摘要
采用真空烧结-渗碳处理工艺制备了梯度结构硬质合金,通过力学性能测试、物理性能测试和光学显微分析研究了渗碳处理前的真空烧结工艺和渗碳处理时间对合金抗弯强度、冲击韧性、密度、矫顽磁力以及表层双相区厚度的影响。结果表明:在渗碳的开始阶段,合金的抗弯强度、冲击韧性以及表面硬度均随渗碳时间的延长而增大;继续延长渗碳时间,合金的力学性能开始下降;合理控制渗碳时间以便得到适当厚度的WC+Co两相区是获得高性能梯度结构硬质合金的关键因素之一;在渗碳过程中,合金的矫顽磁力和密度随渗碳时间的增加而下降,表层WC+Co两相区的厚度随渗碳时间的增加而增加。
Cemented carbide with gradient structure was fabricated by vacuum sintering-carburizing process successfully.By using mechanical properties tests,physical properties tests and metallographical microscope analyses,the influence of vacuum sintering process before carburizing and carburizing time on transverse rupture strength,impact toughness,density,coersive force and the thickness of gradient structure with WC+Co phases were extensively investigated.The results show that the transverse rupture strength,impact toughness and surface hardness increase with carbusintering time at the beginning of the carbusintering process,and then decrease with carbusintering time,this could be attributed to the too narrow width of WC+Co+η phases zone;modest thickness of gradient structure is one of the crucial factors to obtain high performance of graded cemented carbide;coersive force and density of the alloy decrease with the increasing of carburizing time,while the thickness of gradient structure zone of WC+Co phases increases with increasing of the carburizing time.
出处
《粉末冶金材料科学与工程》
EI
2005年第6期356-360,共5页
Materials Science and Engineering of Powder Metallurgy
基金
国家自然科学基金资助项目(50323008)
