粉末冶金烧结硬化凸轮材料的摩擦磨损性能研究

Study on friction and wear properties of powder metallurgy sinter hardening cam material

本研究将铁基Fe-Cr-Mo-Cu-Si-P-C粉末冶金材料用于组合烧结式粉末冶金中空凸轮轴的凸轮制备,使用MR-H5型高速环块磨损实验机进行摩擦磨损性能测试,并通过白光干涉形貌法对该凸轮材料在不同转速下的摩擦磨损性能进行研究。结果表明,凸轮材料烧结后密度可达7.5 g/cm3以上,硬度HRC达到53.7;材料的磨损状况与转速密切相关,在1 000--2 000 r/min转速范围内,磨损机制主要为磨粒磨损,随着转速提高,微凸体啮合程度不断降低,摩擦因数降低。磨损量则呈现先增加后减少的趋势。当转速达到3 000r/min时,以粘着磨损为主,材料磨损严重。在同样的实验条件下,该粉末冶金凸轮材料的磨损量仅为传统球墨铸铁凸轮材料的1/3,显示了优异的耐磨性。

The cams for PM sintered assembled hollow camshaft were prepared by using iron-based Fe-Cr-Mo-P-Si- Mn-Cu-C powder metallurgy sinter hardening material ,and the friction and wear properties of the cam materials under different rotate speed were studied by using MR-H5 abrasion tester and white light interferometry. The results show that the density of sintered cam material exceed 7.5 g/cm3 , and its hardness reach 53.7 HRC. The wear condition is closely related to the rotational speed. In the speed range from 1 000 to 2 000 r/min, the wear form is mainly abrasive wear. With the increasing speed, the meshing degree of micro-bulge decrease, the friction coefficient decrease, and the wearing capacity first increase and then decrease. When the speed reach to 3 000 r/min, the adhesive wear occur and cause serious abrasion. Under the same test condition, the wearing capacity of the PM cam material is only 1/3 of the conventional cast iron cam material with the same hardness, showing excellent wear resistance of the PM cam material.