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Copyright of Metal Working (1674-165X) is the property of Metal Working 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.)

Copyright of Teras Jurnal: Jurnal Teknik Sipil is the property of Teras Jurnal: Jurnal Teknik Sipil 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.)

The measurement of the longitudinal rail profile is relevant to the condition monitoring of the rail infrastructure. The running surface is recognizable as a shiny metallic area on top of the rail head. The detection of the running surface is crucial for vehicle-based rail profile measurements, as well as for defect detection. This paper presents a methodology for the automatic detection of the running surface based on a laser profilometer. The detection of the running surface is performed based on the light reflected from the rail surface. Three rail surfaces with different surface conditions are considered. Supervised machine learning is applied to classify individual surface elements as part of the running surface. Detection by a linear support vector machine is performed with accuracy of > 90 % . The lateral position of the running surface and its width are calculated. The average deviation from the labeled widths varies between − 1.2 m m and 5.6 m m. The proposed measurement approach could be installed on a train for the future onboard monitoring of the rail network. [ABSTRACT FROM AUTHOR]

Axle shafts, which are an important part of the vehicle's powertrain system, transfer the torque to the wheels and enable the vehicle to move. In this respect, the design of the axle shaft to be used in a new vehicle is of great importance for vehicle manufacturers. When a cylindrical shaft is torsionally loaded, the shear stress is highest at the surface of component and zero at the center. Therefore, these axle shafts are exposed to an induction hardening process that enables only this superficial case to have its properties changed, remaining the core zone with its material original characteristics. Current study presents the results of a project aimed at developing and evaluating the fatigue life of axle shaft that belongs to a commercial vehicle. Developments were made on the existing axle and the results were examined using experimental tests and finite element analysis method. In line with the improvements made, the developed axle shaft has 331.7% more fatigue life than the existing axle, while the cost is 24% lower. According to these results, more attention must be paid to material selection, induction hardening process, stress concentration and surface condition of axle shaft in the design. This study involves many disciplines such as design, manufacturing, analysis, testing, etc. It is very important to ensure communication between all these disciplines in the production of the product. The output obtained from one discipline becomes the input of another discipline. In the cumulative sum of all these inputs, the optimum level of parts is obtained. For this reason, this study, which processes all these disciplines together, is very valuable. [ABSTRACT FROM AUTHOR]

High-speed steel (HSS) rolls operate in harsh conditions, making them vulnerable to surface degradation. Material removal technology for repairing defective HSS roll surfaces is the most effective way to maintain their integrity and reduce production costs. Electrochemical corrosion machining, with its excellent machining capabilities, offers a promising method for repairing HSS roll surfaces. However, the outer working layer of these rolls is made of premium HSS containing passivating metallic elements, complicating its corrosion behavior, particularly in passivating electrolytes. To elucidate the corrosion behavior and uncover the underlying mechanisms of corrosion and product formation of HSS during electrochemical corrosion machining, this study investigates the electrochemical corrosion process and behavior of M42 HSS used in rolls within a NaH2PO4-Na2SO4 passivating electrolyte. Metallographic etching experiments indicated that M42 HSS comprises a tempered martensitic matrix along with M2C and M6C eutectic carbides. Characteristics of oxidative reactions for M42 HSS in the electrolyte were observed in cyclic voltammetry. By conducting anodic polarization tests, along with thermodynamic analysis and characterization techniques, the entire electrode system was thoroughly examined, including corrosion phenomena, varying processes, and underlying mechanisms of corrosion and product formation. Notably, this study is the first to construct a Pourbaix diagram for the M42 HSS-H2PO4−-SO42−–H2O system. The thermodynamic analysis revealed that the applied potential variation significantly influences corrosion behavior of M42 HSS, confirming by the characterization results. The adsorption phenomenon on the cathodic surface requires a higher potential (such as 6 V) to occur. Electrochemical reactions primarily occur on the anodic surface, while the cathodic surface (or in the electrolyte) mainly engages in chemical reactions with no electronic participation. Furthermore, the electrochemical corrosion process of HSS is driven by one or more corrosion mechanisms, such as galvanic corrosion, pitting, or intergranular corrosion. Therefore, these findings from this study contribute to the development of repairing HSS roll surfaces based on electrochemical corrosion machining in future engineering applications.

Compact tension specimens were fabricated with Ti-6Al-4V titanium alloy by selective laser melting. Some specimens were heat treated and some were hot-isostatic pressed (HIPed). Half of these specimens in three conditions were polished. Fatigue crack growth (FCG) test was conducted to obtain FCG data, and to research into the effect of post-processes. The microstructure and fractography were observed to find possible reasons for FCG variaton. The results indicated that, FCG preformance of as-built SLM Ti-6Al-4V is inferior to conventional material due to the fine needle martensitic structure and large residual stress. Both heat treatment and hot-isostatic pressing lead to thicker o phase and more ß phase, diminsh or even eliminate the residual stress, and improve FCG performance signifcantly. FCG rates of heat treated and HIPed speicmens are comparable to those of Ti-6Al-4V fabricated by conventional techonology. When the crack length and stress intensity factor are larger than a certain value, surface polishing shows haldly any effect.

The AA7075-T6 material is widely used in aerospace applications due to its favourable strength-to-weight ratio and cost-effectiveness. The material undergoes a process of cold rolling and subsequent stretching to form metal sheets. This process generates residual compressive stresses on the surface of the material. Surface changes in the material are observed at low stress levels, resulting in variations in residual stresses and surface roughness. This article presents an approach to monitor the surface state changes of AA7075-T6 material during dynamic loading using Fiber Bragg Grating (FBG) sensor. Numerical Finite Element Method (FEM) simulations analyse the transfer of deformations from the damaged surface through the adhesive layer to FBG with different cladding thicknesses. Loading induces microcrack-related intensity changes in the FBG optical spectrum and deformation response. The magnitude of the response is greater, when the cladding thickness of the optical fibre is thinner. Experimental results show that the FBG optical spectrum response varies with cumulative number of dynamic cycles. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical Strength / Jixie Qiangdu is the property of Zhengzhou Research Institute of Mechanical Engineering 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.)

Modern dental implantology is based on a set of more or less related first-order parameters, such as the implant surface and the intrinsic composition of the material. For decades, implant manufacturers have focused on the research and development of the ideal material combined with an optimal surface finish to ensure the success and durability of their product. However, brands do not always communicate transparently about the nature of the products they market. Thus, this study aims to compare the surface finishes and intrinsic composition of three zirconia implants from three major brands. To do so, cross-sections of the apical part of the implants to be analyzed were made with a micro-cutting machine. Samples of each implant of a 4 to 6 mm thickness were obtained. Each was analyzed by a tactile profilometer and scanning electron microscope (SEM). Compositional measurements were performed by X-ray energy-dispersive spectroscopy (EDS). The findings revealed a significant use of aluminum as a chemical substitute by manufacturers. In addition, some manufacturers do not mention the presence of this element in their implants. However, by addressing these issues and striving to improve transparency and safety standards, manufacturers have the opportunity to provide even more reliable products to patients. [ABSTRACT FROM AUTHOR]

This study investigates the association between surface conditions and pedestrians’ and bicyclists’ route choices during winter. We analyzed responses from two surveys in which pedestrians and bicyclists answered questions regarding their route choices in winter environments. We also conducted an experimental study to investigate the association between surface conditions and route choice. The results indicate that surface conditions have a significant impact on pedestrians’ and bicyclists’ route choice. Specifically, pedestrians avoid slippery surfaces in general, while bicyclists avoid surfaces with a build-up of loose snow on the pavement. When bare pavement is available, some pedestrians change their route from snow- or slush-covered surfaces to walk on a bare surface, even when the amount of snow or slush is minimal. On the other hand, based on the experimental results, a partly ice-covered surface did not deter pedestrians, indicating that a correspondence between actual surface conditions and pedestrians’ visual perceptions is an important factor in their informed decision-making. Decision makers can use the results to gain an understanding of which winter maintenance measures are the most important for implementation in order to provide an acceptable service level that promotes walking and cycling in a winter environment.

In this study, experimental and numerical investigations were carried out to achieve a comprehensive understanding of the impact of surface conditions on self-piercing riveting (SPR) joint quality. Oil lubrication and sandpaper grinding were employed in experimental tests to change surface conditions at rivet/top sheet, top/bottom sheets and bottom sheet/die interfaces. A finite element (FE) model for the SPR process was also adopted to numerically assess the impact of surface conditions. Variations in surface conditions were modelled by changing friction coefficients at contact interfaces. The results revealed that the friction coefficient between the rivet and top sheet (μ1) imposed significant influences on the interlock (I1) by affecting the deformation of the rivet shank and top sheet. The friction coefficient between the rivet and bottom sheet (μ2) showed a lower influence on the joint quality because of a smaller contact area and shorter interaction time. The friction coefficient between the top and bottom sheets (μ3) led to opposite changing trends of remaining bottom sheet thickness at the joint centre (tc) and under the rivet tip (ttip). The friction coefficient between the bottom sheet and die (μ4) demonstrated crucial influences on the remaining bottom sheet at the joint centre. The riveting force was significantly influenced throughout the whole riveting process by the μ1, but only affected at the end of the joining process by the other three friction coefficients. [ABSTRACT FROM AUTHOR]

• The critical Cr content required for Cr 2 O 3 layer formation is identified to be between 26-28 at% for polished surface of Fe-Cr-Ni austenitic alloy in supercritical water at 650°C / 25 MPa. • Increasing the Ni content appears to lower the critical Cr content required for Cr 2 O 3 layer formation. • The process of surface grinding and the increase in Cr and Ni contents exhibit a competitive effect on corrosion resistance, as they share analogous mechanisms for enhancing corrosion resistance. The corrosion behavior of four Fe-Cr-Ni austenitic alloys were investigated after exposure to deaerated supercritical water (SCW) at 650°C. Results show that the corrosion resistance follows the trend:Fe-29Cr-61Ni > Fe-16Cr-75Ni > Fe-25Cr-20Ni > Fe-21Cr-31Ni. The increase in Cr and Ni contents promote a transition from low-protective multilayer oxide scales to protective Cr 2 O 3 scales. After surface grinding, the weight gains of all specimens dropped by one order of magnitude. Surface grinding induces the formation of ultrafine grains and a high density of dislocations, which enhances the corrosion resistance among all studied austenitic alloys. However, the beneficial effects of grinding diminish with increased Cr and Ni contents due to the pre-existing portion of Cr 2 O 3 scales. The lower critical Cr content required to form Cr 2 O 3 scales in high Ni austenitic alloys is primarily attributed to their lower solubility of O and the slower diffusion rates of Ni, which inhibit corrosion behavior. [ABSTRACT FROM AUTHOR]

The problems solved by the chemography method based on fixing oxidative reactions of ultra-low concentrations on the surface of solids are discussed. This method makes it possible to fix physical defects (microcracks, destruction, violations of structural homogeneity) and the energy (residual stresses) state of the surface layer of materials under operating conditions under the action of thermobaric loading. The change in these parameters is associated with the degradation of the cutting surfaces and, as a result, with a change in the rate of the reactions taking place. Applied chemography phenomena as a method of visualization of a destructive layer, a network of surface micro cracks in studying the processes of destruction materials, including nonmetallic ones, is shown. The main advantages of this method are the possibility of assessing the level of residual stresses and periodic visualization of surface defects due to the state of the studied materials, including nonmetallic ones. A relationship has been established between the presence of defects, the level of residual stresses, and the intensity of emerging photo molecular fluxes. In the applied aspect, the method makes it possible to evaluate the performance of cutting plates, and to study the formation and development of a network of microcracks by the intensity of the chemographic effect.

As a prerequisite for successful thermochemical heat treatments such as gas and plasma nitriding, a clean and active steel surface is needed. After multiple machining steps, conservation, transport and storage, passive layers may be present on the surface to be treated. The presence of such layers may inhibit diffusion of molecular nitrogen into the border zone of the steel part, thus leading to problems such as soft-spotting and a lack of compound layer. We developed a method for detection of oil films on steel surfaces using electrochemical impedance spectroscopy. A selection of electrolytes was evaluated regarding corrosiveness to the steel surface, conductivity, and reproducibility to show the suitability of EIS as a method for assessing the surface cleanliness state of steel parts. A certain increase in the charge transfer resistance Rct could be linked to defined amounts of Castrol Rustilo DWX 30 or 7165 Emulsin 5382. Surface coverages as low as 1.7 × 10–2 mg cm−2 of oil are detectable via electrochemical impedance spectroscopy. [ABSTRACT FROM AUTHOR]

This study investigates the association between surface conditions and pedestrians' and bicyclists' route choices during winter. We analyzed responses from two surveys in which pedestrians and bicyclists answered questions regarding their route choices in winter environments. We also conducted an experimental study to investigate the association between surface conditions and route choice. The results indicate that surface conditions have a significant impact on pedestrians' and bicyclists' route choice. Specifically, pedestrians avoid slippery surfaces in general, while bicyclists avoid surfaces with a build-up of loose snow on the pavement. When bare pavement is available, some pedestrians change their route from snow- or slush-covered surfaces to walk on a bare surface, even when the amount of snow or slush is minimal. On the other hand, based on the experimental results, a partly ice-covered surface did not deter pedestrians, indicating that a correspondence between actual surface conditions and pedestrians' visual perceptions is an important factor in their informed decision-making. Decision makers can use the results to gain an understanding of which winter maintenance measures are the most important for implementation in order to provide an acceptable service level that promotes walking and cycling in a winter environment. [ABSTRACT FROM AUTHOR]

In this paper, based on performed experimental research aimed at studying the surface state of powders obtained under conditions of the electroerosive metallurgy of T5K10 hard-alloy waste, we show the high efficiency of the application of electroerosive dispersion technology, which provides the production of spherical powders suitable for practical use at low power expenditures. Hard-alloy powder particles obtained by the electroerosive dispersion of T5K10 hard-alloy waste in both water and kerosene are established to be mainly spherical and elliptical in shape and agglomerates. [ABSTRACT FROM AUTHOR]

The TiAl47Cr2Nb2 alloy fatigue specimens were prepared by investment casting, and three kinds of surface processes were applied to fatigue specimens. These three processes were sand-blasting (SB), sand-blasting and shot-peening (SBSP) and sand-blasting and mechanical grinding (SBMG). The surface condition evolutions before and after thermal exposure at 700 °C for 24 h were investigated. The fatigue performances of specimens after thermal exposure were evaluated. The results show that the surface roughness Ra after SB, SBSP and SBMG processes were 3.14, 2.35 and 0.04 µm, respectively. After thermal exposure, they almost remained unchanged for all three processes. The SB process caused work hardening in the near-surface region and the work hardening reached saturation after the SB process. Due to the mechanical grinding (MG) process removing the uncertain thick hardening layer, the maximum hardness after SBMG process was noticeably lower than those after SB and SBSP processes. After thermal exposure, the maximum hardness after SB, SBSP and SBMG processes significantly recovered. The SBMG specimens had the highest fatigue limit of 350 MPa. This is attributed to the SBMG specimens having very smooth surfaces and some work hardening remaining near their surface layers. [ABSTRACT FROM AUTHOR]

The passivation behaviour of passive films on the surface of reinforcing steels exposed to alkaline solutions was investigated. Two types of reinforcing steels (low-carbon steel and low-alloy steel) with different surface conditions (polished steel with uniform surface and as-received ribbed surface with mill scale) were chosen to compare their passivation capability. Moreover, steels were exposed to high-alkaline simulated concrete pore solution and low-alkaline saturated Ca(OH)2 solution for 10 d to form passive films spontaneously. The results reveal that the passivation capability of steels was significantly affected by the surface condition, whereas the influence of steel type and alkaline solution was relatively less pronounced. [ABSTRACT FROM AUTHOR]

The work carried out is based on the thesis properties of clinched joints are determined by the proportions of binding mechanisms form-closure, force-closure and material-closure. To describe the acting binding mechanisms and thus to derive the joint properties, detailed knowledge of the local effect of the individual binding mechanisms is necessary to ensure their targeted adjustment by the joining process. The targeted setting of different proportions of the binding mechanisms is achieved firstly via tool geometry and secondly via surface condition of the joined parts. An introduced form-closure component can be quantified by metallographic cross section with subsequent measurement of the quality-determining parameters such as undercut, penetration depth and neck thickness. To qualify the force-closure component, a torsional load can be applied mechanically at rotationally symmetrical clinch joints. This also allows the influence of different surface conditions on the tribological system to be quantified. Measurement of electrical resistance can reveal the binding mechanisms of force- and material-closure. These investigations are carried out on an aluminum joining part combination of the same type. As a result of these investigations, the clinched joints can be designed according to the load occurring in the later life cycle in the form of an optimum and compromise variant with regard to minimum loads to be transmitted mechanically, electrically with regard to low resistance or manufacturing with minimum energy input. [ABSTRACT FROM AUTHOR]

The double-layer porous asphalt (DLPA) pavement is a practical way to mitigate traffic noise from the source. However, there hasn't been much research done on the spectral noise characteristics of the car/truck on this type of pavement with different surface conditions yet. The objective of this paper was to reveal these noise characteristics and the behaviors of the DLPA pavement by laboratory tests and field measurements. First, measurements were made of the road performance of different porous asphalt (PA) mixtures and DLPA structures. Then, a vector impedance measurement system was utilized to evaluate the effects of porosity, aggregate size, and thickness on the sound absorption coefficient (SAC) of the DLPA slabs. Third, a sound meter was used to record the noise levels outside/inside the car/truck on the roads with three surface conditions for the DLPA (PA-10+PA-20) and stone matrix asphalt (SMA) test section, which were paved on an elevated urban road. Finally, an analysis was done on the overall and spectral noise characteristics. The results demonstrated good road performance of these PA mixtures and DLPA structures. Relatively fine and coarse aggregates in the upper and lower layers, respectively, enhanced the sound absorption. But an increase in porosity beyond 20 % and a slight variation in thickness did not considerably improve the sound absorption. Compared to SMA pavement, the overall noises levels of the DLPA pavement were 4–8 dBA lower on the "dry" surface and 6 dBA lower on the "wet" surface. The DLPA pavement exhibited a noise reduction at the full frequency band, which attributed to the pore structure and the relatively fine aggregate used. The interior sound energy always concentrated on the low-frequency band. However, the exterior sound energy on the "dry" and "wet" road surfaces tended to the low-frequency and high-frequency bands, respectively. These findings would shed light on the spectral noise characteristics of the DLPA pavement and provide a new knowledge about the behaviors of the lower layer and upper layer in relation to noise reduction and road performance. [Display omitted] • The PA-10+PA-20 structure was measured in the laboratory and test section. • The effects of porosity, aggregate size and thickness were evaluated. • Both the overall and spectral noises were measured and analyzed. • Both the exterior and interior noises were measured and analyzed. • The noises on three road surface conditions were measured and analyzed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The microstructures of high-speed steel influence its electrochemical corrosion. • A Pourbaix diagram of the M42 HSS-H 2 PO 4 −-SO 4 2−–H 2 O system was constructed. • Mechanisms of product formation on the electrode surface exhibit differences. • The electrochemical corrosion process of HSS has one or more corrosion mechanisms. High-speed steel (HSS) rolls operate in harsh conditions, making them vulnerable to surface degradation. Material removal technology for repairing defective HSS roll surfaces is the most effective way to maintain their integrity and reduce production costs. Electrochemical corrosion machining, with its excellent machining capabilities, offers a promising method for repairing HSS roll surfaces. However, the outer working layer of these rolls is made of premium HSS containing passivating metallic elements, complicating its corrosion behavior, particularly in passivating electrolytes. To elucidate the corrosion behavior and uncover the underlying mechanisms of corrosion and product formation of HSS during electrochemical corrosion machining, this study investigates the electrochemical corrosion process and behavior of M42 HSS used in rolls within a NaH 2 PO 4 -Na 2 SO 4 passivating electrolyte. Metallographic etching experiments indicated that M42 HSS comprises a tempered martensitic matrix along with M 2 C and M 6 C eutectic carbides. Characteristics of oxidative reactions for M42 HSS in the electrolyte were observed in cyclic voltammetry. By conducting anodic polarization tests, along with thermodynamic analysis and characterization techniques, the entire electrode system was thoroughly examined, including corrosion phenomena, varying processes, and underlying mechanisms of corrosion and product formation. Notably, this study is the first to construct a Pourbaix diagram for the M42 HSS-H 2 PO 4 −-SO 4 2−–H 2 O system. The thermodynamic analysis revealed that the applied potential variation significantly influences corrosion behavior of M42 HSS, confirming by the characterization results. The adsorption phenomenon on the cathodic surface requires a higher potential (such as 6 V) to occur. Electrochemical reactions primarily occur on the anodic surface, while the cathodic surface (or in the electrolyte) mainly engages in chemical reactions with no electronic participation. Furthermore, the electrochemical corrosion process of HSS is driven by one or more corrosion mechanisms, such as galvanic corrosion, pitting, or intergranular corrosion. Therefore, these findings from this study contribute to the development of repairing HSS roll surfaces based on electrochemical corrosion machining in future engineering applications. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we aimed to establish a novel method for surface condition measurement for the indoor floor. To measure the surface condition, we proposed wiping motion that to stroke the target surface with changing the stroking speed. We developed the wiping device with a 6-axis force sensor, a passive pivot, and a contact plate to realize the wiping motion. In the experiment, the surface condition was measured using four kinds of floor materials and two kinds of liquids. From the experimental results, it was confirmed that the resistance force depends on the wiping velocity. From the experimental results, we confirmed the effectiveness of the proposed method and examined the quantitative index used for surface state description.

Since the development of the Cerchar abrasivity test, various factors affecting the Cerchar abrasivity index (CAI) have been investigated by many researchers. However, some dominant factors, such as surface condition, testing distance, and velocity, are still under discussion due to their sensitivity to the test results. For this purpose, a newly designed Cerchar test device is proposed and applied, by which the testing distance is controlled and the testing velocity can be pre-set and kept constant. Using this device, the effect of some testing condition-based factors on the CAI is studied based on four types of rocks (granite, sandstone, slate, and gneiss). In addition, since not much attention was paid to the effect of rock anisotropy on the CAI, this factor is investigated based on two intact foliated metamorphic rocks, slate, and gneiss. [ABSTRACT FROM AUTHOR]

Impact loading could impair the entire structure or a part of it, thus making the human life at stake. In this study, to improve the impact resistance of reinforced concrete slabs under drop-weight loading, a thin layer of strain-hardening cementitious composites was added at either tension or compression side of the slab. The main parameter of this study was the three contact surface conditions, namely grinding, grinding plus steel dowels, and grinding plus epoxy adhesive, between the substrate slab and the strain-hardening cementitious composites layer. Therefore, 63 reinforced concrete slabs were prepared and tested under the effect of drop-weight falling from three different heights: 1, 1.5, and 2 m. In addition, for comparison purposes, additional seven slabs were tested under central incremental static loading until failure is presented. It was found that the strain-hardening cementitious composites–strengthening layer enhanced the impact and static response of the strengthened slabs when added at either tension or compression side. Besides, to achieve the outermost impact resistance showing ductile performance, it is better to provide a thin layer of the strain-hardening cementitious composites at the tension side of the slab connected to the substrate slab by epoxy resin applied on pre-prepared grinded surface. [ABSTRACT FROM AUTHOR]

This research was conducted to investigate the shear strength at the interface between polymer concrete and asphalt concrete with geotextile as reinforcement at the interface of these two types of concrete. The samples were tested for the parameters of different surface conditions [rough and smooth], curing types [room and thermal curing], temperature effect and the impact of geotextile as reinforcement. To investigate the correlation between these parameters, four different testing conditions were implemented. The results showed a significant improvement of shear strength for rough surface sample as compared to smooth surface sample. Moreover, samples cured in oven had lower shear strength as compared to samples cured in room condition. Besides that, high temperature has an adverse impact on the shear strength at the interface between polymer concrete and asphalt concrete due to the weakening of asphalt concrete at high temperature. As for samples reinforced with geotextile, the shear strength resistance was better as compared to unreinforced samples. Through visual observation, the types of failure under all testing conditions were mixed failure mode. [ABSTRACT FROM AUTHOR]

In order to investigate the temperature variation of cutting surface of 45% SiC_p/Al composites during Gaussian laser irradiating,the temperature variations of 45% SiC_p/Al composites at different phases are calculated based on the Fourier heat transfer theory and the thermal physical properties of silicon carbide particles and aluminum matrix. A finite element model( FEM) is developed for predicting the temperature field in LAM of 45% Si C_p/Al composites. The influence laws of laser power,laser scanning speed,laser spot diameter,and rotational speed on the laser heating temperature field were obtained by FEM simulation. An empirical formula for the temperature at the cutting point from the workpiece surface is established based on the influence law of cutting parameters on heating temperature.The laser assisted cutting experiments of carbide stools and polycrystalline diamond( PCD) cutters are made based on the temperature field obtained by the empirical formula for the temperature at the cutting point. Carbide tools and PCD cutters are used for laser assisted cutting experiment on 45% SiC_p/Al composites. The results indicate that the ratio of aluminum to silicon content is only 1. 187,and the absorption rate of laser is 0. 21. However,the ratio of aluminum to silicon is 1. 047,and the absorption of laser is 0. 23 when the PCD cutters are used. [ABSTRACT FROM AUTHOR]

As the surface conditions play a significant role on corona discharge and its related effects of the conductors, the influence of fine particulate matter on positive-polarity, direct-current conductors was studied experimentally in this study. The surface morphologies of the conductor could be discovered from the experiments. The typical morphologies are the parallel chains of particles. To evaluate the surface condition quantitively, the surface roughness of the conductors is measured. It is found that the applied voltage and testing time have a great influence on the surface condition. After that, the corona characteristics of conductors are tested. It reveals that the total ground level electric field and ion flow density increases with the surface roughness growing.

The parameters of abrasive blasting process directly affect the condition of the metal surface, changing the degree of surface roughness and wettability, depending on the size of the used particle, the pressure or type of abrasive. The aim of this study was to analyze the condition of Ni-Cr alloy surface after abrasive blasting using various process variants. The samples were blasted by Al2O3 abrasive using various particle sizes and pressures of the process. Basic and specific roughness parameters were investigated, and a surface wettability test was performed, and the percentage share of abrasive particles penetrated in the surface after abrasive blasting was also examined. The most considerable differences in the condition of the surface were observed with the change in the particle size of Al2O3. Statistical analysis confirmed the statistical significance of all these relationships. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution 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.)

The formation of a monolithic part during diffusion bonding is accompanied by the diffusion of atoms across the bonding planes. At sufficient low roughness, it mainly depends on the temperature and dwell time. At the same time, the diffusion process competes against grain growth. By adjusting an appropriate level of bearing pressure, it is possible to control deformation taking into account additional parameters resulting from mechanical microstructures and the design and aspect ratio of the part. Furthermore, material properties, such as the content of alloying elements, the degree of cold work hardening and the grain size, have an impact on diffusion and deformation behavior. Also the surface condition of mating surfaces is important to diffusion kinetics and the quality of the joint. Especially passivation layers of corrosion‐resistant alloys, such as stainless steels and nickel‐based alloys, impair diffusion. In contrast to this, cold work hardening at low depth below the surface, e. g. by means of a blasting processes, may facilitate formation of a good bond and help to limit grain size. For oxide dispersion‐strengthened materials, additional impacts on diffusion bonding behavior applies. [ABSTRACT FROM AUTHOR]

The article presents the results of research related to the impact of pretreatment plasma sprayed NiCrAlY coating on the kinetics of the oxidation. The analysis covered the shell subjected to thermal spraying. The test were performed at a temperature of 1000ºC and 1100ºC the samples were removed from the furnace after 25, 300, 500, 750 and 1000 hours. The investigations range included analysis of top surface of coatings by XRD characterization oxides formed types and microscopic investigations of coatings morphology.

Even though required for a robust production, direct measurement of the surface condition in-process is a challenge due to technical limitations. A concept for in-process monitoring of surface conditions like hardness or microtopography using observer-like structures will be discussed in this paper from a metrological point of view. Initially, the background regarding manufacturing and material sciences is summarized. Afterwards, the problem is analysed from a control engineering point of view and challenges and solutions are discussed. Finally, a concept for a new sensor, the opto-pneumatic scattered light sensor, is presented, which contributes to the indirect measurement of the microtophography in-process. [ABSTRACT FROM AUTHOR]