Effect of Multi-pass Deformation on Microstructure Evolution of Spark Plasma Sintered Ti-6Al-4V Alloy.

In this paper, the microstructure of Ti-6Al-4V alloy sintered by spark plasma was studied by multi-pass of hot compression experiment, and the influence of different thermal deformation parameters (hot compression temperature deformation: 950°C–20% for one pass, 850°C–20% for two passes and 900°C–10%/20%/30% for three passes) was studied. The results show that the dynamic recrystallization characteristic behavior appears in the three deformation passes. The microstructure after the first and second pass deformation is mainly composed of Widmanstätten structure. With the increase of strain rate, the thickness of lamellar α decreases gradually. In three pass, the grain boundary α phase and the layered α phase are twisted and bent when the deformation amount is 10% and 20%, and the deformation amount increases to 30%. The spheroidization of lamellar α phase occurs, and the size of β grain decreases obviously. The content of equiaxed α phase and grain size decrease with the increase of strain rate. [ABSTRACT FROM AUTHOR]