关键词: 材料表面与界面, 粉末冶金, 凸轮材料, 表面强化, 摩擦学特性

Abstract: Microstructure, microhardness and tribological properties of ferrous P/M cam materials for automobile applications were investigated under three conditions (assintered, highfrequency induction quenched and wideband laser surface quenched). The experiment results indicate that a hardened layer is obtained on the surface of the materials after two kinds of surface hardening. Microstructure of the hardened layer is fine spiculate martensite which can help to improve the wear and friction properties of the materials. The tribological properties of laser surface quenched cam materials are slightly better than highfrequency induction quenched cam materials. With the increasing of the applied load the wear mechanism of laser quenched cam materials changes from mild oxidation wear and abrasive to severe oxidation wear, abrasive wear and delamination wear.

Key words: surface and interface of materials, P/M, cam materials, surface quenched, tribological properties