Optimization of Vacuum Brazing Process Parameters in Ti-6Al-4V Alloy

Metals

Jiun-Ren Hwang¹  Chou-Dian Huang¹  Jiunn-Yuan Huang² 

[1] Department of Mechanical Engineering, National Central University, Taoyuan 320317, Taiwan;Institute of Nuclear Energy Research, Taoyuan 325207, Taiwan;

关键词: vacuum brazing;    titanium alloy;    Taguchi method;    process optimization;    tensile strength;    microstructure;   

DOI  :  10.3390/met12060974

来源: DOAJ

【 摘 要 】

In this study, the optimal parameters of the vacuum brazing titanium alloy Ti-6Al-4V with TiCuNi filler (30 μm-thick metal foil) were investigated by the Taguchi method. The microstructures, microhardness, and fractographs of the titanium brazed joints produced by these optimal parameters were also analyzed. The results of this study demonstrate that for the best tensile strength, the optimal combination of process parameters is: 890 °C soaking temperature, 60 min soaking time, 975 °C brazing temperature, and 45 min brazing time. The tensile strength obtained by welding with the optimal parameters was found to be 1265 MPa. A small error of 0.24% between experimental and predicted values confirmed the validity of the combined optimized parameters. Finally, from the means of variance analysis (ANOVA), out of the four factors, the highest contribution to the optimal parameters was found to be the brazing time, accounting for 47.3%. The base material of vacuum brazing (VB) weldment is mainly composed of white granular α titanium, slender β titanium, and layered structures that are interlaced by α and β. The weld bead, composed of Ti-15Cu-15Ni, contains many slender needle-shaped Widmanstätten structures. This structure is associated with higher strength and lower ductility. The weld bead hardness of the vacuum brazed parts is higher than that of laser beam weldment and gas tungsten arc weldment. This study demonstrates the feasibility of the Taguchi method for obtaining the optimal process parameters of titanium vacuum brazed joints.

【 授权许可】

Unknown