Abstract
In order to satisfy the weight and cost reduction of camshaft for trucks and buses, and to improve its wear resistance, it is effective to adopt the composite camshaft which is connected by diffusion-join process between steel shaft and cam lobe. Damage mode between slipper type tappet which is widely adopted for OHV type diesel engines and cam lobe is scuffing and pitting. Thus, it has become necessary to adopt the sintered materials, for cam lobe, which has great resistance to scuffing and pitting. We have developed a Fe based sintered materials for cam lobe to be used together with widely adopted low cost hardened chilled-cast iron tappet. The material for cam lobe has great resistance to scuffing with precipitating of a large quantity of fine Cr-carbide, and has great resistance to pitting with strengthening the matrix by containing a proper amount of Mo and Ni.
