Development of a Life Prediction Model of Ti-6Al-4V obtained by Additive Manufacturing

Abstract

The present study aimed to develop a new life prediction model of a Ti-6Al-4V alloy obtained by additive manufacturing (AM). The Selective Laser Melting (SLM) method was used to obtain specimens. This study contemplates four phases. The first phase encompasses an analysis of the manufacturing process, including the raw materials cycle, specimen design, and the cutting process. In the second phase, tensile and fatigue tests are conducted to obtain the elastic and plastic proprieties and fatigue parameters (S-N Curve). The third phase involves an analytical and quantitative study of the manufacturing intrinsic defects of the SLM process, using optical microscopy, micro and nanotomography, and image treatment. The last phase focused on developing a life prediction model for Ti-6Al-4V based on experimental findings from the preceding steps. In conclusion, Ti-6Al-4V alloy obtained by additive manufacturing showed better overall mechanical properties when compared to the same alloy produced by a traditional method, exhibiting robust plastic behaviour and good ductility. Concerning life prediction models, two new models were developed to predict the fatigue limit of a Ti-6Al-4V obtained by additive manufacturing based on two different defect quantification methods.