Monotonic and Fatigue Behavior of EBM Manufactured Ti-6Al-4V Solid Samples: Experimental, Analytical and Numerical Investigations

Materials (Basel). 2020 Oct 17;13(20):4642. doi: 10.3390/ma13204642.

Abstract

The present study aims to carry out an experimental, analytical and numerical investigation of the monotonic and fatigue performance of electron beam melted Ti-6Al-4V structures. Therefore, tensile tests, multiple step tests and strain-life tests were performed on machined EBM Ti-6Al-4V solid samples. An elastic-plastic material model in combination with a numerical damage model was examined according to the experimental tensile tests. Analytical models proposed by Ramberg and Osgood, as well as Coffin and Manson were obtained to describe the cyclic stress-strain curves and strain-life curves, respectively. The fracture surfaces of the tested samples and the influence of different build directions were analyzed. A prediction of the static and fatigue material properties is of particular importance, e.g., for the safe application of additively manufactured load-bearing implant structures. Based on the determined analytical and numerical models, the material and product behavior of complex electron beam melted structures under cyclic loading and fatigue life determination can be investigated in the early stages of the product development process.

Keywords: Coffin–Manson model; Johnson–Cook failure model; Ramberg–Osgood model; Ti-6Al-4V; electron beam melting; monotonic and cyclic stress-strain behavior; strain-life test.