摘要
研究了A357-T6铸造铝合金在室温大气中正弦交变载荷下,应力比分别为r=-1,0.05和0.4时的疲劳特性。试验结果表明,A357-T6铸造铝合金的疲劳强度随应力比的增加而显著增加,疲劳极限分别是,应力比r=0.4时约为135MPa;应力比r=0.05时95MPa;而应力比为r=-1时70MPa。疲劳裂纹发生于试件表面或次表面铸造缺陷。裂纹沿着树状晶边界扩展。
The fatigue properties of A357 - T6 casting aluminum alloy were studied at three stress ratios, r, of - 1,0.05 and 0.4 in laboratory air at ambient temperature under load control with alternatc sinusoidal wave form in this paper. The experimental results show that the fatigue strengths of A357 - T6 casting aluminum alloy increase with increasing stress ratios, the fatigue limits are 135MPa for r =0.4, 95MPa for r =0.05 and 70MPa for r = - 1 respectively. Fatigue cracks initiated from defects at specimen surface or casting defects in sub -surface. Fatigue crack propagates along dendrite boundary.
出处
《沈阳航空工业学院学报》
2009年第2期9-11,共3页
Journal of Shenyang Institute of Aeronautical Engineering
基金
辽宁省教育科学基金(项目编号:20060659)
关键词
A357-T6铸造铝合金
疲劳
断口
A357 - T6 casting aluminum alloy
fatigue
fracture surface
