(西南交通大学机械工程学院，成都 610031)
摘 要: 采用改进后的PLINT高温可控气氛的微动磨损试验机，研究Inconel 690合金在300 ℃氮气及法向交变载荷条件下的微动磨损机制和动力学特性。结果表明: 微动运行行为与激振频率密切相关，微动的Ft-D曲线呈现摩擦力周期波动的平行四边形型特征，微动运行于滑移区。在300 ℃氮气环境中，摩擦力的动态变化可以分为5个阶段，即跑合阶段、上升阶段、峰值阶段、下降阶段和稳定阶段。Inconel 690合金的微动损伤行为强烈地依赖于载荷、位移幅值、环境温度、气氛及激振频率等试验条件。从表面损伤形貌看，损伤微结构与试验参数密切相关；由于交变法向力和切向力共同作用，微动产生叠加效应，使剥层现象更加突出。在300 ℃氮气环境下，Inconel 690合金的损伤机理主要表现为磨粒磨损和剥层。
关键字: Inconel 690合金；交变载荷；微动；高温；叠加效应；剥层
（School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, China）
Abstract:The frettingwear mechanisms and kinetic behaviours of Inconel690 alloy were investigated on the improved PLINT fretting rig under alternating loads conditions in high-temperature controlled-atmosphere environments. The results show that the fretting running behaviors are closely related to the normal excitation frequency. In parallelogram shaped Ft-D curves, the friction fluctuates periodically, and accordingly the fretting runs in the slip regime (SR). Five stages of friction force curves can be observedat 300 ℃in nitrogen environment, including initial stage, ascending stage, peak value stage descending stage and steady stage. The fretting wear behaviors for Inconel 690 alloy strongly depend on the normal load, displacement amplitude, temperature, atmosphere, excitation frequency and other test conditions. The super position effect of fretting wear behavior due to the combined effect of alternating normal force and tangential force is produced, so that delamination phenomenon becomes much more prominent. The abrasive wear and delamination are the major mechanisms of Inconel 690 at 300 ℃ in nitrogen environment.
Key words: alternating load; fretting wear; high temperature; superposition effect; delamination
