电弧增材制造(WAAM)ZL114A铝合金组织与性能的研究

Investigation on microstructure and properties of aluminum alloy (ZL114A) by wire arc additive manufacturing (WAAM)

摘要:

采用金相显微镜、扫描电镜、电子万能试验机等分析测试手段，研究了电弧增材制造工艺方法对ZL114A铝合金组织与性能的影响。与传统铸造成形方法相比，铸态组织具有更小的枝晶间距、Si相细小分布均匀；化学成分可有效控制；T6热处理后，Si相球化充分，第二相弥散分布在α-Al基体上，力学性能显著提升，抗拉强度、屈服强度及延伸率分为360MPa、315MPa、7.5%，延伸率是砂型铸造试样的2.1倍，拉伸断口呈现韧性断裂特征。WAAM成形试样缺陷主要为小于30μm的气孔，经过热处理后气孔数量减少，尺寸有变大趋势。

关键词:WAAM、电弧增材制造、铝合金、组织与性能、缺陷

Abstract:

The effect of wire arc additive manufacturing process on the structure and properties of aluminum alloy (ZL114A) was studied by means of metallographic microscope, scanning electron microscope and electronic universal test. Compared with the traditional casting method, the structure of as-deposited WAAM ZL114A has smaller dendrite spacing, the distribution of fine Si-phase is uniform, and the chemical composition is controlled effectively. Through T6 heat treatment process, Si-phase is fully spheroidized and the second phase is dispersed on the matrix of alpha-Al. Meanwhile, the mechanical properties are significantly improved. The tensile strength, yield strength and elongation are 360MPa, 315 MPa and 7.5%, respectively. Especially, the elongation is 2.1 times than that of sand casting sample, and the tensile fracture is characterized by ductile fracture. The defects of ZL114A(WAAM) are mainly pores less than 30 μm. After heat treatment, the number of pores decreases and the size increases.

Key words:WAAM, Wire;arc additive;manufacturing, Aluminum;alloy, Microstructure;and properties, Defect