2219铝合金电弧增材制造组织及力学性能的非均匀性

Inhomogeneity of Microstructures and Mechanical Properties of 2219 Aluminum Alloy by WAAM

采用基于CMT工艺的电弧增材制造(WAAM)技术成形了2219铝合金单壁墙试样,并研究了沉积态、固溶态、固溶+时效态的显微组织与力学性能。结果表明,显微气孔、θ(Al2Cu)及富Fe脆性相在层间密集分布形成薄弱带,是导致水平方向和垂直方向力学性能各向异性的原因。垂直方向拉伸时,微裂纹易于在层间形成,塑性较差、抗拉强度较低。为提高WAAM成形的2219铝合金垂直方向力学性能,需尽可能降低丝材中的Fe、Si杂质含量。

Single wall specimens of 2219 aluminum alloy were built by wire and arc additive manufacturing(WAAM)technology using CMT welding process.The microstructure characteristics and mechanical properties in as-deposited state,solid solution state and artificial aging state were investigated.Results show that the weak strips with micro porosities,θ(Al2Cu)phases and iron rich phases in the interlayer region result in the anisotropic mechanical properties of the WAAM specimens.When the specimens are tensioned in the vertical direction,cracks form easily in the interlayer region,and the tensile strength and plasticity deteriorate.In order to increase the mechanical properties of WAAM 2219 aluminum alloy in the vertical direction,the content of Fe and Si in the wire should be as low as possible.