Improving strength-ductility synergy in a TRIP metastable β-Zr alloy containing heterogeneous α precipitates

• DOI: 10.1016/j.jmrt.2023.04.210
• Publication Date: 2023-05-01T01:20:46Z
• Authors: Zhongni Liao; Wei Fu; Tao Liu; Qi Sun; TaoTao Wang; Lizhai Zhang; Ran Jing; Tao Tao Ai; Jinyu Zhang
• Keywords: Ductility (Earth science); Diffusionless transformation; Metastability

In this study, a simple two-step heat treatment is proposed to design TRIP metastable β-Zr alloy with good strength-ductility synergy by introducing heterogeneous α precipitates. The precipitates mainly consist of necklace-like at β grain boundaries and small amount randomly distributed intragranular α. Compared the sample consisting single phase yield strength 683 MPa ductility 14.6%, designed two samples increases 781 842 respectively, while 15.3% decreases 13.6% respectively. microstructure analysis shows that dominant deformation mechanisms containing are α′ martensitic transformation domaination martensite, accompanied kinking band, {101¯1}α′ twinning. For precipitates, precipitation will increase triggering stress resulting in an early stage deformation. More importantly, unique structure brings gently cutting effect on grains traversability growing making martensite slightly inhibited, together absorption transfer plastic energy endow high ductility. present work can provide inspiration for improving or β-Ti through precipitate design.