汽油机铝合金缸孔等离子喷涂摩擦学性能研究

在汽油机铝合金缸体内孔表面,采用大气等离子喷涂(APS)方法制备了1层厚度为150μm左右的铁基涂层来替代传统的铸铁缸套.对缸孔的涂层进行表征,并对缸孔-活塞环摩擦副进行了摩擦试验.试验表明,在铝合金缸孔喷涂等离子铁基涂层,可提高缸孔的硬度,并提高发动机的耐久性和抗拉缸性,使发动机实现轻量化目标.涂层表面精度接近镜面级别,且涂层内含有孔隙,可降低缸孔-活塞组的摩擦系数及摩擦损失,提高发动机燃油经济性.     

Dry sliding wear behavior of silver containing Ni-based composite-steel tribo-pair

Ni-based self lubricating composites containing four different amounts of silver were prepared by powder metallurgy (PM) route. The room temperature friction and wear behavior was investigated by carrying out dry sliding experiments against bearing steel using a ring-on-disk configuration. Tests were conducted at a constant load of 100N and different sliding speeds of 0.5, 1.0 and 1.5 m/s to analyze the effect of both the speed and the silver content on the wear behavior of the tribo-pair. The friction coefficient and the wear rate of the composites were found to decrease with increasing both the sliding speed and the silver content. The wear rate of the counterface was observed to be a little higher when it was siding against the composite having silver in comparison to that without any silver. However, the overall wear rate of the tribo-pair was found to decrease with increasing sliding speed and silver content.