Microstructural design of two-phase titanium alloys by micro-scale strain distribution

Micro-scale strain distribution, an integrated response of microstructural parameters, is crucial to designing the microstructure of two-phase titanium alloys. In this paper, a microstructure-based finite element model is used to analyze the effect of microstructural parameters, such as volume fraction and distribution of primary α (αp), yield stress of transformed β (βt) on micro-scale strain distribution of two-phase titanium alloys. Strain distribution factor (SDF) is proposed to quantitatively characterize the strain distribution. It is found that with increasing SDF the homogeneity of strain distribution increases. Decreasing yield stress of βt and increasing volume fraction of αp will increase SDF, whereas directional distribution of αp will significantly decrease SDF. An SDF window for different αp volume fractions and βt yield stress is constructed, guiding the microstructural design of two-phase titanium alloy.