Effect of heat treatment on morphology evolution of Ti2Ni phase in Ti-Ni-Al-Zr alloy

2017 International Symposium on Application of Materials Science and Energy Materials

材料科学;能源学

Sheng, Liyuan^1 ; Yang, Yang^1 ; Xi, Tingfei^1

Shenzhen Institute, Peking University, Shenzhen, China^1

关键词: Binary phase diagrams;    Effect of heat treatments;    Eutectic structures;    Eutectoid structure;    Microstructure observation;    Morphology evolution;    Phase transformation temperature;    Ti-Al-Zr alloys;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/322/2/022040/pdf
DOI  :  10.1088/1757-899X/322/2/022040

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The Ti6Al2Zr alloy with 15 wt.% Ni addition was prepared and then heat treated in the research. The microstructure of the alloy and evolution of Ti2Ni precipitate were investigated. The microstructure observations demonstrate that the Ni addition could promote the formation of eutectoid and eutectic structures in Ti-Al-Zr alloy. In the eutectoid structure, the ultrafine Ti2Ni fiber precipitates in the α-Ti matrix, but in the eutectic structure, the fine α-Ti phases precipitate in the Ti2Ni matrix. The heat treatment could change the morphology of Ti2Ni precipitates by thinning, fragmenting, merging and spherizing. In the alloy heat treated at and below 1073K, the coarsening of α-Ti precipitates in eutectic structure and Ti2Ni precipitates in eutectoid structure is the mainly characteristic. In the alloy heat treated above 1073K, the phase transformation of α to β phase is the main characteristic, which changes the morphology and amount of Ti2Ni phase by the solid solution of Ni. The phase transformation temperature of Ti-Ni-Al-Zr alloy is between 1073-1123K, which is increased compared with that of the Ti-Ni binary phase diagram.