高级检索

TA1钛合金自冲铆接接头疲劳性能及失效机理分析

Fatigue property and failure mechanism of self piercing riveted joints of TA1 titanium alloy

  • 摘要: 采用轴向加载的形式对TA1钛合金自冲铆接试样进行疲劳试验,分析了不同因素下试样的疲劳强度变化规律;通过扫描电镜对试样失效断口和微动磨损进行分析,研究试样的失效机理. 结果表明,在同种铆接因素下,试样疲劳强度随应力比的增大而增大,随最大载荷值的增加而下降. 通过断口分析发现,铆钉断裂失效时,疲劳裂纹主要产生在钉胫外侧;基板断裂失效时,疲劳裂纹首先萌生在铆钉胫尾部与下板接触区域. 基板与铆钉的微动磨损在某种情况下存在竞争机制,当铆钉微裂纹扩展速率大于基板时表现为铆钉失效,反之为基板失效.

     

    Abstract: The fatigue tests of self-piercing riveting TA1 titanium alloy were carried out by axial loading, and the fatigue strength of the joints under different factors was analyzed. The failure fracture and fretting wear of the joints were analyzed by scanning electron microscopy (SEM), and the failure mechanism of specimen was studied. The results show that the fatigue strength increases with the increase of stress ratio and decreases with the increase of maximum load value under the same riveting conditions. It is found that the fatigue cracks mainly occur on the outside of the rivet leg when the rivet is broken, and the fatigue cracks first occur in the contact area between the rivet tail and the lower sheet when the sheet is broken. There is a competitive mechanism for the fretting wear between the lower sheet and the the rivet. When the crack growth rate of the rivet was greater than that of the lower sheet, the rivet would be failure, and on the contrary, lower sheet would be failure.

     

/

返回文章
返回