摘要
Wire-arc additive manufacture(WAAM)has great potential for manufacturing of Al-Cu components.However,inferior mechanical properties of WAAM deposited material restrict its industrial application.Inter-layer cold rolling and thermo-mechanical heat treatment(T8)with pre-stretching deformation between solution and aging treatment were adopted in this study.Their effects on hardness,mechanical properties and microstructure were analyzed and compared to the conventional heat treatment(T6).The results show that cold rolling increases the hardness and strengths,which further increase with T8 treatment.The ultimate tensile strength(UTS)of 513 MPa and yield stress(YS)of 413 MPa can be obtained in the inter-layer cold-rolled sample with T8 treatment,which is much higher than that in the as-deposited samples.The cold-rolled samples show higher elongation than that of as-deposited ones due to significant elimination of porosity in cold rolling;while both the T6 and T8 treatments decrease the elongation.The cold rolling and pre-stretching deformation both contribute to the formation of dense and dispersive precipitatedθ′phases,which inhibits the dislocation movement and enhances the strengths;as a result,T8 treatment shows better strengthening effect than the T6 treatment.The strengthening mechanism was analyzed and it was mainly related to work hardening and precipitation strengthening.
电弧增材制造技术在铝-铜合金构件制造中极具潜力,然而增材制造构件较低的力学性能限制了其在工业中的应用。本文将层间冷轧和形变热处理(T8)同时集成到电弧增材铝-铜合金中,通过在固溶和时效工艺过程中添加预拉伸变形实现形变热处理,研究了形变热处理和层间冷轧对构件硬度、微观组织和力学性能的影响规律,并与传统T6热处理进行了对比分析。结果表明层间冷轧可以提升材料硬度和强度,形变热处理可进一步提升其数值。结合层间冷轧和T8热处理,可获得513 MPa抗拉强度和413 MPa屈服强度的试件,这远高于电弧增材态试件。与电弧增材态试样相比,层间冷轧能显著消减气孔,获得更高的伸长率。层间冷轧和T8热处理均有利于形成细小、弥散分布的θ′析出相,有利于阻碍位错运动,提升强度,T8热处理能获得比传统T6热处理更好的强化效果。层间冷轧和T8热处理综合作用下的强化机制主要取决于材料的加工硬化和析出强化机制。
作者
ZHANG Tao
QIN Zhen-yang
GONG Hai
WU Yun-xin
CHEN Xin
张涛;秦振洋;龚海;吴运新;陈鑫(Light Alloy Research Institute,Central South University,Changsha 410083,China;State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University,Changsha 410083,China;Welding and Additive Manufacturing Centre,Cranfield University,Bedford,MK430AL,UK)
基金
Project(ZZYJKT2024-08)supported by the State Key Laboratory of Precision Manufacturing for Extreme Service Performance,China
Project(2022JB11GX004)supported by Selection of the best Candidates to Undertake Key Research Projects by Dalian City,China
Project(201806835007)supported by China Scholarship Council。
