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In order to enhance the efficiency of stone sculpture machining while reducing natural stone waste and environmental pollution, a method for the efficient and green sawing of natural stone sculptures using industrial robots is proposed. The model contour is used as the directrix of the ruled surface to construct a ruled surface model that minimizes volume. The contour curve corresponding to this minimized-volume ruled surface model serves as the machining path for an integrated robotic diamond wire cutting system. A ruled surface model of Stanford Bunny was obtained by sawing a marble block using the robotic diamond wire cutting system. The experimental results show that the material removal rate of the robotic diamond wire cutting is 1.37 times that of saw blade cutting and 2.30 times that of grinding. The volume of stone powder generated during the processing was 0.16×10⁷mm³, accounting for only 1.47% of the total stone powder produced during the grinding process. In summary, the proposed method not only enhances processing efficiency but also reduces natural stone waste and mitigates environmental pollution. [ABSTRACT FROM AUTHOR]

Sapphire crystal with excellent properties is widely used as substrate materials for optoelectronics and microelectronics industries. Subsurface crack damage (SSD) will occur in the diamond wire saw slicing process of the sapphire wafer, which is related to the quality of the as-sawn wafer and the cost of subsequent processing. Therefore, rapid and effective detection of SSD is required in production. However, current detection methods are time-consuming and labor-intensive, thus requiring a fast, effective, and low-carbon evaluation method. In this paper, based on the current diamond wire saw slicing process parameters range of sapphire crystal in actual production, sawing experiments were carried out to study the surface and subsurface crack damage morphology characteristics, evolution law of surface roughness (Rz), and SSD. Furthermore, the mapping relationship between Rz and SSD was established by the numerical fitting method. The results show that, in the range of processing parameters for practical industrial applications, the surface of the as-sawn wafer was mainly formed by material brittleness removal, the subsurface presented a small number of micro-cracks and brittle fracture damage, and the median crack propagation direction was shifted. Within the range of process parameters used in this study, the maximum SSD value of the sapphire wafer is 20.07 µm, the minimum value is 11.67 µm, and the corresponding Rz values are 11.13 µm and 8.12 µm, respectively. Both SSD and Rz decreased with the increase in saw wire speed and the decrease in specimen feed speed. There is a nonlinear relationship of monotone increase between the two, which is SSD = 0.15Rz3 − 4.87Rz2 + 55.49Rz − 195.23. The research results can be used to evaluate SSD quickly and effectively by measuring as-sawn sapphire wafer Rz that can provide an experimental reference for wire-sliced SSD evaluation, wafer quality improvement, and processing parameter optimization. [ABSTRACT FROM AUTHOR]

Electroplated diamond wire sawing is widely used as a processing method to cut hard and brittle difficult-to-machine materials. Currently, obtaining the sawing capability of diamond wire saw through the wire bow is still difficult. In this paper, a method for calculating the sawing capability of diamond wire saw in real-time based on the wire bow is proposed. The influence of the renewed length per round trip, crystal orientation of sapphire, wire speed, and feed rate on the wire sawing capability has been revealed via slicing experiments. The results indicate that renewing the diamond wire saw, and reducing the wire speed and feed rate can delay the reduction in sawing capability. Furthermore, controlling the value of renewed length per round trip can make the diamond wire saw enter a stable cutting state, in which the capability of the wire saw no longer decreases. The sawing capability of diamond wire saw cutting in the A-plane of the sapphire is smaller than that of the C-plane, and a suitable feed rate or wire speed within the range of sawing parameters studied in this study can avoid a rapid decrease in the sawing capability of the wire saw during the cutting process. The knowledge obtained in this study provides a theoretical basis for monitoring the performance of the wire saw, and guidance for the wire cutting process in semiconductor manufacturing. In the future, it may even be possible to provide real-time performance parameters of diamond wire saw for the digital twin model of wire sawing. [ABSTRACT FROM AUTHOR]

In diamond wire saw cutting monocrystalline silicon (mono-Si), the material brittleness removal can cause microcrack damage in the subsurface of the as-sawn silicon wafer, which has a significant impact on the mechanical properties and subsequent processing steps of the wafers. In order to quickly and non-destructively obtain the subsurface microcrack damage depth (SSD) of as-sawn silicon wafers, this paper conducted research on the SSD prediction model for diamond wire saw cutting of mono-Si, and established the relationship between the SSD and the as-sawn surface roughness value (SR) by comprehensively considering the effect of tangential force and the influence of the elastic stress field and residual stress field below the abrasive on the propagation of median cracks. Furthermore, the theoretical relationship model between SR and SSD has been improved by adding a coefficient considering the influence of material ductile regime removal on SR values based on experiments sawing mono-Si along the (111) crystal plane, making the theoretical prediction value of SSD more accurate. The research results indicate that a decrease in wire speed and an increase in feed speed result in an increase in SR and SSD in silicon wafers. There is a non-linear increasing relationship between silicon wafer SSD and SR, with SSD = 21.179 Ra4/3. The larger the SR, the deeper the SSD, and the smaller the relative error of SSD between the theoretical predicted and experimental measurements. The research results provide a theoretical and experimental basis for predicting silicon wafer SSD in diamond wire sawing and optimizing the process. [ABSTRACT FROM AUTHOR]

Diamond wire saws are indispensable machines for the extraction and processing of dimension stones. The cutting speed, energy consumption and wear rate of the diamond beads are the most important factors in assessing the efficiency of a diamond wire saw. The parameters that influence the efficiency of the diamond wire saw can be divided into controlled and uncontrolled parameters. Uncontrolled parameters cannot be influenced directly and are related to the rock types and their properties such as strength, hardness and abrasiveness. Controlled parameters are related to the operating parameters and technical characteristics of the machine. The energy consumption and the service life of the diamond wire are directly related to the characteristics of the machine and the design of the diamond wire, such as the power of the drive motor, the diameter of the drive wheel, diamond grit size and the diameter of the wire. The operating parameters of the diamond wire saw, such as cutting speed, cutting surface, cutting angle, wire tension and cooling water flow, also have a significant influence. Based on previous studies, the influence of the above parameters on the consumption of energy and wear rate of diamond beads in the operation of a diamond wire saw was analyzed.

Due to the anisotropy of sapphire crystal material, the mechanical properties vary in multi-wire saw slicing based on different cutting positions. This variation leads to the deviation of the diamond wire in the vertical feed direction, resulting in the surface shape deviation of the sapphire wafers. To further investigate the influence of crystal anisotropy on the surface shape deviation of the wafer, the properties of sapphire crystal material were analyzed, and the distribution of the elastic modulus of its common crystal surfaces was calculated. By simulating the sawing force, the surface shape deviation of the wafer was calculated, and the influence of process parameters on the surface shape deviation was analyzed. The results show that the surface shape deviations of wafers cut from the C-plane, A-plane, and M-plane are not affected by the anisotropy of sapphire. A feed angle of 90° or 270° can be selected to obtain a small surface shape deviation during the slicing process of the R-plane. Additionally, reducing the specific feed rate or adopting the variable speed feed method can reduce the wafer's surface shape deviation.

Copyright of e-Zbornik: Electronic Collection of Papers of the Faculty of Civil Engineering is the property of University of Mostar, Faculty of Civil Engineering, Architecture & Geodesy 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 Diamond & Abrasives Engineering is the property of Zhengzhou Research Institute for Abrasives & Grinding 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 e-Zbornik: Electronic Collection of Papers of the Faculty of Civil Engineering is the property of University of Mostar, Faculty of Civil Engineering, Architecture & Geodesy 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 diamond wire sawing technology has been widely used in cutting sapphire crystal, and the surface roughness and morphology of as-sawn sapphire wafers are important indexes of the cutting quality. With the development of diamond wire saw cutting technology to high wire speed, this paper conducted diamond wire sawing sapphire crystal experiments within the industrial high saw wire speed of 1000–1600 m/min, and the effect of cutting parameters on the as-sawn wafers surface roughness and morphology was analyzed. Furthermore, a diamond wire saw cutting numerical calculation model was established based on the wire sawing mechanism and sapphire crystal material removal mechanism, and the model was verified by sawing experiments. The influences of abrasive density and size on the surface roughness of the as-sawn wafers were predicted using the sawing model which provides a theoretical reference for the rationally adopting saw wire parameters to improve the cutting quality of sapphire crystal under industrial cutting parameters. The results show that within the range of parameters studied in this paper, the sapphire crystal material is mainly removed in brittle mode. Increasing saw wire speed from 1000 to 1400 m/min and decreasing specimen feed speed from 0.5 to 0.05 mm/min, increasing the abrasive density, and decreasing the abrasive size are all beneficial to decrease the as-sawn wafers surface roughness. Increasing the saw wire speed and decreasing the feed speed are beneficial to reduce the number of brittle pits and saw marks, the period of waviness on the as-sawn wafer surface, and improve the as-sawn wafer surface morphology. [ABSTRACT FROM AUTHOR]

To optimize the parameters of slicing ferrite with high precision diamond ring saw, an orthogonal test is designed with the fabricating surface accuracy and the surface roughness as evaluation indicators and the spindle speed, the feed speed and the tension force as factors. Based on the grey theory, the data analysis and the comprehensive evaluation of the multiple process targets are carried out to obtain an optimized process parameter combination, namely the spindle speed 1 000 r/min, the feed speed 1.0 mm/min and the tension force 90 N. The slicing test results show that the optimized parameter combination can obtain a surface accuracy of PV 7.37 μm and a surface roughness Ra of 0.882 μm, and the slicing surface quality is improved, which verifies the effectiveness and practicability of this method in the optimization of ferrite slicing process parameters.

• Obtained the fracture strength of mono-Si wafers by bending tests and simulation. • The fracture strength of mono-Si wafers exhibits strong anisotropy. • The anisotropy of fracture strength is due to different load-bearing cracks. • Relationship between roughness, saw marks with the fracture strength is revealed. Diamond wire slicing technology is the main method to manufacture the substrate of the monocrystalline silicon-based solar cells. With the development of technology, the size and thickness of monocrystalline silicon wafer are respectively getting larger and thinner, which cause an increase in silicon wafer fracture probability during wafer processing and post-processing. And the change of the sawing speed, saw wire diameter and abrasive size also affect the wafer's surface characteristics, thereby affect its fracture strength. In this paper, monocrystalline silicon wafer with large size of 210 mm × 210 mm was taken as the research object, 4-point bending test was carried out on each series of silicon wafers. The load–displacement curves during bending test were collected, and the fracture stress values were calculated by finite element method. The characteristic fracture strength and Weibull modulus of each series of silicon wafers were obtained through the statistical analysis of the data using Weibull distribution function. The effect of the silicon wafer thickness, the position of the silicon wafer in the silicon brick (usage time of the saw wire varies), and the bending test direction on the fracture characteristics was analyzed. The results showed that the increase of thickness increase the characteristic fracture strength of silicon wafer. The characteristic fracture strength of the front wafers (sawn by the fresh wire) is the smallest, while the characteristic fracture strength of the middle wafers and the rear wafers (sawn by the worn wire) are similar. The characteristic fracture strength of bending in the direction of perpendicular to the saw marks is 2–3 times that of bending in the direction of parallel to the saw marks. The reason of the difference of characteristic fracture strength was analyzed based on the surface morphology, roughness, and the saw marks of silicon wafer. In this paper, the fracture characteristics of large size monocrystalline silicon wafer are studied to provide fracture data support for industry production. The mechanism and main effect factors of silicon wafer fracture are revealed, which provides directions for improving the sawing quality and reducing the fracture probability during wafer production process and post-processing. [ABSTRACT FROM AUTHOR]

[Display omitted] • An analytical model for the initiation and deflection of the surface radial crack is proposed. • Driving forces for the initiation and deflection of radial cracks are analyzed. • Effects of 4H-SiC anisotropy on cracking behavior and mechanical properties are investigated. Cracking behavior caused by the anisotropy of single-crystal silicon carbide (SiC) brings challenges to the quality of the diamond wire sawing and grinding process. In this study, the effects of SiC anisotropy on machanical properties is analyzed based on Griffith's theory. The results indicate that the fracture toughness and the fracture strength exhibit anisotropy. At the same time, an analytical model for the initiation and deflection of the surface radial crack is proposed based on the scratching stress field. On the basis of these results, the anisotropic machanism of the surface radial crack initiation, deflection, the surface radial crack initiation (SRCI) depth, and the residual scratching depth are investigated in combination with the single abrasive scratching experiment. The shear stress and the maximum principal stress are the primary driving forces for the initiation and deflection of surface radial crack, respectively. The direction of the minimum shear strength and the fracture strength determines the anisotropy of cracking behavior. Meanwhile, the anisotropy of the SRCI depth and the residual scratching depth is caused by the fracture strength anisotropy. This research offers fundamental insights into the anisotropic cracking behavior of SiC, thereby contributing to the precise control of crack damage and improve the quality of the SiC diamond wire sawing and the as-cut wafers grinding process. [ABSTRACT FROM AUTHOR]

The electroplated diamond wire saw has been widely used in the production of semiconductors, photovoltaic devices, etc. Composite electroplating is an important process in the production of electroplated diamond wire saws. The utilization of nickel (Ni)-coated diamonds is a widely adopted approach to enhance the efficiency of the composite electroplating process employed in the manufacturing of wire saws. However, the pristine diamond does not chemically react with Ni, and the interfacial bonding strength between the Ni coating and the diamond is relatively weak. This frequently results in the detachment of diamonds from the Ni coating during the cutting process. To solve this problem, titanium (Ti)-coated diamonds were used in the preparation of wire saws. We had specially developed a vacuum slow evaporation technology to produce diamond micro-powder (8 μm) with uniform conductive Ti coatings that were firmly bonded with diamond through the interfacial product TiC. A series of electrochemical test results were used to demonstrate the effect of Ti coating on the composite electroplating process. The linear scanning voltammetry curves showed that the addition of Ti-coated diamond shifted the overpotential of composite electroplating in a positive direction, so it promoted the electrodeposition reaction more than diamond powder. The electrochemical impedance spectroscopy revealed that the conductive Ti-coated diamond reduced the charge transfer resistance during composite electroplating. The Ti-coated diamond micro-powder was completely enveloped by an electroplated Ni layer, and TiC formed between the Ti coating and the diamond provided a stronger interfacial bonding force compared to that of the Ni-coated diamond micro-powder. After cutting, the Ti-coated diamond was found not to fall off the wire saw. The use of Ti-coated diamond micro-powder as an abrasive will significantly improve the product quality of mass-produced electroplating diamond wire saws. [Display omitted] • Ti-coated diamond was prepared by vacuum slow evaporation technology. • Uniform Ti coating was chemically bonded to diamond by interfacial product TiC. • Ti-coated diamond wires exhibited superior resistance to abrasives fall off. [ABSTRACT FROM AUTHOR]

When diamond wire saw is used in machining silicon nitride ceramics (Si 3 N 4 ceramics), the ultra-hardness of Si 3 N 4 causes the saw wire to wear out, which leads to the saw wire cutting performance constantly changing during its life cycle, and thus the machined quality of Si 3 N 4 ceramics is affected. Surface roughness and topography are important indicators of the quality of the machined surface. In this paper, the diamond wire saw cutting experiment of Si 3 N 4 ceramics was carried out, the effect of the evolution of saw wire cutting performance on the surface roughness and topography of Si 3 N 4 ceramics as-sawn slices was investigated based on the analysis of the changes of saw wire wear topography, breaking force, bow angle and kerf loss during the sawing process. The results show that the surface roughness along the saw wire motion direction and the workpiece feed direction tends to decrease and then increase with the evolution of the cutting performance of the saw wire, which accords well with the trend of the as-sawn slices surface morphology. The results of the study can provide experimental reference for the development of high precision diamond wire saw cutting technology for Si 3 N 4 ceramics. [ABSTRACT FROM AUTHOR]

Diamond wire saw cutting technology has been widely used in the slicing of sapphire crystal. The ultra-high hardness of sapphire makes the sawing characteristics of diamond saw wire constantly change. At present, there is a lack of in-depth understanding about the influence of sawing characteristics on the quality of sapphire as-sawn wafer, which leads to the unreasonable matching between the process parameters and the sawing characteristics of the saw wire, and reduces the as-sawn wafer quality and the saw wire life. In this paper, the slicing sapphire crystal experiment was carried out with constant process parameters and the variation of saw wire bow angle, nominal diameter and saw kerf loss, surface morphology and surface roughness of the as-sawn wafer during the whole life cycle of the saw wire from initial cutting to breakage was studied. The evolution mechanism of wear and sawing characteristics in the whole life cycle of saw wire was explored, and a reasonable processing scheme which can match the sawing characteristics was put forward. The research results show that in the whole life cycle of the saw wire, the abrasives emerge from the plating layer in turn, then the cutting edge are blunted, and finally the abrasives are greatly flattened and a small amount of falling off. Saw wire has experienced initial wear, stable wear and sever wear, and the proportion of three stages in the whole life cycle is about 0.3: 0.6: 0.1. Compared with the initial stage of wear and the late stage of rapid wear, the saw wire has higher sawing characteristics and better as-sawn wafer quality in the middle stable wear period. The sawing characteristics of new saw wire is relatively weak at the beginning of cutting, so the feed speed of workpiece should be increased gradually from low to high; When most of the abrasives finish sharpening edge, a relatively stable and high feed speed can be adopted; When the abrasives are obviously flattened or fall off, the feed speed should be decreased to accommodate the significantly reduced. cutting performance of diamond saw wire. [ABSTRACT FROM AUTHOR]

Diamond wire sawing has been developed to reduce the cutting loss when cutting silicon wafers from ingots. The surface of silicon solar cells must be flawless in order to achieve the highest possible efficiency. However, the surface is damaged during sawing. The extent of the damage depends primarily on the material removal mode. Under certain conditions, the generally brittle material can be machined in ductile mode, whereby considerably fewer cracks occur in the surface than with brittle material removal. In the presented paper, a numerical model is developed in order to support the optimisation of the machining process regarding the transition between ductile and brittle material removal. The simulations are performed with an GPU-accelerated in-house developed code using mesh-free methods which easily handle large deformations while classic methods like FEM would require intensive remeshing. The Johnson-Cook flow stress model is implemented and used to evaluate the applicability of a model for ductile material behaviour in the transition zone between ductile and brittle removal mode. The simulation results are compared with results obtained from single grain scratch experiments using a real, non-idealised grain geometry as present in the diamond wire sawing process. [ABSTRACT FROM AUTHOR]

Due to their excellent physical and mechanical properties, third-generation super hard semiconductor materials (such as SiC, GaN) are widely used in the field of microelectronics. From the crystal bar to electronic devices, slicing is the first machining procedure that directly affects the subsequent process. Fixed diamond wire saw has been widely used in cutting hard and brittle materials. However, the diamond grits of wire saw are bonded through the binding agent's mechanical embedding that slicing super hard crystal is very difficult and inefficient. In order to improve the slicing efficiency, it is necessary to improve the holding strength and wear resistance of the diamond wire saw. The electro-spark deposition (ESD) process can form metallurgical bonding between metal materials at low heat input. The holding strength and wear resistance of the diamond wire saw can be effectively improved. In this paper, the mechanism of the manufacturing process of ESD diamond wire saw (ESDDWS) is introduced, and the conditions of the manufacturing process of ESDDWS are put forward. A model of the surface heat source of saw wire is established considering the wire shape. The transient thermal analysis of the single discharge of ESDDWS is carried out in ANSYS, and the effect of material compaction on material physical properties is considered. According to the simulation results, the parameter range of the manufacturing process of ESDDWS is predicted. The predictions agreed with experiment observation. [ABSTRACT FROM AUTHOR]

KDP crystal is an important functional crystal material used in the fields of laser frequency conversion. Slicing is the first process of KDP crystal processing and the KDP crystal is usually sliced by the diamond wire saw. As KDP crystal is an anisotropic material, the properties of KDP contact with different diamond grits on the diamond wire saw during slicing would be different. The anisotropic properties may lead to the deviation of the diamond wire saw in the thickness direction and form the surface shape deviation of slice. The surface shape deviation would affect the amount of material to be removed and the accuracy of crystal positioning. The commonly used crystal planes of KDP crystal are the (001), the double-frequency, and the triple-frequency crystal plane. In this paper, a model of diamond wire saw considering the anisotropy of KDP crystal is established to obtain the sawing forces, while the anisotropic properties of KDP crystal used in slicing are obtained through coordinate changes. The obtained sawing forces are then applied to the diamond wire saw to obtain the surface shape deviation. Besides, the influence of the tension force on the surface shape deviation is also considered. Based on the established model, the variation rule of surface shape deviation with the feed angle of diamond wire saw is obtained. Results in this paper can reduce the surface shape deviation of slice caused by the anisotropic properties of KDP crystal. [ABSTRACT FROM AUTHOR]

Assessment of wear rate is an inseparable section of the saw ability of dimension stone, and an essential task to optimization in the diamond wire saw performance. This research aims to provide an accurate, practical and applicable model for predicting the wear rate of diamond bead based on rock properties using applications and performances of intelligent systems. In order to reach this purpose, 38 cutting test results with 38 different rocks were used from andesites, limestones and real marbles quarries located in eleven areas in Turkey. Prediction of wear rate is determined by optimization techniques like Multilayer Perceptron (MLP) and hybrid Genetic algorithm –Artificial neural network (GA-ANN) models that were utilized to build two estimation models by MATLAB software. In this study, 80% of the total samples were used randomly for the training dataset, and the remaining 20% was considered as testing data for GA-ANN model. Further, accuracy and performance capacity of models established were investigated using root mean square error (RMSE), the coefficient of determination (R2) and standard deviation (STD). Finally, a comparison was made among performances of these soft computing techniques for predicting and the results obtained indicated hybrid GA-ANN model with a coefficient of determination (R2) of training = 0.95 and testing = 0.991 can get more accurate predicting results in comparison with MLP models.

Lower warp is required for the single crystal silicon wafers sawn by a fixed diamond wire saw with the thinness of a silicon wafer. The residual stress in the surface layer of the silicon wafer is the primary reason for warp, which is generated by the phase transitions, elastic-plastic deformation, and non-uniform distribution of thermal energy during wire sawing. In this paper, an experiment of multi-wire sawing single crystal silicon is carried out, and the Raman spectra technique is used to detect the phase transitions and residual stress in the surface layer of the silicon wafers. Three different wire speeds are used to study the effect of wire speed on phase transition and residual stress of the silicon wafers. The experimental results indicate that amorphous silicon is generated during resin bonded diamond wire sawing, of which the Raman peaks are at 178.9 cm−1 and 468.5 cm−1. The ratio of the amorphous silicon surface area and the surface area of a single crystal silicon, and the depth of amorphous silicon layer increases with the increasing of wire speed. This indicates that more amorphous silicon is generated. There is both compressive stress and tensile stress on the surface layer of the silicon wafer. The residual tensile stress is between 0 and 200 MPa, and the compressive stress is between 0 and 300 MPa for the experimental results of this paper. Moreover, the residual stress increases with the increase of wire speed, indicating more amorphous silicon generated as well.

Slicing is the initial procedure in silicon wafer manufacturing process. The cost of slicing process is about 30% of the total cost of chip fabrication. The effective approaches to decrease slicing cost are to reduce the slicing kerf loss and to decrease the thickness and breakage ratio of sliced wafer. The resin-bonded diamond wire saw has the advantages of uniform of abrasive protrusion height and the manufacturing process less impact on the core wire strength. It is expected to achieve a narrow kerf and ultra-thin wafer slicing of silicon crystal ingot with resin-bonded diamond wire saw. The aim of this paper is to develop high-performance resin-bonded diamond wire saw. Based on the analysis of fabrication process of resin bond diamond wire saw, the device for resin-bonded diamond wire saw manufacturing is developed. The mold in the fabrication device ensures the consistency of the wire saw outer diameter and the uniform of abrasive protrusion height. A test device for constant force feed slicing is developed for the slicing performance evaluation of resin-bonded diamond wire saw. The components of the coating layer materials of resin-bonded diamond wire saw are investigated via orthogonal test. Choosing the material removal rate, wire saw wear rate, coating layer binding force, and sliced surface roughness as evaluation indexes, the performance of developed resin-bonded diamond wire saw is evaluated. The optimal component ratio of the coating layer materials of resin-bonded diamond wire saw is obtained, and the verification test of the optimal component ratio of the coating layer materials is performed. The results of this paper are useful for the development of smaller-diameter diamond wire saw and high-quality slicing of optoelectronic crystal ingot. [ABSTRACT FROM AUTHOR]

Having a unique physical characteristics and stable semiconductor properties,silicon carbide（ Si C） monocrystal wafer has been widely used in integrated circuits,space optics and other fields.In manufacturing process of Si C monocrystal wafer,cutting is primary key process,which the cutting costs accounts for more than 50% of the whole wafer processing costs.In this paper,the datum and relevant literature of domestic and foreign were reviewed to,the current research status of Si C cutting technology,especially cutting with wire saw,and cutting equipment were studied.Moreover,the existing problems in Si C cut by wire saw and in cutting equipment was analyzed.It is proposed that the future researching direction of Si C wafer cutting technology by wire saw.

Predicting the wear rate of diamond beads in the diamond wire sawing process is one of the most important factors in the optimized design and cost estimation of quarrying. This paper aims to predict the wear rate of diamond beads as one of the principal performance criteria in dimension stone quarrying. Saw operating parameters and mechanical and physical properties of rock are the most effective factors on diamond bead wear. In the same working conditions (at constant operating parameters), the wear rate of diamond wire saw is strongly affected by the production rate, and the characteristics of rock. In this study, the uniaxial compressive strength, Schmiazek abrasivity factor, Mohs hardness, and Young's modulus were selected as the main physical and mechanical properties of rock. The 11 types of igneous rocks were cut in the laboratory using a diamond wire saw and a fully instrumented cutting platform. During the cutting process, the wear rate of diamond beads were determined after each cutting test. The wear rate of diamond bead and rock characteristics were evaluated using simple and multiple curvilinear regression analysis, and prediction models were developed. The developed models were validated by considering the t-test, F-test, correlation coefficient and the plots of predicted versus actual values. The results indicated that the wear rate of diamond beads can be reliably predicted using the developed model. [ABSTRACT FROM AUTHOR]

During recent years, diamond wire sawn (DWS) multicrystalline silicon (mc-Si) wafers have been widely used to reduce the production costs; however, these wafers need additional process treatments such as reactive ion etching (RIE) or metal-catalysed chemical etching (MCCE) to form a surface with relatively low reflectivity. Although the absolute power conversion efficiency of the solar cell could be improved by 0.3-0.5% through the introduction of such surface treatments, the production costs would also be increased. In this study, an improved production-scale acidic texturization with additives is used to texture the surfaces of DWS mc-Si wafers, giving a similar weighted averaged reflectance (WAR) of 19.69% as slurry-cut wafers. The effect of the texturization process on the surface morphology, WAR and performance of the DWS mc-Si cells is discussed. [ABSTRACT FROM AUTHOR]

In this study, the variation in diamond wire tension during the reciprocating wire-winding machining process is investigated to improve the cutting stability and machining precision of a reciprocating winding diamond wire saw. Furthermore, the main causes of wire tension variation are analyzed, a tension control method using a PI (proportional-integral) regulator is proposed, and a wire tension detection and control mechanism is developed to solve the problem of tension variation during the machining process. The performance of this mechanism is verified through experiments, in which polycrystalline silicon materials are cut. Experimental results show that the designed mechanism can effectively mitigate tension instability during the reciprocating wire-winding machining process, control the wire tension fluctuation within 0.6 N, and significantly improve cutting efficiency, cutting surface roughness, and machining dimension accuracy. [ABSTRACT FROM AUTHOR]

Wire deflection affects the shape precision of workpiece during the profile cutting process with diamond wire saw. This study proposes a method for solving this problem using wire deflection detection, called light projection method. This method is based on the space position of the diamond wire. This research also analyzes the effects of wire deflection on shape precision, develops a detection and control device that allows feedback control according to the change in wire projection position, judges the wire position change, and uses this device to perform validation tests with polycrystalline silicon materials. The test shows that this detection and controlling device can effectively control the wire deflection phenomenon in the process of diamond wire cutting process. The roundness of a polysilicon with 20 mm thickness and φ20 mm diameter can be controlled within 0.05 mm, enabling significant improvement in the cutting shape precision and cutting stability. [ABSTRACT FROM AUTHOR]

• The effect of industrial process parameters on SSD of DW sawn sapphire was studied. • A mathematical model for calculating SSD of DW sawn sapphire was proposed. • The effect of DW abrasive parameters on sawn sapphire SSD was studied. Sapphire crystals are widely used as window materials for infrared emitting devices, high intensity lasers, optical elements and microelectronic substrates due to the excellent material properties. The subsurface microcrack damage produced by diamond wire saw when cutting sapphire crystal is an important indicator of the cutting quality. In this paper, diamond wire sawing experiments were conducted within the industrial production processing parameters to investigate the as-sawn sapphire crystal wafers subsurface microcrack damage depth (SSD), and a numerical calculation model was established to predict the SSD based on the analysis of the scratching stress field of single abrasive. The effects of the saw wire speed and specimen feed speed, saw wire parameters on SSD were predicted. The results show that, within the parameters studied in this paper, the material was removed in brittle mode, increasing the saw wire speed (from 1000 m/min to 1600 m/min) and reducing the specimen feed speed (from 0.5 mm/min to 0.05 mm/min) can reduce the sapphire as-sawn wafers SSD, reduce the size of brittle tear-shape edge breakage, the number and size of brittle pits on the as-sawn wafer surface are reduced and the surface morphology consistency is improved. Increasing the abrasive density and reducing the abrasive size can reduce the SSD. The study results provide a reference for the reasonable matching of sawing process parameters and saw wire parameters in industry. [ABSTRACT FROM AUTHOR]

• An analytical model of minimum sawing thickness of silicon wafer is based on Kirchhoff's thin plate theory. • The analytical model is verified by the finite element simulation. • The experiment of the minimum thickness of diamond wire saw cutting monocrystalline silicon wafer is accomplished to validate the theory. Diamond wire sawing is one of the key technologies in solar cell manufacturing process and semiconductor chip manufacturing process. The thinned of silicon wafer has become a development trend of semiconductor industry, and the reduction of silicon wafer thickness can improve the material utilization and reduce the manufacturing cost. Therefore, the minimum thickness analytical model of diamond wire saw cutting monocrystalline silicon wafer is proposed in this paper to study the processing mechanism of minimum thickness of monocrystalline silicon wafer. Firstly, based on the Kirchhoff's thin plate theory, the theoretical equation of the maximum internal stress of single silicon wafer and the sawing thickness of the silicon wafer is derived from the sawing force model. Combined with the Mohr's strength theory, the analytical model of minimum sawing thickness of monocrystalline silicon wafer is established. Then, the analytical model is verified by the finite element simulation. The average error between the simulation results and the calculation results of the analytical model about the minimum sawing thickness of silicon wafer is 9%. Finally, the monocrystalline silicon sawing verification experiments are conducted under some groups of processing conditions. The experimental results show that the minimum sawing thickness of the silicon wafer decreases with the increasing axial speed of the wire saw, increases with the increase of the feed rate of the wire saw, and decreases first and then increases with workpiece speed becoming large. The average error of the experimental results and the calculation results of the analytical model of the wafer minimum sawing thickness is 7.4%, which verifies corrections of the analytical model. [ABSTRACT FROM AUTHOR]

Diamond wires from several manufacturers were investigated in term of their impact on wafer quality and cell performance. It was identified that under identical ingot sawing conditions the diamond wire make had an impact on the resulting cell performance. Several cells exhibited defects that remained with the cell even after the saw damage etching process. These defects were investigated in terms of there impact on various solar cell performance parameters. This analysis was performed using photoluminescence imaging and spatially resolved quantum efficiency and reflectance measurements. The diamond wire marks were observed to have the largest impact on the local short-circuit current density across the cell. [ABSTRACT FROM AUTHOR]

It is difficult to machine SiC single crystal slicing by diamond wire saw due to the high hardness and brittleness of SiC single crystal, the high wear speed of machine tool, low machining efficiency and high possibility of fragment and damage on the slicing surface or subsurface. So the manufacturing technology is critical to produce high-quality SiC single crystal slicing and high performance saw wire. In this paper, recent progress of manufacturing technology of SiC single crystal wire saw slicing and electroplated diamond wire saw is summarized. The problems in machining process are reviewed and analyzed. The research trend on SiC single crystal wire saw slicing technique is also presented. [ABSTRACT FROM AUTHOR]

Experimental results from fixed abrasive diamond wire machining of wood and foam ceramics are presented. Three types of wood—pine, oak, and fir, and three types of foam ceramic—silicon carbide, zirconia, and zirconia toughened alumina, are tested. The research investigates the life of diamond wire and effects of process parameters on the cutting forces, force ratio, and surface roughness. A scanning electron microscope is used to study the worn diamond wire, machined surfaces, and debris. The diamond wire saw is demonstrated to be very effective in machining foam ceramics. The wire life for cutting wood at slow feed rates is low. The short tool life for dry cutting of wood indicates that more research in new fixed abrasive diamond wire and wire saw machining technologies is necessary. [Copyright &y& Elsevier]

The process monitoring and mechanics of fixed abrasive diamond wire saw machining are investigated in this study. New techniques to affix diamond particles to a steel wire core have advanced to make this process feasible for the machining of ceramics, wood, and foam materials. Developments in fixed abrasive diamond wire machining are first reviewed. Advantages of using fixed abrasive diamond wire machining are then introduced. The process monitoring and signal processing techniques for measuring the cutting forces, wire speed, down feed rate, and wire bow angle in diamond wire saw machining are developed. The application of a capacitance sensor to measure the wire bow and a procedure to convert the wire bow to vertical cutting force in a rocking motion wire saw machine are developed. The tension force of the wire during cutting is also derived and discussed. [Copyright &y& Elsevier]

• A numerical model for analysis the fracture strength of silicon wafer is established. • The effects of process and wire parameters on wafer fracture strength are analyzed. • The relationship between the wafer fracture strength and the SSD is studied. The fracture strength of photovoltaic silicon wafers is affected by factors such as slicing process parameters and saw wire parameters. This paper numerically simulates the process of diamond wire sawing silicon crystals combined with the linear elastic fracture mechanics. A mathematical analysis model has been established to calculate the fracture strength of diamond wire cut silicon wafers in the light of the half-penny crack system. The effect of cutting conditions and saw wire conditions on wafers' fracture strength, and the relationship between wafers' fracture strength and subsurface micro-crack damage depth (SSD) were studied. The study results show that the numerical calculated values are equivalent to the experimental values of the reference, which proves the correctness of this model. It is found that the wire speed and the abrasive density are positively correlated with the wafers' fracture strength. The feed rate and the maximum size difference of the abrasives are inversely correlated with the wafers' fracture strength. When the ratio of wire speed to feed rate is constant, the wafers' fracture strength has no obvious change. And if the ratio becomes larger, the wafers' fracture strength will become larger. Besides, the wafers' fracture strength is not affected by the change in the abrasive size under the condition that the maximum size difference of abrasives remains unchanged and the wire inner diameter's change. The SSD is inversely correlated with the wafers' fracture strength. The study results of this paper can provide theoretical guidance for parameter optimization in the sawing process and reduction of wafer breakage probability. [ABSTRACT FROM AUTHOR]