Phase transformation of NiTi alloys during vacuum sintering

5th International Conference on Nanomaterials and Materials Engineering

Wang, Jun^1 ; Hu, Kuang^2

School of Metallurgy and Material Engineering, Chongqing University of Science and Technology, University City, Shapingba District, Chongqing, China^1

School of Material Science and Engineering, Chongqing University, Chongqing, China^2

关键词: Atomic ratio;    NiTi alloys;    NiTi shape memory alloys;    Press forming;    Sintering temperatures;    Sintering time;    Ti powders;    Vacuum sintering;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/204/1/012023/pdf
DOI  :  10.1088/1757-899X/204/1/012023

来源: IOP

【 摘 要 】

The aim of this study is to ascertain the Phase transformation of NiTi alloys during vacuum sintering. NiTi shape memory alloys (SMA) of atomic ratio 1:1 were prepared through press forming and vacuum sintering with the mixture of Ni and Ti powders. Different samples were prepared by changing the sintering time and the sintering temperature. Phase and porosity of the samples were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that in the process of sintering NiTi2and Ni3Ti phases are formed firstly and then transform into NiTi phase. The quantity of NiTi2and Ni3Ti phases gradually decreased but not eliminate completely with increase of sintering time. The porosity of specimen sintering at 900°C decreases slightly with increase of sintering time. With increase of sintering time the porosity of specimen sintering at 1050°C decreased firstly and then increased because of generation rich titanium liquid in the process of sintering.