70摩托车活塞表面“白斑”的形成原因分析

Analysis of "White Smudge" on Surface of 70 Motorcycle Piston

对７０摩托车活塞表面“白斑”现象从宏观与微观的角度进行了详细的分析，并进行了材质与切削条件两个方面的试验，认为切削过程中形成的积屑瘤和材质的强化不均匀致使“白斑”形成，还从切削过程和材质两个方面对“白斑”的形成机理进行了探讨，确定了有效的消除“白斑”的措施。

White Smudges' on the machined surface of 70 motorcycle piston made of a eutectic Al-St alloy have been analyzed, and the influence of heat treatment and machine conditions on the production of 'white smudge' have been investigated. The results shows that the built-up-edge and the microstructure heterogeneity results in 'white smudge '. The mechanism of the production of 'white smudge' is discussed based on machine processes and the microstructure. A effective method to avoid the smudge is proposed