摘要
研究了７０７５铝合金、２０９Ｏ和２０９０＋Ｃｅ铝锂合金的疲劳门槛值、门槛值附近断口的分形维数及其断口形貌间的关系。结果表明，断口分形维数（ＤＦ）和裂纹闭合应力强度因子门槛值（ΔＫＣｌ．ｔｈ）间呈如下关系：ΔＫＣｌ．ｔｈ＝２４．２１ＤＦ－２６．１１，这归因于断口表面粗糙度的变化及其诱发的高的裂纹闭合效应。微量Ｃｅ的加入提高了２０９０铝锂合金的本征疲劳裂纹抗力，但对分形维数并无贡献。
Abstract The relationship among fatigue threshold range,fractal dimension of fatigue surface near threshold area and fracture surface morphology for aluminium alloy 7075, Al-Li alloys 2090 and 2090+Ce was investigated. The results in this research show that fractal dimension (DF) and crack closure stress intensity threshold range (ΔKCl.th ) give a linear function: ΔKCl.th = 24. 21DF - 26. 11, this due to the changing of fracture surface roughness and the high level of crack closure effect which induced by the fracture surface roughness. The intrinsic growth resistance for alloy 2090 is enhanced by the addition of minor Ce, but it contributes nothing to fractal dimension.
出处
《机械工程材料》
CAS
CSCD
1994年第6期34-36,共3页
Materials For Mechanical Engineering
