Optimization of pressure-less microwave sintering of Ti6Al4V by response surface methodology

Abstract

ABSTRACTPressure-less microwave sintering of titanium alloy (Ti6Al4V) is an economical and viable solution for obtaining near net shape fabrication of complex shapes. Input process parameters such as sintering temperature (St), heating rate (Hr), and holding (Ht) were optimized in this work for maximal compressive yield strength, maximal density, and minimal volumetric shrinkage by response surface methodology (RSM). The individual and interactive influence/effects of the process parameters on each of the responses were studied. A statistical model was developed to predict each of the output responses. Analysis by X-ray diffractometry indicates the presence of alpha and beta phase Ti6Al4V. The optimal sintering parameters identified were: St of 1280°C, Hr of 8°C/minute, and Ht of 78 minutes. At the optimized parameters, a compressive yield strength of 541.34 ± 48.81 MPa, density of 4022.59 ± 87.38 kg/m3, and volumetric shrinkage of 16.86 ± 5% were obtained. The results of this study will help rapidly manufacture higher-strength titanium customized components using pressure-less microwave sintering method.