Tungsten carbide is a material that is very difficult to cut,mainly owing to its extreme wear resistance.Its high value of yield strength,accompanied by extreme brittleness,renders its machinability extremely poor,wit...Tungsten carbide is a material that is very difficult to cut,mainly owing to its extreme wear resistance.Its high value of yield strength,accompanied by extreme brittleness,renders its machinability extremely poor,with most tools failing.Even when cutting with tool materials of the highest quality,its mode of cutting is mainly brittle and marred by material cracking.The ductile mode of cutting is possible only at micro leveIs of depth of cut and feed rate.This study aims to investigate the possibility of milling the carbide material at a meso-scale using polycrystaline diamond(PCD)end mills.A series of end milling experiments were performed to study the effects of cutting speed,feed per tooth,and axial depth of cut on performance measures such as cutting forces,surface roughness,and tool wear.To characterize the wear of PCD tools,a new approach to measuring the level of damage sustained by the faces of the cutter's teeth is presented.Analyses of the experimental data show that the effects of all the cutting parameters on the three performance measures are significant.The major damage mode of the PCD end mills is.found to be the intermittent micro-chipping.The progress of tool damage saw a long,stable,and steady period sandwiched between two short,abrupt,and intermittent periods.Cutting forces and surface roughness are found to rise with increments in the three cutting parameters,although the latter shows signs of reduction during the initial increase in cutting speed only.The results of this study find that an acceptable surface quality(average roughness Ra<0.2μm)and tool life(cutting length L>600mm)can be obtained under the conditions of the given cutting parameters.It indicates that milling with PCD tools at a meso-scale is a suitable machining method for tungsten carbides.展开更多
目的设计合理的抛光工艺方案,获得平整的阵列光纤组件端面。方法采用单因素实验法研究抛光工艺参数对阵列光纤表面粗糙度与光纤凸起量的影响,利用光学表面轮廓仪与扫描电镜进行分析与观察。结果在抛光液磨粒质量分数为2%,抛光液流量为15...目的设计合理的抛光工艺方案,获得平整的阵列光纤组件端面。方法采用单因素实验法研究抛光工艺参数对阵列光纤表面粗糙度与光纤凸起量的影响,利用光学表面轮廓仪与扫描电镜进行分析与观察。结果在抛光液磨粒质量分数为2%,抛光液流量为15 m L/min,抛光压力为50 k Pa,抛光盘转速为30 r/min的条件下,可以获得平整的阵列光纤组件端面。结论应用化学机械抛光技术加工阵列光纤组件,并设计合理工艺方案,可获得平整的阵列光纤组件端面,其表面粗糙度可低至42.6 nm,光纤凸起值可低至0.14μm。展开更多
基金supports by the National Natural Science Foundation of China(Grant Nos.51975289,51475234).
文摘Tungsten carbide is a material that is very difficult to cut,mainly owing to its extreme wear resistance.Its high value of yield strength,accompanied by extreme brittleness,renders its machinability extremely poor,with most tools failing.Even when cutting with tool materials of the highest quality,its mode of cutting is mainly brittle and marred by material cracking.The ductile mode of cutting is possible only at micro leveIs of depth of cut and feed rate.This study aims to investigate the possibility of milling the carbide material at a meso-scale using polycrystaline diamond(PCD)end mills.A series of end milling experiments were performed to study the effects of cutting speed,feed per tooth,and axial depth of cut on performance measures such as cutting forces,surface roughness,and tool wear.To characterize the wear of PCD tools,a new approach to measuring the level of damage sustained by the faces of the cutter's teeth is presented.Analyses of the experimental data show that the effects of all the cutting parameters on the three performance measures are significant.The major damage mode of the PCD end mills is.found to be the intermittent micro-chipping.The progress of tool damage saw a long,stable,and steady period sandwiched between two short,abrupt,and intermittent periods.Cutting forces and surface roughness are found to rise with increments in the three cutting parameters,although the latter shows signs of reduction during the initial increase in cutting speed only.The results of this study find that an acceptable surface quality(average roughness Ra<0.2μm)and tool life(cutting length L>600mm)can be obtained under the conditions of the given cutting parameters.It indicates that milling with PCD tools at a meso-scale is a suitable machining method for tungsten carbides.
文摘目的设计合理的抛光工艺方案,获得平整的阵列光纤组件端面。方法采用单因素实验法研究抛光工艺参数对阵列光纤表面粗糙度与光纤凸起量的影响,利用光学表面轮廓仪与扫描电镜进行分析与观察。结果在抛光液磨粒质量分数为2%,抛光液流量为15 m L/min,抛光压力为50 k Pa,抛光盘转速为30 r/min的条件下,可以获得平整的阵列光纤组件端面。结论应用化学机械抛光技术加工阵列光纤组件,并设计合理工艺方案,可获得平整的阵列光纤组件端面,其表面粗糙度可低至42.6 nm,光纤凸起值可低至0.14μm。
