The composition of martensite transformation in NiAl alloy is determined using pure nickel and aluminum powder by vacuum hot press powder metallurgy, which is a composition of martensitic transformation, and the characteristics of martensitic transformation and microstructure of sintered NiAl alloys are investigated. The produced sintered alloys are presintered and hot pressed in vacuum; after homogenizing heat treatment at 1,273 K for 86.4 ks, they are water-cooled to produce NiAl sintered alloys having relative density of 99 % or more. As a result of observations of the microstructure of the sintered NiAl alloy specimens quenched in ice water after homogenization treatment at 1,273 K, it is found that specimens of all compositions consisted of two phases and voids. In addition, it is found that martensite transformation did not occur because surface fluctuation shapes did not appear inside the crystal grains with quenching at 1,273 K. As a result of examining the relationship between the density and composition after martensitic transformation of the sintered alloys, the density after transformation is found to have increased by about 1 % compared to before the transformation. As a result of examining the relationship between the hardness (Hv) at room temperature and the composition of the matrix phase and the martensite phase, the hardness of the martensite phase is found to be smaller than that of the matrix phase. As a result of examining the relationship between the temperature at which the shape recovery is completed by heating and the composition, the shape recovery temperature is found to decrease almost linearly as the Al concentration increases, and the gradient is about -160 K/ at% Al. After quenching the sintered NiAl alloys of the 37 at%Al into martensite, specimens fractured by three-point bending at room temperature are observed by SEM and, as a result, some grain boundary fractures are observed on the fracture surface, and mainly intergranular cleavage fractures.

Abstract
1.서 론
2. 실험방법
3. 결과 및 고찰
    3.1 예비소결
    3.2 소결체 조직
    3.3 마르텐사이트변태에 대한 밀도변화
    3.4 마르텐사이트변태에 따른 경도변화
    3.5 형상기억효과와 변태온도의 조성의존성
    3.6 파면 관찰
4. 결 론
References

• 한창석(호서대학교 자동차ICT공학과) | Chang-Suk Han (Dept. of ICT Automotive Engineering, Hoseo University) Corresponding author
• 진성윤(호서대학교 자동차ICT공학과) | Sung-Yooun Jin (Dept. of ICT Automotive Engineering, Hoseo University)
• 권혁구(호서대학교 환경공학과) | Hyuk-Ku Kwon (Dept. of Environmental Engineering, Hoseo University)