Optimization of shape and performance for wire and arc additive manufacturing with in-situ rolling of Ti–6Al–4V ELI alloy
Youheng Fu, Xi Chen, Mingbo Zhang, Xiangman Zhou, Li R, Xingwang Bai, Guilan Wang
Abstract
The purpose of this paper is to establish the quantitative relationship between the wire and arc additive manufacturing (WAAM) process parameters and four objectives including the size, heat input, grain and performance. So as to lay a good initial shape and performance foundation for the subsequent in-situ rolling. The experimental matrix was designed based on the response surface methodology (RSM) and the multi-objective optimization was performed based on the forming efficiency and deformation uniformity. All of the final polynomial models showed that the F -ratio is greater than the corresponding F 0.05 and the P -value is less than 0.0001 in the 95% confidence level significance test. The optimum initial states showed good reactions when set at w = 2.5 m/min, v = 187 mm/min, I = 178 A, T = 93 °C. Compared with the original high-efficiency deposition processes with higher overlapping rate and constant force, the optimized deposition processes with optimal offset and constant deformation can result in more uniform and refined grain structures, leading to a 5.9% increase in average tensile strength and a 37.8% enhanced in average elongation. These findings lay a solid foundation for optimizing the high-precision and high-performance hybrid additive manufacturing (HAM) process planning of titanium alloy forgings.