Abstract: The preparation of TC4 alloy by powder NNS-HIP has received widespread attentions in recent years due to its unique advantages. In this research, effects of hot isostatic pressing temperature on the microstructure and tensile properties of TC4 alloy were systematically investigated. The experimental results show that the alloy is completely densified when the holding temperature reaches 800 ℃ under the holding pressure condition of 120 MPa for 2 hours; As the holding temperature increases from 800 ℃ to 920 ℃, the tensile strength of the alloy decreases from 942 MPa to 920 MPa, and the tensile strain increased from 13.7% to 18.1%; The volume fraction of β phase in the alloy microstructure increases with the rise of the holding temperature, and the distribution of β phase tends to be uniform as a result. The addition in β phase is a key factor for the decline in strength and ascent in plasticity of the alloy.

Key words: TC4 alloy, hot isostatic pressing holding temperature, microstructure evolution, tensile properties