ZL114A电弧熔丝增材制造、热处理工艺及组织与性能研究

Wire arc additive manufacturing,heat treatment,microstructures and mechanical property of ZL114A alloy

采用电弧熔丝增材制造(Wire Arc Additive Manufacture,WAAM)成形技术对ZL114A合金成形工艺进行了研究,分析了WAAM成形沉积态和热处理试样微观组织及力学性能。结果发现:沉积态的微观组织由树枝状晶的α-Al基体和颗粒状共晶Si相组成,并且相邻两道焊缝的重叠区域形成粗晶区;相较于传统金属型铸造,沉积态晶粒更加细小、共晶Si相细小均匀分布;经T6热处理后,树枝晶消失,共晶Si相发生球化,呈细小弥散状态分布,显著提升了试样的力学性能:电弧熔丝增材ZL114A合金的抗拉强度、屈服强度和延伸率分别达到370.0 MPa、310.4 MPa、8.6%,并且拉伸断口表现为韧性断裂。

The process of ZL114A alloy fabricated by wire arc additive manufacture(WAAM)was studied.The microstructure and mechanical properties of as-deposited specimens fabricated by WAAM and heattreated specimens were analyzed.The results show that the microstructure of as-deposited is composed of dendritic α-Al matrix and granular eutectic Si-phase,and the coarse crystal regions occurred in the twoneighboured welding beads in the WAAMed component.Compared with the traditional metal casting method,the microstructure of as-deposited specimens shows smaller grains and the distribution of the fine eutectic Si-phase becomes uniform.After T6 heat treatment,the dendrite in the WAAMed specimens disappears and the eutectic Si-phases are spheroidized and they show a finely-dispersed distribution.These microstructure characteristic contributes to the significant improvement of the mechanical properties.The tensile strength,yield strength and elongation of the WAAMed component are 370.0MPa/310.4MPa and 8.6%,respectively,and the surface of the tensile specimens fracture is characterized by ductile fracture.