Martensite transformation of 50Ni-xhf(50-x)Ti shape memory alloys
The characteristics of martensite transformation in NiTi-Hf alloys, such as transformation temperature, enthalpy and entropy changes, hysteresis width, Young`s modulus and damping, and martensite structure, are investigated in this paper. The results indicate that: (1) The martensite of the NiTi-Hf alloys is thermoelastic martensite. (2) The transformation temperatures and thermodynamic parameters depend on the Hf content. (3) The crystal structure of the high temperature parent phase is of the CsCl-type, regardless of the alloy composition. The primary product of the martensite transformation at room temperature for alloys with x < 6 is monoclinic B19` martensite, while for 20< x <30 at%, the crystal structure is orthorhombic B19.
- Research Organization:
- Florida International Univ., Miami, FL (United States)
- OSTI ID:
- 253904
- Report Number(s):
- AD-A-303906/2/XAB; CNN: Contract DAAL03-91-G-0245; TRN: 61630135
- Resource Relation:
- Other Information: PBD: 17 Nov 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
Structure and substructure of martensite in a Ti{sub 36.5}Ni{sub 48.5}Hf{sub 15} high temperature shape memory alloy
Martensite aging effect in a Ti{sub 50}Pd{sub 50} high temperature shape memory alloy