铝合金双丝VP-GTAW增材构件组织和性能

Microstructure and Properties of Double-Wires plus Arc Additive Manufactured Aluminium Alloy Deposits Using VP-GTAW Process

摘要:

以Al-6.3Cu+Al-5Mg为填丝材料进行铝合金双丝VP-GTAW增材制造试验。结果表明，采用双丝VP-GTAW制备试样可提高成形效率，且成形稳定；通过调节两种丝材的送丝速度可以获得不同主要合金元素含量的Al-Cu-Mg合金，合金组织主要由柱状晶和等轴枝晶组成，且呈非均匀分布特征，调节主要合金元素含量可实现对铝合金试样性能的控制。原始状态下铝合金试样的显微硬度为90-100HV，抗拉、屈服强度分别可达286MPa和183MPa，但塑性较差，仅为4.5%。

关键词:双丝VP-GTAW增材;Al-Cu-Mg合金;微观组织;力学性能

Abstract:

Double-wires plus arc additive manufacturing(D-WAAM) system for Al-Cu-Mg alloy using variable polarity gas tungsten arc welding(VP-GTAW) process was established. Al-6.3Cu and Al-5Mg wires were employed as filling metal, the microstructure and mechanical properties of as-deposited D-WAAM samples were analyzed. Experimental results show that the excellent deposits wall samples can be achieved and the deposition efficiency can be improved by using D-WAAM process. Al-Cu-Mg alloys with different element content of copper and magnesium were obtained by adjusting the two wire feed speed. The microstructures of Al-Cu-Mg deposits were mainly composed of columnar dendrite and equiaxed dentrite grains with the non-uniformly distribution characteristics. Mechanical properties can be enhanced due to the addition of alloying of element magnesium. The microhardness of as-deposited Al-Cu-Mg alloy was 90-100 HV. The UTS, YS and elongation of as-deposited D-WAAM alloy can be increased to 286 MPa, 183 MPa and 4.5%, respectively.

Key words:D-WAAM; VP-GTAW; Al-Cu-Mg alloy; Microstructure; Mechanical properties