粉末冶金表面滚压致密化链轮工艺的开发

Process development of surface rolling densification powder metallurgy sprockets

粉末冶金零件以其近终成形、成本低、效率高的优势在汽车行业得到了广泛的应用。但是由于粉末冶金零件表面存在大量的空隙,严重影响了其强度、硬度和耐磨性等性能,使其在某些重载工况中达不到要求,从而限制了其在汽车行业的应用。本文论述了一种粉末冶滚压金表面致密化链轮工艺,通过将粉末冶金技术和滚压致密化技术结合在一起,减小粉末冶金零件表面的空隙,在零件表面形成一层均匀的致密层,而提高其强度、硬度和耐磨性等性能,从而扩大其应用范围。

The powder metallurgy （PM） parts have been widely used in automobile industry because of the advantages of net shape capability, low cost and high efficiency in production. However, due to the high initial porosity, which significantly reduces the strength of material, sintered metals cannot be used for the highly loaded mechanical parts. In this study, through combining the powder metallurgy process and rolling process, the pore in the PM components were decreased and a homogenous densified layer was formed on the surface, which results in the enhancement of the strength, hardness, wear resistance and other properties, which can expand its range of application.