The Experts below are selected from a list of 6249 Experts worldwide ranked by ideXlab platform
Zhiqiang Liang - One of the best experts on this subject based on the ideXlab platform.
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experimental study on brittle ductile transition in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire using single diamond abrasive grain
International Journal of Machine Tools & Manufacture, 2013Co-Authors: Zhiqiang Liang, Xibin Wang, Yongbo Wu, Li Jiao, Wenxiang ZhaoAbstract:Abstract This study is carried out to investigate the material removal characteristics in elliptical ultrasonic assisted Grinding (EUAG) of monocrystal sapphire using single diamond abrasive grain. The scratching experiments are performed to develop a fundamental understanding of the ductile–brittle transition mechanism during EUAG of monocrystal sapphire. An elliptical ultrasonic vibrator attached with a sapphire substrate was set up on a multi-axis CNC controlled machining center equipped with a single point diamond tool. The vibrator was constructed by bonding a piezoelectric ceramic device (PZT) having two separated electrodes on a metal elastic body, and an elliptical ultrasonic vibration was generated on the end-face of the metal elastic body when two phases of alternating current (AC) voltages with a phase difference are applied to their respective electrodes on PZT. In scratching experiments, the effects of ultrasonic vibration on the critical depth of cut a c for the ductile–brittle transition region and the material removal ratio, i.e., the ratio of the removed material volume to the machined groove volume, f ab , are investigated by the examination of the scratching groove surfaces with SEM and AFM. The obtained results show that the critical depth of cut in EUAG is much larger than that in Conventional Grinding without vibration (CG), and even the bigger vibration amplitude leads to a greater improvement. Although the values of f ab in the ductile–brittle transition region in both EUAG and CG are less than 1, that in EUAG is bigger than that in CG. Furthermore, as the vibration amplitude increases, the value of f ab is increased to eventually be close to 1. These show that it is prone to achieve a ductile mode Grinding in greater vibration amplitude. It was also found that in the process there are two kinds of material removal modes, i.e., continuous cutting and discontinuous cutting modes, which are determined by the relationship between values of vibration amplitude and depth of cut. This study validates that the elliptical ultrasonic assisted Grinding method is highly effective in ductile mode machining of hard and brittle materials.
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experimental study on brittle ductile transition in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire using single diamond abrasive grain
International Journal of Machine Tools & Manufacture, 2013Co-Authors: Zhiqiang Liang, Xibin Wang, Li Jiao, Lijing Xie, Wenxiang ZhaoAbstract:Abstract This study is carried out to investigate the material removal characteristics in elliptical ultrasonic assisted Grinding (EUAG) of monocrystal sapphire using single diamond abrasive grain. The scratching experiments are performed to develop a fundamental understanding of the ductile–brittle transition mechanism during EUAG of monocrystal sapphire. An elliptical ultrasonic vibrator attached with a sapphire substrate was set up on a multi-axis CNC controlled machining center equipped with a single point diamond tool. The vibrator was constructed by bonding a piezoelectric ceramic device (PZT) having two separated electrodes on a metal elastic body, and an elliptical ultrasonic vibration was generated on the end-face of the metal elastic body when two phases of alternating current (AC) voltages with a phase difference are applied to their respective electrodes on PZT. In scratching experiments, the effects of ultrasonic vibration on the critical depth of cut a c for the ductile–brittle transition region and the material removal ratio, i.e., the ratio of the removed material volume to the machined groove volume, f ab , are investigated by the examination of the scratching groove surfaces with SEM and AFM. The obtained results show that the critical depth of cut in EUAG is much larger than that in Conventional Grinding without vibration (CG), and even the bigger vibration amplitude leads to a greater improvement. Although the values of f ab in the ductile–brittle transition region in both EUAG and CG are less than 1, that in EUAG is bigger than that in CG. Furthermore, as the vibration amplitude increases, the value of f ab is increased to eventually be close to 1. These show that it is prone to achieve a ductile mode Grinding in greater vibration amplitude. It was also found that in the process there are two kinds of material removal modes, i.e., continuous cutting and discontinuous cutting modes, which are determined by the relationship between values of vibration amplitude and depth of cut. This study validates that the elliptical ultrasonic assisted Grinding method is highly effective in ductile mode machining of hard and brittle materials.
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an investigation on wear mechanism of resin bonded diamond wheel in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire
Journal of Materials Processing Technology, 2012Co-Authors: Zhiqiang Liang, Xibin Wang, Lijing Xie, Zhibing Liu, Wenxiang ZhaoAbstract:Abstract An investigation is carried out to analyze and quantify the wear mechanisms of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire. The EUAG is a new Grinding method proposed by the present authors in which an elliptical ultrasonic vibration is imposed on the workpiece by using an elliptical ultrasonic vibrator. In this paper, a series of Grinding experiments under the presence/absence of ultrasonic vibration assistance are performed. The Grinding forces and work-surface roughness are measured, and the wheel surface is examined too. The experimental results indicate that during Grinding, the steady process region performed in EUAG is longer than that in Conventional Grinding (CG) by 20%, meaning that the Grinding wheel has a longer sharp cutting period in EUAG. It is validated that the main wear mechanisms in EUAG is micro-fracture and cleavage of abrasive grains, which has a positive effect on the better Grinding performance, such as lower Grinding forces, force ratio Fn/Ft, wheel loading, and smoother work-surface. This study demonstrates that the improved Grinding performance of diamond wheel can be realized by using EUAG method.
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an investigation on wear mechanism of resin bonded diamond wheel in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire
Journal of Materials Processing Technology, 2012Co-Authors: Zhiqiang Liang, Xibin Wang, Yongbo Wu, Wenxiang ZhaoAbstract:Abstract An investigation is carried out to analyze and quantify the wear mechanisms of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire. The EUAG is a new Grinding method proposed by the present authors in which an elliptical ultrasonic vibration is imposed on the workpiece by using an elliptical ultrasonic vibrator. In this paper, a series of Grinding experiments under the presence/absence of ultrasonic vibration assistance are performed. The Grinding forces and work-surface roughness are measured, and the wheel surface is examined too. The experimental results indicate that during Grinding, the steady process region performed in EUAG is longer than that in Conventional Grinding (CG) by 20%, meaning that the Grinding wheel has a longer sharp cutting period in EUAG. It is validated that the main wear mechanisms in EUAG is micro-fracture and cleavage of abrasive grains, which has a positive effect on the better Grinding performance, such as lower Grinding forces, force ratio Fn/Ft, wheel loading, and smoother work-surface. This study demonstrates that the improved Grinding performance of diamond wheel can be realized by using EUAG method.
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a new two dimensional ultrasonic assisted Grinding 2d uag method and its fundamental performance in monocrystal silicon machining
International Journal of Machine Tools & Manufacture, 2010Co-Authors: Zhiqiang Liang, Xibin Wang, Wenxiang ZhaoAbstract:A new two-dimensional (i.e., elliptical) ultrasonic assisted Grinding (UAG) technique is proposed to achieve high material removal rate and high surface quality in the machining of hard and brittle materials such as monocrystal silicon. In this method, the workpiece attached on an elliptical ultrasonic vibrator is ground with a resin bond diamond Grinding wheel under the presence of elliptical ultrasonic vibration. The elliptical ultrasonic vibrator is produced by bonding a piezoelectric ceramic device (PZT) on a metal elastic body (stainless steel, SUS304) and its detailed structure/dimensions are determined by FEM (finite element method) analysis. When two alternating current voltages with a phase difference are applied to the PZT at the same frequency that is close to the resonant frequency of the longitudinal mode and bending mode of vibrator, two ultrasonic vibrations are generated simultaneously, and the synthesis of the vibrations results in an elliptical motion on the end face of the vibrator. If the phase difference is set at 0° or 180°, two kinds of one-dimensional ultrasonic vibrations, i.e., axial or vertical vibrations, can be obtained. Grinding experiments are carried out involving monocrystal silicon to confirm the performance of the proposed elliptical UAG. In addition, Grinding experiments under the presence of the axial and vertical ultrasonic vibrations and the absence of ultrasonic vibrations, i.e., Conventional Grinding, are also carried out for comparison. The obtained results show that: (1) compared with Conventional Grinding, the axial ultrasonic vibration results in greatest improvement in the work surface quality and a slight reduction in the Grinding forces; (2) under the vertical ultrasonic vibration, the Grinding forces are decreased significantly but the surface roughness is increased slightly; (3) elliptical ultrasonic vibration leads to the significant reduction of both the surface roughness and Grinding forces. These indicate that the high efficiency and high-quality Grinding of monocrystal silicon can be performed with the proposed two-dimensional ultrasonic assisted Grinding technique.
Wenxiang Zhao - One of the best experts on this subject based on the ideXlab platform.
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experimental study on brittle ductile transition in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire using single diamond abrasive grain
International Journal of Machine Tools & Manufacture, 2013Co-Authors: Zhiqiang Liang, Xibin Wang, Yongbo Wu, Li Jiao, Wenxiang ZhaoAbstract:Abstract This study is carried out to investigate the material removal characteristics in elliptical ultrasonic assisted Grinding (EUAG) of monocrystal sapphire using single diamond abrasive grain. The scratching experiments are performed to develop a fundamental understanding of the ductile–brittle transition mechanism during EUAG of monocrystal sapphire. An elliptical ultrasonic vibrator attached with a sapphire substrate was set up on a multi-axis CNC controlled machining center equipped with a single point diamond tool. The vibrator was constructed by bonding a piezoelectric ceramic device (PZT) having two separated electrodes on a metal elastic body, and an elliptical ultrasonic vibration was generated on the end-face of the metal elastic body when two phases of alternating current (AC) voltages with a phase difference are applied to their respective electrodes on PZT. In scratching experiments, the effects of ultrasonic vibration on the critical depth of cut a c for the ductile–brittle transition region and the material removal ratio, i.e., the ratio of the removed material volume to the machined groove volume, f ab , are investigated by the examination of the scratching groove surfaces with SEM and AFM. The obtained results show that the critical depth of cut in EUAG is much larger than that in Conventional Grinding without vibration (CG), and even the bigger vibration amplitude leads to a greater improvement. Although the values of f ab in the ductile–brittle transition region in both EUAG and CG are less than 1, that in EUAG is bigger than that in CG. Furthermore, as the vibration amplitude increases, the value of f ab is increased to eventually be close to 1. These show that it is prone to achieve a ductile mode Grinding in greater vibration amplitude. It was also found that in the process there are two kinds of material removal modes, i.e., continuous cutting and discontinuous cutting modes, which are determined by the relationship between values of vibration amplitude and depth of cut. This study validates that the elliptical ultrasonic assisted Grinding method is highly effective in ductile mode machining of hard and brittle materials.
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experimental study on brittle ductile transition in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire using single diamond abrasive grain
International Journal of Machine Tools & Manufacture, 2013Co-Authors: Zhiqiang Liang, Xibin Wang, Li Jiao, Lijing Xie, Wenxiang ZhaoAbstract:Abstract This study is carried out to investigate the material removal characteristics in elliptical ultrasonic assisted Grinding (EUAG) of monocrystal sapphire using single diamond abrasive grain. The scratching experiments are performed to develop a fundamental understanding of the ductile–brittle transition mechanism during EUAG of monocrystal sapphire. An elliptical ultrasonic vibrator attached with a sapphire substrate was set up on a multi-axis CNC controlled machining center equipped with a single point diamond tool. The vibrator was constructed by bonding a piezoelectric ceramic device (PZT) having two separated electrodes on a metal elastic body, and an elliptical ultrasonic vibration was generated on the end-face of the metal elastic body when two phases of alternating current (AC) voltages with a phase difference are applied to their respective electrodes on PZT. In scratching experiments, the effects of ultrasonic vibration on the critical depth of cut a c for the ductile–brittle transition region and the material removal ratio, i.e., the ratio of the removed material volume to the machined groove volume, f ab , are investigated by the examination of the scratching groove surfaces with SEM and AFM. The obtained results show that the critical depth of cut in EUAG is much larger than that in Conventional Grinding without vibration (CG), and even the bigger vibration amplitude leads to a greater improvement. Although the values of f ab in the ductile–brittle transition region in both EUAG and CG are less than 1, that in EUAG is bigger than that in CG. Furthermore, as the vibration amplitude increases, the value of f ab is increased to eventually be close to 1. These show that it is prone to achieve a ductile mode Grinding in greater vibration amplitude. It was also found that in the process there are two kinds of material removal modes, i.e., continuous cutting and discontinuous cutting modes, which are determined by the relationship between values of vibration amplitude and depth of cut. This study validates that the elliptical ultrasonic assisted Grinding method is highly effective in ductile mode machining of hard and brittle materials.
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an investigation on wear mechanism of resin bonded diamond wheel in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire
Journal of Materials Processing Technology, 2012Co-Authors: Zhiqiang Liang, Xibin Wang, Lijing Xie, Zhibing Liu, Wenxiang ZhaoAbstract:Abstract An investigation is carried out to analyze and quantify the wear mechanisms of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire. The EUAG is a new Grinding method proposed by the present authors in which an elliptical ultrasonic vibration is imposed on the workpiece by using an elliptical ultrasonic vibrator. In this paper, a series of Grinding experiments under the presence/absence of ultrasonic vibration assistance are performed. The Grinding forces and work-surface roughness are measured, and the wheel surface is examined too. The experimental results indicate that during Grinding, the steady process region performed in EUAG is longer than that in Conventional Grinding (CG) by 20%, meaning that the Grinding wheel has a longer sharp cutting period in EUAG. It is validated that the main wear mechanisms in EUAG is micro-fracture and cleavage of abrasive grains, which has a positive effect on the better Grinding performance, such as lower Grinding forces, force ratio Fn/Ft, wheel loading, and smoother work-surface. This study demonstrates that the improved Grinding performance of diamond wheel can be realized by using EUAG method.
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an investigation on wear mechanism of resin bonded diamond wheel in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire
Journal of Materials Processing Technology, 2012Co-Authors: Zhiqiang Liang, Xibin Wang, Yongbo Wu, Wenxiang ZhaoAbstract:Abstract An investigation is carried out to analyze and quantify the wear mechanisms of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire. The EUAG is a new Grinding method proposed by the present authors in which an elliptical ultrasonic vibration is imposed on the workpiece by using an elliptical ultrasonic vibrator. In this paper, a series of Grinding experiments under the presence/absence of ultrasonic vibration assistance are performed. The Grinding forces and work-surface roughness are measured, and the wheel surface is examined too. The experimental results indicate that during Grinding, the steady process region performed in EUAG is longer than that in Conventional Grinding (CG) by 20%, meaning that the Grinding wheel has a longer sharp cutting period in EUAG. It is validated that the main wear mechanisms in EUAG is micro-fracture and cleavage of abrasive grains, which has a positive effect on the better Grinding performance, such as lower Grinding forces, force ratio Fn/Ft, wheel loading, and smoother work-surface. This study demonstrates that the improved Grinding performance of diamond wheel can be realized by using EUAG method.
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a new two dimensional ultrasonic assisted Grinding 2d uag method and its fundamental performance in monocrystal silicon machining
International Journal of Machine Tools & Manufacture, 2010Co-Authors: Zhiqiang Liang, Xibin Wang, Wenxiang ZhaoAbstract:A new two-dimensional (i.e., elliptical) ultrasonic assisted Grinding (UAG) technique is proposed to achieve high material removal rate and high surface quality in the machining of hard and brittle materials such as monocrystal silicon. In this method, the workpiece attached on an elliptical ultrasonic vibrator is ground with a resin bond diamond Grinding wheel under the presence of elliptical ultrasonic vibration. The elliptical ultrasonic vibrator is produced by bonding a piezoelectric ceramic device (PZT) on a metal elastic body (stainless steel, SUS304) and its detailed structure/dimensions are determined by FEM (finite element method) analysis. When two alternating current voltages with a phase difference are applied to the PZT at the same frequency that is close to the resonant frequency of the longitudinal mode and bending mode of vibrator, two ultrasonic vibrations are generated simultaneously, and the synthesis of the vibrations results in an elliptical motion on the end face of the vibrator. If the phase difference is set at 0° or 180°, two kinds of one-dimensional ultrasonic vibrations, i.e., axial or vertical vibrations, can be obtained. Grinding experiments are carried out involving monocrystal silicon to confirm the performance of the proposed elliptical UAG. In addition, Grinding experiments under the presence of the axial and vertical ultrasonic vibrations and the absence of ultrasonic vibrations, i.e., Conventional Grinding, are also carried out for comparison. The obtained results show that: (1) compared with Conventional Grinding, the axial ultrasonic vibration results in greatest improvement in the work surface quality and a slight reduction in the Grinding forces; (2) under the vertical ultrasonic vibration, the Grinding forces are decreased significantly but the surface roughness is increased slightly; (3) elliptical ultrasonic vibration leads to the significant reduction of both the surface roughness and Grinding forces. These indicate that the high efficiency and high-quality Grinding of monocrystal silicon can be performed with the proposed two-dimensional ultrasonic assisted Grinding technique.
Xibin Wang - One of the best experts on this subject based on the ideXlab platform.
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experimental study on brittle ductile transition in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire using single diamond abrasive grain
International Journal of Machine Tools & Manufacture, 2013Co-Authors: Zhiqiang Liang, Xibin Wang, Yongbo Wu, Li Jiao, Wenxiang ZhaoAbstract:Abstract This study is carried out to investigate the material removal characteristics in elliptical ultrasonic assisted Grinding (EUAG) of monocrystal sapphire using single diamond abrasive grain. The scratching experiments are performed to develop a fundamental understanding of the ductile–brittle transition mechanism during EUAG of monocrystal sapphire. An elliptical ultrasonic vibrator attached with a sapphire substrate was set up on a multi-axis CNC controlled machining center equipped with a single point diamond tool. The vibrator was constructed by bonding a piezoelectric ceramic device (PZT) having two separated electrodes on a metal elastic body, and an elliptical ultrasonic vibration was generated on the end-face of the metal elastic body when two phases of alternating current (AC) voltages with a phase difference are applied to their respective electrodes on PZT. In scratching experiments, the effects of ultrasonic vibration on the critical depth of cut a c for the ductile–brittle transition region and the material removal ratio, i.e., the ratio of the removed material volume to the machined groove volume, f ab , are investigated by the examination of the scratching groove surfaces with SEM and AFM. The obtained results show that the critical depth of cut in EUAG is much larger than that in Conventional Grinding without vibration (CG), and even the bigger vibration amplitude leads to a greater improvement. Although the values of f ab in the ductile–brittle transition region in both EUAG and CG are less than 1, that in EUAG is bigger than that in CG. Furthermore, as the vibration amplitude increases, the value of f ab is increased to eventually be close to 1. These show that it is prone to achieve a ductile mode Grinding in greater vibration amplitude. It was also found that in the process there are two kinds of material removal modes, i.e., continuous cutting and discontinuous cutting modes, which are determined by the relationship between values of vibration amplitude and depth of cut. This study validates that the elliptical ultrasonic assisted Grinding method is highly effective in ductile mode machining of hard and brittle materials.
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experimental study on brittle ductile transition in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire using single diamond abrasive grain
International Journal of Machine Tools & Manufacture, 2013Co-Authors: Zhiqiang Liang, Xibin Wang, Li Jiao, Lijing Xie, Wenxiang ZhaoAbstract:Abstract This study is carried out to investigate the material removal characteristics in elliptical ultrasonic assisted Grinding (EUAG) of monocrystal sapphire using single diamond abrasive grain. The scratching experiments are performed to develop a fundamental understanding of the ductile–brittle transition mechanism during EUAG of monocrystal sapphire. An elliptical ultrasonic vibrator attached with a sapphire substrate was set up on a multi-axis CNC controlled machining center equipped with a single point diamond tool. The vibrator was constructed by bonding a piezoelectric ceramic device (PZT) having two separated electrodes on a metal elastic body, and an elliptical ultrasonic vibration was generated on the end-face of the metal elastic body when two phases of alternating current (AC) voltages with a phase difference are applied to their respective electrodes on PZT. In scratching experiments, the effects of ultrasonic vibration on the critical depth of cut a c for the ductile–brittle transition region and the material removal ratio, i.e., the ratio of the removed material volume to the machined groove volume, f ab , are investigated by the examination of the scratching groove surfaces with SEM and AFM. The obtained results show that the critical depth of cut in EUAG is much larger than that in Conventional Grinding without vibration (CG), and even the bigger vibration amplitude leads to a greater improvement. Although the values of f ab in the ductile–brittle transition region in both EUAG and CG are less than 1, that in EUAG is bigger than that in CG. Furthermore, as the vibration amplitude increases, the value of f ab is increased to eventually be close to 1. These show that it is prone to achieve a ductile mode Grinding in greater vibration amplitude. It was also found that in the process there are two kinds of material removal modes, i.e., continuous cutting and discontinuous cutting modes, which are determined by the relationship between values of vibration amplitude and depth of cut. This study validates that the elliptical ultrasonic assisted Grinding method is highly effective in ductile mode machining of hard and brittle materials.
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an investigation on wear mechanism of resin bonded diamond wheel in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire
Journal of Materials Processing Technology, 2012Co-Authors: Zhiqiang Liang, Xibin Wang, Lijing Xie, Zhibing Liu, Wenxiang ZhaoAbstract:Abstract An investigation is carried out to analyze and quantify the wear mechanisms of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire. The EUAG is a new Grinding method proposed by the present authors in which an elliptical ultrasonic vibration is imposed on the workpiece by using an elliptical ultrasonic vibrator. In this paper, a series of Grinding experiments under the presence/absence of ultrasonic vibration assistance are performed. The Grinding forces and work-surface roughness are measured, and the wheel surface is examined too. The experimental results indicate that during Grinding, the steady process region performed in EUAG is longer than that in Conventional Grinding (CG) by 20%, meaning that the Grinding wheel has a longer sharp cutting period in EUAG. It is validated that the main wear mechanisms in EUAG is micro-fracture and cleavage of abrasive grains, which has a positive effect on the better Grinding performance, such as lower Grinding forces, force ratio Fn/Ft, wheel loading, and smoother work-surface. This study demonstrates that the improved Grinding performance of diamond wheel can be realized by using EUAG method.
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an investigation on wear mechanism of resin bonded diamond wheel in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire
Journal of Materials Processing Technology, 2012Co-Authors: Zhiqiang Liang, Xibin Wang, Yongbo Wu, Wenxiang ZhaoAbstract:Abstract An investigation is carried out to analyze and quantify the wear mechanisms of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire. The EUAG is a new Grinding method proposed by the present authors in which an elliptical ultrasonic vibration is imposed on the workpiece by using an elliptical ultrasonic vibrator. In this paper, a series of Grinding experiments under the presence/absence of ultrasonic vibration assistance are performed. The Grinding forces and work-surface roughness are measured, and the wheel surface is examined too. The experimental results indicate that during Grinding, the steady process region performed in EUAG is longer than that in Conventional Grinding (CG) by 20%, meaning that the Grinding wheel has a longer sharp cutting period in EUAG. It is validated that the main wear mechanisms in EUAG is micro-fracture and cleavage of abrasive grains, which has a positive effect on the better Grinding performance, such as lower Grinding forces, force ratio Fn/Ft, wheel loading, and smoother work-surface. This study demonstrates that the improved Grinding performance of diamond wheel can be realized by using EUAG method.
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a new two dimensional ultrasonic assisted Grinding 2d uag method and its fundamental performance in monocrystal silicon machining
International Journal of Machine Tools & Manufacture, 2010Co-Authors: Zhiqiang Liang, Xibin Wang, Wenxiang ZhaoAbstract:A new two-dimensional (i.e., elliptical) ultrasonic assisted Grinding (UAG) technique is proposed to achieve high material removal rate and high surface quality in the machining of hard and brittle materials such as monocrystal silicon. In this method, the workpiece attached on an elliptical ultrasonic vibrator is ground with a resin bond diamond Grinding wheel under the presence of elliptical ultrasonic vibration. The elliptical ultrasonic vibrator is produced by bonding a piezoelectric ceramic device (PZT) on a metal elastic body (stainless steel, SUS304) and its detailed structure/dimensions are determined by FEM (finite element method) analysis. When two alternating current voltages with a phase difference are applied to the PZT at the same frequency that is close to the resonant frequency of the longitudinal mode and bending mode of vibrator, two ultrasonic vibrations are generated simultaneously, and the synthesis of the vibrations results in an elliptical motion on the end face of the vibrator. If the phase difference is set at 0° or 180°, two kinds of one-dimensional ultrasonic vibrations, i.e., axial or vertical vibrations, can be obtained. Grinding experiments are carried out involving monocrystal silicon to confirm the performance of the proposed elliptical UAG. In addition, Grinding experiments under the presence of the axial and vertical ultrasonic vibrations and the absence of ultrasonic vibrations, i.e., Conventional Grinding, are also carried out for comparison. The obtained results show that: (1) compared with Conventional Grinding, the axial ultrasonic vibration results in greatest improvement in the work surface quality and a slight reduction in the Grinding forces; (2) under the vertical ultrasonic vibration, the Grinding forces are decreased significantly but the surface roughness is increased slightly; (3) elliptical ultrasonic vibration leads to the significant reduction of both the surface roughness and Grinding forces. These indicate that the high efficiency and high-quality Grinding of monocrystal silicon can be performed with the proposed two-dimensional ultrasonic assisted Grinding technique.
Yongbo Wu - One of the best experts on this subject based on the ideXlab platform.
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experimental study on brittle ductile transition in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire using single diamond abrasive grain
International Journal of Machine Tools & Manufacture, 2013Co-Authors: Zhiqiang Liang, Xibin Wang, Yongbo Wu, Li Jiao, Wenxiang ZhaoAbstract:Abstract This study is carried out to investigate the material removal characteristics in elliptical ultrasonic assisted Grinding (EUAG) of monocrystal sapphire using single diamond abrasive grain. The scratching experiments are performed to develop a fundamental understanding of the ductile–brittle transition mechanism during EUAG of monocrystal sapphire. An elliptical ultrasonic vibrator attached with a sapphire substrate was set up on a multi-axis CNC controlled machining center equipped with a single point diamond tool. The vibrator was constructed by bonding a piezoelectric ceramic device (PZT) having two separated electrodes on a metal elastic body, and an elliptical ultrasonic vibration was generated on the end-face of the metal elastic body when two phases of alternating current (AC) voltages with a phase difference are applied to their respective electrodes on PZT. In scratching experiments, the effects of ultrasonic vibration on the critical depth of cut a c for the ductile–brittle transition region and the material removal ratio, i.e., the ratio of the removed material volume to the machined groove volume, f ab , are investigated by the examination of the scratching groove surfaces with SEM and AFM. The obtained results show that the critical depth of cut in EUAG is much larger than that in Conventional Grinding without vibration (CG), and even the bigger vibration amplitude leads to a greater improvement. Although the values of f ab in the ductile–brittle transition region in both EUAG and CG are less than 1, that in EUAG is bigger than that in CG. Furthermore, as the vibration amplitude increases, the value of f ab is increased to eventually be close to 1. These show that it is prone to achieve a ductile mode Grinding in greater vibration amplitude. It was also found that in the process there are two kinds of material removal modes, i.e., continuous cutting and discontinuous cutting modes, which are determined by the relationship between values of vibration amplitude and depth of cut. This study validates that the elliptical ultrasonic assisted Grinding method is highly effective in ductile mode machining of hard and brittle materials.
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an investigation on wear mechanism of resin bonded diamond wheel in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire
Journal of Materials Processing Technology, 2012Co-Authors: Zhiqiang Liang, Xibin Wang, Yongbo Wu, Wenxiang ZhaoAbstract:Abstract An investigation is carried out to analyze and quantify the wear mechanisms of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire. The EUAG is a new Grinding method proposed by the present authors in which an elliptical ultrasonic vibration is imposed on the workpiece by using an elliptical ultrasonic vibrator. In this paper, a series of Grinding experiments under the presence/absence of ultrasonic vibration assistance are performed. The Grinding forces and work-surface roughness are measured, and the wheel surface is examined too. The experimental results indicate that during Grinding, the steady process region performed in EUAG is longer than that in Conventional Grinding (CG) by 20%, meaning that the Grinding wheel has a longer sharp cutting period in EUAG. It is validated that the main wear mechanisms in EUAG is micro-fracture and cleavage of abrasive grains, which has a positive effect on the better Grinding performance, such as lower Grinding forces, force ratio Fn/Ft, wheel loading, and smoother work-surface. This study demonstrates that the improved Grinding performance of diamond wheel can be realized by using EUAG method.
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a new two dimensional ultrasonic assisted Grinding 2d uag method and its fundamental performance in monocrystal silicon machining
International Journal of Machine Tools & Manufacture, 2010Co-Authors: Zhiqiang Liang, Xibin Wang, Yongbo Wu, Wenxiang ZhaoAbstract:A new two-dimensional (i.e., elliptical) ultrasonic assisted Grinding (UAG) technique is proposed to achieve high material removal rate and high surface quality in the machining of hard and brittle materials such as monocrystal silicon. In this method, the workpiece attached on an elliptical ultrasonic vibrator is ground with a resin bond diamond Grinding wheel under the presence of elliptical ultrasonic vibration. The elliptical ultrasonic vibrator is produced by bonding a piezoelectric ceramic device (PZT) on a metal elastic body (stainless steel, SUS304) and its detailed structure/dimensions are determined by FEM (finite element method) analysis. When two alternating current voltages with a phase difference are applied to the PZT at the same frequency that is close to the resonant frequency of the longitudinal mode and bending mode of vibrator, two ultrasonic vibrations are generated simultaneously, and the synthesis of the vibrations results in an elliptical motion on the end face of the vibrator. If the phase difference is set at 0° or 180°, two kinds of one-dimensional ultrasonic vibrations, i.e., axial or vertical vibrations, can be obtained. Grinding experiments are carried out involving monocrystal silicon to confirm the performance of the proposed elliptical UAG. In addition, Grinding experiments under the presence of the axial and vertical ultrasonic vibrations and the absence of ultrasonic vibrations, i.e., Conventional Grinding, are also carried out for comparison. The obtained results show that: (1) compared with Conventional Grinding, the axial ultrasonic vibration results in greatest improvement in the work surface quality and a slight reduction in the Grinding forces; (2) under the vertical ultrasonic vibration, the Grinding forces are decreased significantly but the surface roughness is increased slightly; (3) elliptical ultrasonic vibration leads to the significant reduction of both the surface roughness and Grinding forces. These indicate that the high efficiency and high-quality Grinding of monocrystal silicon can be performed with the proposed two-dimensional ultrasonic assisted Grinding technique.
Lijing Xie - One of the best experts on this subject based on the ideXlab platform.
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experimental study on brittle ductile transition in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire using single diamond abrasive grain
International Journal of Machine Tools & Manufacture, 2013Co-Authors: Zhiqiang Liang, Xibin Wang, Li Jiao, Lijing Xie, Wenxiang ZhaoAbstract:Abstract This study is carried out to investigate the material removal characteristics in elliptical ultrasonic assisted Grinding (EUAG) of monocrystal sapphire using single diamond abrasive grain. The scratching experiments are performed to develop a fundamental understanding of the ductile–brittle transition mechanism during EUAG of monocrystal sapphire. An elliptical ultrasonic vibrator attached with a sapphire substrate was set up on a multi-axis CNC controlled machining center equipped with a single point diamond tool. The vibrator was constructed by bonding a piezoelectric ceramic device (PZT) having two separated electrodes on a metal elastic body, and an elliptical ultrasonic vibration was generated on the end-face of the metal elastic body when two phases of alternating current (AC) voltages with a phase difference are applied to their respective electrodes on PZT. In scratching experiments, the effects of ultrasonic vibration on the critical depth of cut a c for the ductile–brittle transition region and the material removal ratio, i.e., the ratio of the removed material volume to the machined groove volume, f ab , are investigated by the examination of the scratching groove surfaces with SEM and AFM. The obtained results show that the critical depth of cut in EUAG is much larger than that in Conventional Grinding without vibration (CG), and even the bigger vibration amplitude leads to a greater improvement. Although the values of f ab in the ductile–brittle transition region in both EUAG and CG are less than 1, that in EUAG is bigger than that in CG. Furthermore, as the vibration amplitude increases, the value of f ab is increased to eventually be close to 1. These show that it is prone to achieve a ductile mode Grinding in greater vibration amplitude. It was also found that in the process there are two kinds of material removal modes, i.e., continuous cutting and discontinuous cutting modes, which are determined by the relationship between values of vibration amplitude and depth of cut. This study validates that the elliptical ultrasonic assisted Grinding method is highly effective in ductile mode machining of hard and brittle materials.
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an investigation on wear mechanism of resin bonded diamond wheel in elliptical ultrasonic assisted Grinding euag of monocrystal sapphire
Journal of Materials Processing Technology, 2012Co-Authors: Zhiqiang Liang, Xibin Wang, Lijing Xie, Zhibing Liu, Wenxiang ZhaoAbstract:Abstract An investigation is carried out to analyze and quantify the wear mechanisms of resin-bonded diamond wheel in Elliptical Ultrasonic Assisted Grinding (EUAG) of monocrystal sapphire. The EUAG is a new Grinding method proposed by the present authors in which an elliptical ultrasonic vibration is imposed on the workpiece by using an elliptical ultrasonic vibrator. In this paper, a series of Grinding experiments under the presence/absence of ultrasonic vibration assistance are performed. The Grinding forces and work-surface roughness are measured, and the wheel surface is examined too. The experimental results indicate that during Grinding, the steady process region performed in EUAG is longer than that in Conventional Grinding (CG) by 20%, meaning that the Grinding wheel has a longer sharp cutting period in EUAG. It is validated that the main wear mechanisms in EUAG is micro-fracture and cleavage of abrasive grains, which has a positive effect on the better Grinding performance, such as lower Grinding forces, force ratio Fn/Ft, wheel loading, and smoother work-surface. This study demonstrates that the improved Grinding performance of diamond wheel can be realized by using EUAG method.