ER2319 welding wires were used to fabricate a wall structure using CMT-PAdv-based wire and arc additive manufacturing (WAAM). Heat treatment was used after the WAAM process. The microstructure and mechanical property anisotropy before and after the heat treatment were studied. There were three areas with different grain morphology along building direction in the as-deposited wall structure. Microstructure difference was clear between interlayer regions and intra-layer regions both in as-deposited and heat-treated state. Netlike second phases became discontinuous after heat treatment, but pores and Fe-rich phases basically unchanged. Mechanical property presented isotropy before heat treatment because α-Al with lower Cu content had low resistance on crack initiation or growth and crack mainly grew via netlike second phases which had no directionality. Mechanical property presented anisotropy after heat treatment because α-Al was strengthened and brittle Fe-rich phases which concentrated in interlayer regions played a leading role in crack initiation. Moreover, the tensile loading force along the building direction was perpendicular to interlayer regions. Thus, mechanical properties in building direction were lower than that in deposition direction.

ER2319焊丝用于制造基于CMT-PAdv的焊丝和电弧增材制造（WAAM）的墙结构。在WAAM过程之后进行热处理。研究了热处理前后的微观组织和力学性能各向异性。沉积后的墙体结构中，沿构造方向存在三个具有不同晶粒形态的区域。在沉积状态和热处理状态下，层间区域和层内区域之间的微观结构差异明显。热处理后的网状第二相变得不连续，但孔和富铁相基本不变。热处理前的力学性能表现为各向同性，这是因为具有较低Cu含量的α-Al对裂纹萌生或扩展的抵抗力较低，并且裂纹主要通过无方向性的网状第二相生长。热处理后的力学性能呈现各向异性，这是因为α-Al增强并且富集在中间层区域中的脆性富铁相在裂纹萌生中起主导作用。此外，沿构建方向的拉伸载荷力垂直于夹层区域。因此，建筑方向上的机械性能低于沉积方向上的机械性能。沿建筑方向的拉力垂直于夹层区域。因此，在建造方向上的机械性能低于在沉积方向上的机械性能。沿建筑方向的拉力垂直于夹层区域。因此，在建造方向上的机械性能低于在沉积方向上的机械性能。