Metallographic Characterization and Fatigue Damage Initiation in Ti6Al4V Alloy Produced by Direct Metal Laser Sintering

Abstract:

Direct Metal Laser Sintering (DMLS) is a complex process where a part is build-up by localized melting of gas atomized powder layers by a concentrated laser beam followed rapid solidification. The microstructure of DMLS produced material is substantially different from that of conventionally manufactured materials, although the ultimate strength is similar. However, yield strength and elongation and especially fatigue behavior may vary considerably according to the process parameters and post fabrication heat treatment because they affect structural heterogeneity, porosity content, residual stresses, and surface conditions. Fatigue tests of DMLS Ti6Al4V alloy are interpreted in the light of a thorough metallographic and fractographic investigation. The fatigue crack initiation for three different cyclic stress directions with respect to build direction is determined by fractography.

• Periodical: Materials Science Forum (Volume 891)
• Pages: 311-316
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.891.311
• Online since: March 2017
• Authors: Radomila Konečná*, Gianni Nicoletto, Adrián Bača, Ludvík Kunz
• Keywords: Crack Initiation, DMLS, Fatigue Damage, Microstructure, Ti6Al4V

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