Molding performances of ZL205A aluminum alloy fabricated by wire arc additive manufacturing based on gray correlation theory

Evaluation indicators such as aspect ratio, dilution rate, microhardness, wear resistance and electrochemical corrosion resistance are crucial to assess the quality of arc additive manufacturing of aluminum alloys. This paper investigated the impact of the process parameters of the Cold Metal Transfer (CMT) arc additive manufacturing on molding performances of single pass-single layer samples. A three-factor, three-level orthogonal table was devised incorporating welding speed, wire feed speed, and dry extension as the three principal process parameters. Combined with the gray correlation theory, the Shape-Performance Coefficient (SPC) was established to provide a comprehensive evaluation of the molding performances of the samples. The results indicated that the priority sequence of the three process parameters on molding performances was wire feed speed, welding speed, and dry extension. The ideal process parameters are: a welding speed of 9 mm/s, a wire feed speed of 4 m/min, and a dry extension of 10 mm. If the wire feed speed is too high and the welding speed is too low, the aspect ratio and dilution rate of the sample will increase, resulting in larger grain size and more porosity defects. This has the consequence of decreased wear resistance and corrosion resistance for the sample. Compared to the ZL205A cast aluminum alloy (CastZL205A), the most exceptional additive manufacturing sample exhibits a ten-fold reduction in the average grain size and a 144.88% increase in electrochemical corrosion resistance. The findings presented in this paper establish data support for thin-walled parts arc additive manufacturing with ZL205A aluminum alloy and provide a theoretical foundation for the repair of critical aluminum alloy components.