TC4钛合金的微动疲劳行为研究

Study on Fretting Fatigue Behavior of TC4 Titanium Alloy

摘要:

研究了TC4钛合金在柱面-平面接触条件下的微动疲劳行为.通过观察微动区的磨损特征和截面形貌,分析了微动疲劳损伤机制,探讨了磨屑的形成与演变过程及其对微动疲劳行为的影响,考察了摩擦系数随时间的变化.结果表明,TC4钛合金微动区的损伤机制以粘着磨损、磨粒磨损和接触疲劳为主,并伴有氧化磨损.磨屑是基体材料脱落、破碎、氧化形成的,磨屑中的硬质氧化物颗粒促进了合金表面的磨粒磨损,加速了疲劳失效.

Abstract:

The fretting fatigue behavior of TC4 titanium alloy was investigated using a cylinder-plane configuration. Through the observation of worn surface and cross-section, the formation and evolving process of the fretting debris and the effects during fretting fatigue were discussed. The variation of friction coefficient with time was analyzed. Based on the experimental results of TC4 titanium alloy, it is found that the damage mechanism of fretting fatigue was adhering wear, abrasive wear and contact fatigue, accompanying with oxidation wear. The fretting debris were formed from the break-off and crushing of the parent alloy, then oxidization to be the fragments during the fretting fatigue test. It promoted the abrasive wear and accelerated the fatigue failure due to the hard oxide particles in fretting debris. The friction coefficient rapidly increased with time in the initial stage, then kept stable in the stable stage.