Elastoplastic response of as-built SLM and wrought Ti-6Al-4V under symmetric and asymmetric strain-controlled cyclic loading. Issue 9 (12th November 2018)

• Record Type: Journal Article
• Authors: Agius, Dylan; Kourousis, Kyriakos I.; Wallbrink, Chris
• Is Part Of: Rapid prototyping journal. Volume 24:Issue 9(2018)
• Page Start: 1409
• Page End: 1420
• Publication Date: 2018-11-12
• Subjects: Advanced manufacturing technologies -- Mechanical properties -- Mechanical properties of materials -- Titanium -- Modelling -- Tests; Engineering design -- Periodicals; 620.004205
• DOI: 10.1108/RPJ-05-2017-0105
• Languages: English
• ISSNs: 1355-2546

Abstract

Abstract : Purpose: The purpose of this paper is to examine the mechanical behaviour of additively manufactured Ti-6Al-4V under cyclic loading. Using as-built selective laser melting (SLM) Ti-6Al-4V in engineering applications requires a detailed understanding of its elastoplastic behaviour. This preliminary study intends to create a better understanding on the cyclic plasticity phenomena exhibited by this material under symmetric and asymmetric strain-controlled cyclic loading. Design/methodology/approach: This paper investigates experimentally the cyclic elastoplastic behaviour of as-built SLM Ti-6Al-4V under symmetric and asymmetric strain-controlled loading histories and compares it to that of wrought Ti-6Al-4V. Moreover, a plasticity model has been customised to simulate effectively the mechanical behaviour of the as-built SLM Ti-6Al-4V. This model is formulated to account for the SLM Ti-6Al-4V-specific characteristics, under the strain-controlled experiments. Findings: The elastoplastic behaviour of the as-built SLM Ti-6Al-4V has been compared to that of the wrought material, enabling characterisation of the cyclic transient phenomena under symmetric and asymmetric strain-controlled loadings. The test results have identified a difference in the strain-controlled cyclic phenomena in the as-build SLM Ti-6Al-4V when compared to its wrought counterpart, because of a difference in their microstructure. The plasticity model offers accurate simulation of the observed experimental behaviour in the SLM material. Research limitations/implications: Further investigation through a more extensive test campaign involving a wider set of strain-controlled loading cases, including multiaxial (biaxial) histories, is required for a more complete characterisation of the material performance. Originality/value: The present investigation offers an advancement in the knowledge of cyclic transient effects exhibited by a typical α' martensite SLM Ti-6Al-4V under symmetric and asymmetric strain-controlled tests. The research data and findings reported are among the very few reported so far in the literature.