Effects of Mo Addition on the Microstructure and Mechanical Properties of Ti45A15Nb0. 3Y Alloy

摘要

Effects of 0. 8～1. 4at % (in atomic fraction) Mo addition on the microstructure and mechanical properties of Ti45A15Nb0. 3Y alloy have been studied Small quantity of β phase distributes along grain boundaries as discontinuous network in Ti45Al5NbXMo0. 3Y alloys owing to Mo segregation. With the increase of Mo content, the β blocks form on grain boundaries when Mo addition exceeds 0. 8at. % and the y grains occur when the Mo addition reaches 1. 2at. %. The (3 phase can be eliminated by uniform heat treatment when the Mo content is below lat. %. With the increase of Mo content,yield strength (YS) and ultimate compression strength (UCS) first increase and then decrease. However,the maximum compression deformation to failure (Emax)increases with increasing Mo content at room temperature. Therefore,the content of Mo element should be controlled in the vicinity of lat. % for Ti45Al5Nb0. 3Y alloy for avoiding reduction of creep resistance and promoting other mechanical properties.