Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : October 08, 2016 - October 10, 2016
Titanium alloy (Ti-6Al-4V) with bimodal “harmonic structure”, which consists of a coarse-grained structure surrounded by a network structure of fine-grains, was produced by sintering mechanically milled powder to achieve high strength and good plasticity. In this study, we examine the behavior of small fatigue crack initiation and propagation of Ti-6Al-4V alloy with harmonic structure. In the material with harmonic structure, fatigue crack growth rate (da/dN) was high and threshold stress intensity range (ΔKth) was low compared to the material with coarse acicular structure. On the other hand, the material with harmonic structure showed higher fatigue limit. This is because the fine-grained microstructure, which shows high fatigue strength, is formed in the harmonic structure. However, their fatigue crack growth resistance was lower compared to the coarse-grained microstructure.
