Five kinds of 45# steel samples with concave features on the surface were manufactured using Laser Texturing Technology (LTT). Optimum design theory was used to design the experiment, and a two-level orthogonal table-...Five kinds of 45# steel samples with concave features on the surface were manufactured using Laser Texturing Technology (LTT). Optimum design theory was used to design the experiment, and a two-level orthogonal table-L 16 (2 15 ) design was adopted . Micro-wear and micro-friction experienced by samples with concave surface features and samples with smooth surfaces were compared experimentally. The wear resistance of samples with concave surface features was increased most, and different surface morphologies had different effects on friction and wear properties.展开更多
The wear and corrosion resistances are important in marine applications, especially when it comes to structural support components like bearings, bushes and blocks. The copper hybrid metal matrix components are the ne...The wear and corrosion resistances are important in marine applications, especially when it comes to structural support components like bearings, bushes and blocks. The copper hybrid metal matrix components are the new avenues explored in this front. A novel combination of alumina and graphite were considered as the reinforcements in a copper base for the development of a metal matrix composite.Power metallurgical techniques were used for the development of the MMC. The Vickers' s hardness value of 64.9 Hv has been observed by increasing the volume of alumina. Thermogravimetric analyses were carried out on material samples to estimate the exact sintering temperature and identified that 450-700℃ would be conducive. The TGA curves shows two step decomposition exists between 430 ℃-460 ℃. FT-IR analysis was done to confirm the peak values of the materials. FTIR exposed the peak value of 1600 cm^(-1) for alumina where as for Copper and graphite peak values have been 2840 cm^(-1) and 17260 cm^(-1) respectively. The potentio dynamic analysis was done to estimate the rate of corrosion on the samples. The sample with nano and micro reinforcements offered intensive resistance to corrosion. The presence of graphite minimized the weight loss of the samples during the corrosion test. Finally the wear rates of the samples were estimated using the Pin On Disc experimental setup. The samples with nano material reinforcement and with a maximum proportion of graphite exhibited a better wear rate of 1.52×10^(-12) m^2/kg under maximum load conditions.展开更多
The applications of micro machining have increased drastically in the last ten years. However, tools with less than lmm diameter using for micro-mills have very short and unpredictable life when they are used to cut h...The applications of micro machining have increased drastically in the last ten years. However, tools with less than lmm diameter using for micro-mills have very short and unpredictable life when they are used to cut hard metals. In this study, preliminary design of experiment （DOE） test program was conducted to investigate and i- dentify the factors affecting tool wear at the micro-scale with hard material. Analysis of variance （ANOVA） and Taguchi method were efficient to determine appropriate cutting condition and the effect of parameters. A simple model was also developed to predict the width of slots on the workpiece along the cutting length. The obtained re- suits can provide the basic guidelines for parameter setting of micro-end-milling with hard material.展开更多
The wear behavior of titanium silicon carbide MAX phase was investigated.Samples of highly pure TiSiCand containing 8% of TiC,sliding dryly against Corundum counterpart,were tested at various speeds increasing from 5 ...The wear behavior of titanium silicon carbide MAX phase was investigated.Samples of highly pure TiSiCand containing 8% of TiC,sliding dryly against Corundum counterpart,were tested at various speeds increasing from 5 to 60 m/s and under applied pressure of 0.1-0.8 MPa.The sliding-wear tests were performed on Tribometer,at room temperature of 15℃ with a relative humidity of 10%.The expermental results show that the presence of TiC particles can be beneficial to reducing the wear rate for certain ranges of sliding speed and applied pressure.The sliding-wear performances were expressed as a mathematical model,obtained through a modelling by the method of design of experiment.The influence of TiC impurities on the wear behaviors was also investigated.It is concluded that the wear mechanisms of samples are more affected by the presence of TiC under the effect of applied pressure compared with that of the sliding speed.展开更多
基金The authors are grateful for the financial support provided by the National High Technology Research and Development Program of China(863 Program)(No.2002AA331180)Trans-Century Training Program Foundation for the Talents by the Chinese Ministry of Education(No.20030720)+1 种基金the Foundation for Distin-guished Young Scholars of Jilin Province(Grant No.20040104)the Natural Science Foundation of Jilin Province(No.2002628-2).
文摘Five kinds of 45# steel samples with concave features on the surface were manufactured using Laser Texturing Technology (LTT). Optimum design theory was used to design the experiment, and a two-level orthogonal table-L 16 (2 15 ) design was adopted . Micro-wear and micro-friction experienced by samples with concave surface features and samples with smooth surfaces were compared experimentally. The wear resistance of samples with concave surface features was increased most, and different surface morphologies had different effects on friction and wear properties.
文摘The wear and corrosion resistances are important in marine applications, especially when it comes to structural support components like bearings, bushes and blocks. The copper hybrid metal matrix components are the new avenues explored in this front. A novel combination of alumina and graphite were considered as the reinforcements in a copper base for the development of a metal matrix composite.Power metallurgical techniques were used for the development of the MMC. The Vickers' s hardness value of 64.9 Hv has been observed by increasing the volume of alumina. Thermogravimetric analyses were carried out on material samples to estimate the exact sintering temperature and identified that 450-700℃ would be conducive. The TGA curves shows two step decomposition exists between 430 ℃-460 ℃. FT-IR analysis was done to confirm the peak values of the materials. FTIR exposed the peak value of 1600 cm^(-1) for alumina where as for Copper and graphite peak values have been 2840 cm^(-1) and 17260 cm^(-1) respectively. The potentio dynamic analysis was done to estimate the rate of corrosion on the samples. The sample with nano and micro reinforcements offered intensive resistance to corrosion. The presence of graphite minimized the weight loss of the samples during the corrosion test. Finally the wear rates of the samples were estimated using the Pin On Disc experimental setup. The samples with nano material reinforcement and with a maximum proportion of graphite exhibited a better wear rate of 1.52×10^(-12) m^2/kg under maximum load conditions.
文摘The applications of micro machining have increased drastically in the last ten years. However, tools with less than lmm diameter using for micro-mills have very short and unpredictable life when they are used to cut hard metals. In this study, preliminary design of experiment （DOE） test program was conducted to investigate and i- dentify the factors affecting tool wear at the micro-scale with hard material. Analysis of variance （ANOVA） and Taguchi method were efficient to determine appropriate cutting condition and the effect of parameters. A simple model was also developed to predict the width of slots on the workpiece along the cutting length. The obtained re- suits can provide the basic guidelines for parameter setting of micro-end-milling with hard material.
基金Funded by the Laboratory of Industrial Engineering and Sustainable Development,University of Relizane,Algeria。
文摘The wear behavior of titanium silicon carbide MAX phase was investigated.Samples of highly pure TiSiCand containing 8% of TiC,sliding dryly against Corundum counterpart,were tested at various speeds increasing from 5 to 60 m/s and under applied pressure of 0.1-0.8 MPa.The sliding-wear tests were performed on Tribometer,at room temperature of 15℃ with a relative humidity of 10%.The expermental results show that the presence of TiC particles can be beneficial to reducing the wear rate for certain ranges of sliding speed and applied pressure.The sliding-wear performances were expressed as a mathematical model,obtained through a modelling by the method of design of experiment.The influence of TiC impurities on the wear behaviors was also investigated.It is concluded that the wear mechanisms of samples are more affected by the presence of TiC under the effect of applied pressure compared with that of the sliding speed.
