Tensile properties and microstructure of Ti14 alloy after semi-solid forging

Abstract

Tensile properties of a new α+Ti 2Cu alloy after solid forging at 950 °C and semi-solid forging at 1 000 °C and 1 050 °C were investigated over the temperature range of 20–600 °C. The results reveal that high strength and low ductility are obtained in all semi-solid forged alloys. Tensile properties decrease as the semi-solid forging temperature increases, and cleavage fractures are observed after semi-solid forging at 1 050 °C. The variations in tensile properties are attributed to the coarse microstructures obtained in the semi-solid alloys. It is found that the elevated semi-solid temperatures lead to more liquid precipitates along the prior grain boundaries, which increases the peritectic precipitation and formation of Ti 2Cu precipitation zones during re-solidification. Recrystallization heat treatment leads to fine microstructure of semi-solid forged alloys, resulting in improvement of tensile properties.