Evolution of precipitates and mechanical properties of T6-treated and thermally exposed WAAM-ZL205A alloy  

经T6和热暴露处理WAAM-ZL205A合金的析出相和力学性能演变

作　　者：Hai-jiang LIU Yan FENG Chao-qun PENG Zhi-yong CAI Meng WANG Zi-ming LI Zhi-jie KANG Xiao-di ZHANG 刘海江;冯艳;彭超群;蔡志勇;王檬;李梓铭;康智杰;张晓笛(中南大学材料科学与工程学院,长沙410083;中南大学高强结构材料科学与技术国家重点实验室,长沙410083)

机构地区：[1]School of Materials Science and Engineering,Central South University,Changsha 410083,China [2]National Key Laboratory of Science and Technology on High-strength Structural Materials,Central South University,Changsha 410083,China

出　　处：《Transactions of Nonferrous Metals Society of China》2025年第3期684-700,共17页中国有色金属学报(英文版)

基　　金：the financial support from the National Natural Science Foundation of China (No. 52274369);the Science and Technology Program of Hunan Province, China (No. 2020GK2044)。

摘　　要：The microstructure and mechanical properties of the WAAM-ZL205A alloy were investigated at various thermal exposure temperatures and compared with those of the deposited and T6-treated alloys.Due to the precipitation strengthening of fine and scattered θ″and θ′phases,the yield strength(YS)of the T6-treated((535℃,10 h)+(175℃,10 h))alloy increases to 366.9 MPa compared with that of the deposited alloy.However,the elongation(El)is reduced to 12.9%.When the thermal exposure temperature increases from 200 to 300℃,there is a notable decrease in YS and the time required to stabilize is shortened.After thermal exposure at 300℃ for 24 h,part of the θ′precipitate located at the grain boundary transforms into the θ phase,while the θ′precipitate within the grains experiences coarsening,resulting in a decrease in YS to 188.9 MPa.Upon surpassing an exposure duration of 120 h,the mechanical characteristics exhibit stability.研究不同热暴露温度下WAAM-ZL205A合金的显微组织和力学性能,并将其与沉积态和T6态合金进行对比。与沉积态合金相比,T6处理(535℃, 10 h)+(175℃, 10h)合金的屈服强度增加至366.9MPa,这归因于细小、弥散的θ′′和θ′相的析出强化,但伸长率降低至12.9%。随着热暴露温度从200℃升高至300℃,合金的屈服强度显著下降,而达到性能稳定所需的时间缩短。300℃热暴露24 h后,晶界处部分θ′相转变为θ相,晶内的θ′相明显粗化,导致屈服强度降低至188.9 MPa。当热暴露时间超过120 h后,合金的力学性能趋于稳定。

关 键 词：ZL205A Al alloy PRECIPITATE mechanical properties additive manufacturing heat treatment thermal exposure stability 

分 类 号：TG1[金属学及工艺—金属学]