孔挤压与超载复合强化对LY12CZ铝合金疲劳裂纹起始寿命的影响

Effect of the Comptex Strengthening of Hole Cold Expansion and Overloading on FCIL of LY12CZ Aluminum Alloy

研究了孔挤压与超载复合强化对LY12CZ铝合金疲劳裂纹起始寿命的影响。实验结果与分析表明,孔挤压与超载复合强化对LY12CZ铝合金的疲劳裂纹起始寿命及裂纹萌生、扩展特性的影响和孔挤压单一强化效果相同。此外还给出了复合强化后LY12CZ铝合金疲劳裂纹起始寿命的定量表达式,以及变幅载荷下LY12CZ铝合金孔挤压件疲劳裂纹起始寿命的估算新方法。

The effect of the compeex strengtheing of hole cold expauson (HCE) and overloading on the fatigue crack initiation file (FCIL) of LY12CZ aluminum alloy sheets had been investigated. Experimental result show that within the commonly applied range of HCE, overloading has Sew effect on the fatigue crack initiation and propagation. And a quantitative expression of FCIL for the complex strengthening is given. Besides, a new method has been put forward to predict the FCIL of HCE for LY12CZ sheets under variable loading amplitude.