Transactions of Materials and Heat Treatment

Title：Study on the correlation of flow behavior and microstructure evolution during the high temperature tensile deformation of TC4 alloy

Authors： Li Bo Zhang Pei

Unit： The First Aircraft Design Institute of AVIC

KeyWords： titanium alloy TC4 flow stress strain rate sensitivity exponent strain hardening exponent microstructure evolution

ClassificationCode：TG319

year,vol(issue):pagenumber：2015,40(6):108-115

Abstract：

The influences of processing parameters on flow stress, strain rate sensitivity exponent, strain hardening exponent and microstructure evolution were investigated based on high temperature tensile test under the constant strain rate and microstructure examination of titanium alloy TC4, and the correlation of flow behavior and microstructure evolution was obtained. The results show that the local necking will appear and lead to crack at deformation temperatures 1123-1213 K, strain rate 0.1 s-1 and the strain within 0.7, and the maximum m value occurs at deformation temperature 1183 K and strain rate 0.01 s-1 because the microstructure of primary α phase is fine and equiaxed grain. However, the strain hardening exponent decreases with the increase of strain at strain rate 0.01 s-1 due to the combination with work hardening and thermal softening. The morph of primary α phase changes from strip to equiaxed grain with the increase of deformation temperature, and it is of slight oriented characteristic with the increase of strain rate, which is not beneficial for the grain boundary sliding and rotation. The influence of strain on the morph and volume fraction of primary α phase is less, but it is significant for secondary α phase.

Funds：

李波（1981-），女，硕士，工程师

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