摘要
研究了不同温度条件下的7D04-T74511铝合金力学性能,并采用TEM和SEM等手段分析了不同温度下拉伸试样断口的微观组织。研究结果表明:随温度升高,合金的强度显著下降,且随温度的升高其影响逐渐加剧;结合TEM微观组织观察,125℃以下时发生轻微的二次析出,部分弥补热激活造成的强度下降,强度下降趋势较缓;而当温度升高到150℃以上时,该合金中的沉淀相发生粗化,且随温度升高粗化速度加快,强度下降逐渐加速;通过SEM断口分析,室温拉伸时,合金强度较高、塑性较低。因此,剪切区域主要发生穿晶剪切断裂。随着温度的升高,断口中高温滑移特征以及基体/沉淀相界面的滑脱越来越显著。
Mechanical properties of 7D04-T74511 aluminum alloy at different temperature was investigated,and microstructure of remaining specimen was examined by TEM and SEM. The results indicated that the strength of alloy significantly fell with the increase of temperature,and the influence increased gradually. Combined with TEM test,secondary precipitation occurred slightly under 125℃,partially the decrease in strength caused by thermal activation,the strength decreased slowly,and when the temperature rose above 150℃,the precipitates in the alloy were coarsened,and speeded with the rough of temperature,the impact of strength with the temperature gradually increased. Fracture analyzed by SEM,when stretching at the room temperature,the alloy was high strength and low ductility,therefore transgranular fracture at the clipping region mainly occurred,with increasing temperature,the slipping characteristics and substrate /precipitation phase interface more and more significantly slipped.
出处
《轻金属》
CSCD
北大核心
2014年第8期50-53,共4页
Light Metals
关键词
7D04铝合金
高温
力学性能
微观组织
7D04 aluminum alloy
high temperature
mechanical properties
microstructure
