Utilization of a microstructure sensitive fatigue model for additively manufactured Ti-6Al-4V

• Main Author: Torries, Brian A.
• Other Authors: Nima Shamsaei
• Format: Others
• Language: en
• Published: MSSTATE 2016
• Subjects: Mechanical Engineering
• Online Access: http://sun.library.msstate.edu/ETD-db/theses/available/etd-11092016-182738/

<p>The trustworthiness of AM metallic materials is not well characterized. Therefore, fatigue models that consider the unique microstructure and porosity inherent to AM parts are needed. Herein, a microstructure-based fatigue model is calibrated for use in predicting fatigue life of additively manufactured (AM) Ti-6Al-4V. Various Ti-6Al-4V samples, with variations in porosity, were fabricated using Laser Engineered Net Shaping (LENS), a Direct Laser Deposition method. LENS samples in the as-built and heat treated conditions, together with wrought Ti-6Al-4V samples, underwent fatigue testing, as well as microstructure and fractographic inspection. The collected microstructure/defect statistics were used for calibrating a microstructure-sensitive fatigue model. LENS Ti-6Al-4V sample fatigue lives were found to be consistently less than those of the wrought Ti-6Al-4V samples, due to the presence of pores/defects within the LENS material. Results further indicate that fatigue life predictions from the employed model were in close agreement with experimental results.</p>