption ranged from 2.45 to 4.50 Wh per cut for beech (Stihl MSA300E_AP500S and Stihl MSA220_AP300S, respectively) and from 3.10 to 5.00 Wh per cut for black locust (Stihl MSA300M_AP500S and Stihl MSA220_AP500S, respectively). Duration of the cut ranged from 3.48 to 9.24 s per cut for beech (Stihl MSA300M/H_AP500S and Stihl MSA220_AP300S, respectively) and from 3.74 to 9.35 s per cut for the black locust (Stihl MSA300M_AP500S and Stihl MSA220_AP300S, respectively). In general, it can be concluded that more powerful chainsaw/battery combinations (Stihl MSA300_AP500S) consumed less energy per cut and had better cutting performance (shorter cut). In that regard, more powerful chainsaws had greater cutting efficiency, i.e., more cuts on one charge (battery) but shorter cutting time on one charge. The effect of tree species (fresh-sawed beech/air-dried black locust) on energy consumption and cutting performance is absent on the most powerful chainsaw/battery combinations. Today, lithium-ion batteries still have 70 times less energy density than petrol. However, if there is a significant increase in the energy density of the batteries in the coming times, battery chainsaws will most certainly displace petrol chainsaws from use in the future. [ABSTRACT FROM AUTHOR]

The high chemical activity, low thermal conductivity, and high strength of titanium alloys lead to severe tool wear during cutting. The coating applied to the tool surface insulates the effect of heat and chemical reactions. TiAlSiN coating and AlCrN coating are two representative coatings with excellent properties in TiN-based and CrN-based applications, respectively. Three types of nanocoatings—TiAlSiN monolayer, AlCrN monolayer, and TiAlSiN/AlCrN multilayer—were prepared, and the microstructure, mechanical properties, oxidation resistance, diffusion properties with titanium alloy, and cutting performance of the coatings were investigated utilizing SEM, TEM, XRD, TGA, GD-OES, nanoindentation, and scratching instruments. The hardness, elastic modulus, and adhesion strength of TiAlSiN/AlCrN multilayer coatings are between TiAlSiN monolayer and AlCrN monolayer coatings, which meet the "law of mixtures". Adhesion strength is the primary condition for cutting applications and should have a minimum threshold value. Ti and N elements are the most significant in the diffusion between coatings and titanium alloys. The nitride coating containing Cr aggravates the loss of N in contact with the titanium alloy. In addition, multilayer structural coatings can lead to more severe diffusion than monolayer coatings due to their inherent interlayer defects. Although diffusion between titanium alloys and coated tools is more severe than with other workpiece materials, the main factor affecting tool cutting life is still the H3/E*2 value determined by the hardness and modulus of elasticity together. [ABSTRACT FROM AUTHOR]

ABSTRACTDue to the processing of alumina ceramic cutting tools with complex shapes using traditional methods is difficult and time-consuming, vat-photopolymerization-based 3D printing was adopted to fabricate Al2O3 ceramic cutting tools with grooves for the first time. Subsequently, cutting performance evaluation and wear mechanism analysis were conducted. The relative density, Vickers hardness, and bending strength of the alumina cutting tools were determined. The effects of the cutting speed, feed rate, and cutting depth on the cutting performance and wear mechanism of the cutting tools were systematically investigated. In addition, two commercial cutting tools, namely cemented carbide and ceramic tools without grooves, were used for comparison. The cutting speed has the highest influence on the cutting performance, whereas the cutting depth has the least influence. The cutting performance of the prepared alumina cutting inserts with chip breaker grooves superior to that those without chip-breaking grooves and that of the cemented carbide tools. The wear mechanisms of the prepared alumina cutting tools and commercial tools were determined to be abrasive and adhesive wear, and those of the cemented carbide tools were adhesive wear and breakage. This work opens a new avenue for the future preparation of high-performance and complex-shaped ceramic cutting tools.

Carbide tools are extensively used in the automotive, aerospace, and marine industries. However, an unsuitable tool-edge treatment can affect the cutting performance of carbide tools. In the tool-cutting process, the cutting edge radius is one of the major factors that affect the cutting force, temperature, and quality. In this study, a cutting simulation model of carbide inserts was used to analyze the effect of the cutting edge radius on the cutting performance. The cutting edge radii of the inserts were prepared using shear-thickening polishing methods, followed by cutting experiments. The accuracy of the cutting simulation model was verified through cutting experiments. The simulation results showed that under low-speed cutting conditions, the cutting force and temperature tended to increase with an increase in the cutting edge radius, and the cutting temperature was less affected by the cutting edge radius. The results of the cutting force and cutting temperature obtained from the experiment and simulation were consistent; therefore, the cutting simulation model was verified to be reliable. The results indicate that modeling cutting simulation is a promising research method for predicting the cutting performance of tools.

This paper deals with the concerns of industrial demand for enhancing the machinability of Ti-6Al-4V titanium alloy (TC4). In this regard, the electroplastic effect of high-frequency pulse current can improve the plasticity of the material and reduce the processing resistance of the material. Its application in the processing and manufacturing of difficult-to-machine materials can greatly improve the processing performance. The research compared the effect on turning performance of titanium alloy workpieces after applying 50–400 A (700 Hz) current intensity and 300–1900 Hz (150 A) pulse frequency. Results indicated that the electric pulse–assisted turning (EPT) can promote the plastic flow of grains in the surface layer of Ti-6Al-4V workpiece and then reduce the turning resistance during machining. The residual stress on surface of workpiece after machining can be able to release under thermal effects. In addition, the VB value of tool flank face wear has been reduced in EPT compared to that of conventional turning (CT). It is also found that the change of current intensity has a greater impact in multiple properties during turning process than pulse frequency. [ABSTRACT FROM AUTHOR]