摘要
目的研究热处理时效时间对激光增材制造Al-Mg-Sc-Zr合金微观组织与拉伸性能的影响,揭示微观组织与力学性能的内在关联机制。方法采用控制单一变量的试验方法进行时效热处理,设定保温温度为325℃,冷却方式为空冷,在不同保温时间(2、4、6、8 h)下进行组织与性能共通性及差异性分析。结果经325℃时效热处理4 h后,在激光增材制造Al-Mg-Sc-Zr高强铝合金中形成了Al_(3)Sc、Al_(3)(Sc,Zr)析出相,抗拉强度达到最大值486 MPa,相较于未热处理,提升了21.8%,随着保温时间的进一步延长,析出相的高温停留时间变长,组织形核长大,Al_(3)Sc、Al_(3)(Sc,Zr)强化相尺寸明显增大,最大尺寸可达0.6μm。结论随着时效时间的延长,沉积道次间重熔边界逐渐不明显,热处理有助于Al_(3)Sc、Al_(3)(Sc,Zr)析出相的形成,而保温时间过长则容易导致析出相尺寸粗大,合理的热处理保温时间可以改善激光增材制造Al-Mg-Sc-Zr合金微观组织与力学性能。
The work aims to study the effect of heat treatment aging time on the microstructure and tensile properties of la-ser additive manufactured Al-Mg-Sc-Zr alloy and reveal the internal correlation mechanism between microstructure and me-chanical properties.The aging heat treatment was conducted by a single variable control test method.The holding temperature was set at 325 and the cooling method was air cooling.The commonality and difference of microstructure and properties after℃different holding time(2,4,6,8 h)were analyzed.After aging heat treatment at 325 for 4 h,precipitates of Al℃3Sc and Al_(3)(Sc,Zr)were formed in Al-Mg-Sc-Zr high-strength aluminum alloy made by laser additive manufacturing,and the tensile strength reached the maximum value of 486 MPa,which increased by 21.8%compared with that without heat treatment.With the further extension of holding time,the precipitates had a long residence time at high temperature.The size of Al_(3)Sc and Al_(3)(Sc,Zr)strengthening phase increased significantly,with the maximum size up to 0.6μm.With the increase of aging time,the remelting boundary between deposition passes gradually becomes less obvious.Heat treatment is conducive to the for-mation of Al_(3)Sc and Al_(3)(Sc,Zr)precipitates,while too long holding time will easily lead to coarse precipitates.Reasonable heat treatment holding time can improve the microstructure and mechanical properties of laser additive manufactured Al-Mg-Sc-Zr alloy.
作者
段宇航
王磊磊
郝璐静
原帅超
赵艳秋
占小红
DUAN Yuhang;WANG Leilei;HAO Lujing;YUAN Shuaichao;ZHAO Yanqiu;ZHAN Xiaohong(College of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China)
出处
《精密成形工程》
北大核心
2024年第5期48-54,共7页
Journal of Netshape Forming Engineering
基金
国家重点研发计划(2022YFB4602300)。
