Effects of arc mode on morphology, microstructure and mechanical properties of titanium alloy wire arc additive manufacturing

Abstract

Wire arc additive manufacturing (WAAM) offers a practical approach for the manufacture of large, complex, and specialized components for structural applications, with high deposition efficiency and cost-effectiveness. This paper aims to reveal the relationship between the arc mode, microstructure, and mechanical property. The effect of arc mode on process stability, structural robustness, microstructure, and mechanical properties of the additively manufactured Ti–6Al–4V component was explored. Analyses were performed utilizing XRD, OM, SEM-EDS, EBSD, and standard tensile testing. Results demonstrate that both CMT-arc and GMA-arc additive manufacturing processes derive stable, efficient, and structurally robust builds. While maintaining consistent deposition rates and scanning speeds, CMT-arc exhibits reduced heat input and increased cooling rates relative to GMA-arc, leading to a optimized solidification structure. The UTS of both CMT-arc and GMA-arc AM specimens measured horizontally surpass 970 MPa. Attributable to its lower heat input and finer solidification structure, CMT-arc produces components with enhanced tensile strength and microhardness compared to GMA-arc. This work contributes to a deeper understanding of the effects of arc mode on deposition properties in the additive manufacturing process, informing future process control, and optimization.

Keywords

• Arc mode
• WAAM
• Microstructure
• Mechanical property