摘要
利用RC-1130型蠕变持久试验机测试了时效态Mg-12Gd-3Y-1Sm-0.5Zr合金在(200、250、300℃)/(50、70、90 MPa)的条件下的拉伸蠕变行为。结果表明:当蠕变温度一定时,合金的蠕变应变随蠕变应力增加而增大;当蠕变应力一定时,蠕变应变随蠕变温度增大而增大,合金的蠕变应变对蠕变温度更敏感。由应力指数和蠕变激活能计算可知,蠕变应力为50~90 MPa,在200℃时,合金的应力指数为1.560;在250和300℃时,应力指数分别为2.230和3.602。蠕变温度为200~250℃,50 MPa下,合金的蠕变激活能为111.9 kJ/mol;当应力增大至70 MPa和90 MPa时,蠕变激活能分别为137.4 kJ/mol和142.6 kJ/mol;在250~300℃/50~90 MPa条件下,合金的蠕变激活能为126.2~87.0 kJ/mol。随着蠕变温度和应力的提高,合金的蠕变机制由晶界滑移为主转变为位错滑移为主。
The tensile creep behavior of aged Mg-12Gd-3Y-1Sm-0.5Zr alloy was studied by using a RC-1130 creep endurance testing machine under the conditions of creep temperature of 200,250 and 300℃and creep strain of 50,70 and 90 MPa.The results show that when the creep temperature is constant,the creep strain of the alloy increases with the increase of creep stress.When the creep stress is constant,the creep strain increases with the increase of creep temperature,and the creep strain of the alloy is more sensitive to creep temperature.According to the calculation of stress index and creep activation energy,when the creep stress is 50-90 MPa,the stress index of the alloy is 1.560,2.230 and 3.602 at 200℃,250℃and 300℃,respectively.When the creep temperature is 200-250℃and the stress is 50 MPa,the creep activation energy of the alloy is 111.9 kJ/mol.When the stress increases to 70 MPa and 90 MPa,the creep activation energy is 137.4 kJ/mol and 142.6 kJ/mol,respectively;under the conditions of 250-300℃and 50-90 MPa,the creep activation energy of the alloy is 126.2-87.0 kJ/mol.With the increase of creep temperature and stress,the main creep mechanism of the alloy changes from grain boundary slip to dislocation slip.
作者
付三玲
李全安
张清
FU San-ling;LI Quan-an;ZHANG Qing(College of Physics and Engineering,Henan University of Science and Technology,Luoyang 471023,China;School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology,Henan Province,Luoyang 471023,China)
出处
《材料热处理学报》
CAS
CSCD
北大核心
2022年第8期37-44,共8页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51571084,51171059)
河南科技大学博士科研启动基金项目。
