柴油机钛合金活塞裙部失效分析研究

针对某适度隔热柴油机在标定工况下，TC4钛合金活塞裙部两侧发生磨损失效的问题，采用金相组织分析、电镜扫描等方法对活塞裙部磨损区域进行微观分析，再结合有限元分析软件ABAQUS对活塞裙部进行变形量的宏观分析，共同探究柴油机活塞裙部的磨损失效机理. 分析结果表明，活塞裙部变形量最大区域与磨损区域相吻合，失效的主要原因是活塞裙部刚度不足，在高温高压作用下产生变形与缸套发生黏着磨损. 通过改进活塞主要结构参数，使得裙部变形小于二次修正值，从而避免活塞裙部四点磨损失效问题. 

Analysis on Titanium Alloy Piston Skirt Failure of Diesel Engine

To solve the problem of wear failure occurred on both sides of the TC4 titanium alloy piston skirt in a high power density diesel engine under standard operating conditions, a microscopic analysis on the wear area of the piston skirt was carried out by combining metallographic analysis, electron microscope scanning and other physical and chemical detection methods firstly. And then, a finite element analysis software ABAQUS was used to conduct a macroscopic research on the stress and deformation of the piston skirt. The microscopic and macroscopic analysis methods were combined to explore the wear failure mechanism of the piston skirt. The results show that the area of maximum piston skirt deformation coincides with the wear area. The analysis results indicate that main reason of the failure is the insufficient stiffness of the piston skirt, deformation occurred under the high temperature and high pressure, and adhesive wear with the cylinder liner. Finally, some improved piston tests were carried out. Improving the main structural parameters of the piston, it can make the skirt deformation less than the predetermined secondary correction value, avoiding the problem of four-point wear on the piston skirt.