摘要
研究了定向凝固高温合金ＤＺ１７Ｇ在不同加载取向及加载频率条件下的室温疲劳裂纹扩展行为。结果表明，９０°加载取向试样的裂纹扩展速率最快，０°试样次之，４５°试样由于裂纹宏观扩展路径发生偏折而导致其扩展速率最低。加载频率对裂纹扩展速率的影响与应力强度因子范围ΔＫ的大小有关。沉淀相γ′的尺寸对微观疲劳位错形貌有明显影响。微裂纹沿γ通道扩展。
Fatigue crack growth behavior of DZ17G at room temperature is studied at different testing conditions of loading direction and loading frequency.The results indicate that the fatigue crack growth rate(FCGR) is the largest on the specimen with loading angle 90°,smaller on that with loading angle 0°,and the smallest on that with loading angle 45° due to crack deflection effect.The influence of loading frequency upon FCGR is related to the range of stress intensity factor ΔK.The dimension of precipitate γ′ has influence upon the dislocation arrangement.Microcracks propagate along the γ channel.
出处
《航空材料学报》
EI
CAS
CSCD
1999年第1期39-44,共6页
Journal of Aeronautical Materials
关键词
定向凝固
高温合金
加载
疲劳裂纹
扩展速率
DS superalloy
loading direction
loading frequency
fatigue crack growth rate
