摘要
采用显微组织观察、性能测试相结合的方法,研究了220℃和250℃过时效热处理制度对2A70铝合金自由锻件(固溶+时效)的显微组织、硬度和室温拉伸性能的影响规律。结果表明:固溶+时效状态的2A70自由锻件经220℃的过时效,随时间的延长其组织、硬度和室温拉伸性能有一段转好上升,然后再转差下降至崩溃;而250℃的过时效将直接导致其组织、硬度和室温拉伸性能崩溃。2A70自由锻件固溶+时效状态的典型显微组织为α-Al+S(Al2CuMg)+Mg2Si相,随着过时效温度、时间的增加,原始晶界逐步淡化、局部出现再结晶、原始晶界消失、基体析出颗粒相,而S(Al2CuMg)相无明显变化。随着颗粒析出相的增加,试样的硬度和室温拉伸性能整体呈下降趋势。
The effects of 220℃ and 250℃overaging treatments on the microstructure,hardness and room temperature properties of 2A70 Al-alloy hand forging(solution+aging)were studied by using the methods of microstructure observation and the mechanical property test.The results show that when the 2A70 free forging of solution and aging state is overaging at 220℃,the microstructure,hardness and room temperature tensile properties increase with time increasing,and then turn to be bad until they collapse.But when the overaging temperature increases to 250℃,the microstructure,hardness and tensile properties collapse directly.After solution treatment and aging process,the typic microstructure of the 2A70 free forging isα-Al+S(Al2CuMg)+Mg2Si.With the overaing temperature and time increasing,grain boundary is weaken,local recrystallization,disappearance of grain boundary,precipitation of particles from matrix occur,but the S(Al2CuMg)phase has no obvious change.With the particle precipitation phase increasing,the hardness and mechanical properties decline generally.
作者
龚侯
林楚新
曹奔
GONG Hou;LIN Chuxin;CAO Ben(AECC Hunan Powerplant Research Institute, Zhuzhou 430070, China)
出处
《热加工工艺》
北大核心
2019年第12期161-164,共4页
Hot Working Technology
关键词
2A70
过时效
组织
硬度
力学性能
2A70
overaging
microstructure
hardness
mechanical property
作者简介
龚侯(1988-》女,湖南益阳人,工程师,本科,主要研究方向为材料测试与分析;电R:15873378551^-maiM12524095@qq.com.
