Effect of cyclic heat treatment parameters on the grain refinement of Ti-48Al-2Cr-2Nb alloy

This work presents the influence of individual parameters of a cyclic heat treatment, i.e. upper cycle temperature, heating and cooling rates between room temperature and an upper temperature and number of cycles, on the grain refinement of a Ti-48Al-2Cr-2Nb alloy. The grain size as determined by the value of the average plane section diameter and indices describing its distribution (standard deviation) is sufficient to define grain refinement when the refinement obtained as a result of the treatment concerns the whole section of a sample. In the event when the refinement process only takes place partially or locally it becomes necessary to present distributions of the grain plane section area as a function of the frequency of occurrence and area fraction. The paper presents a possible mechanism of grain refinement of Ti-48Al-2Cr-2Nb alloy. The use of cyclic heat treatment provides an increase in the mechanical parameters of the alloy.