Finite Element Analysis of Cavitating Facet Interaction in a Fully Lamellar Titanium Aluminide Alloy under Creep Conditions

摘要

Creep constrained grain boundary cavitation in afully lamellar(FL) Form of a titanium aluminide intermetallicalloy has been studied using finite element(FE) TECHNIQUES.Tow different forms of FL models were considered. Cavitationwas modeled in the presence of grain boundary sliding (GBS)for the case of straight formerγgrain boundaries. Modeled ofcavitation without GBS were also performed for aFlmicrostructure with serrated former γgrain boundaries.The effect of cavitating facet interaction on rupturelife has been studied. A comparison between the FL formsand a dualphase equiaxed microstructure having the samephase ratio(α2 /γ)was also made to examine therelative susceptibility of these microstructures tohigh-temperature damage. It has been observed that theoverall effect of interaction between cavitatingfacets increases the rupture time significantly whenthese facets are on adjacent grains. However, in thepresence of GBS, cavitation on the facet with narrowerseparation effectively reduces the cavity growth rateon the facet with wider separation.