Stress-induced martensitic phase transformations in polycrystalline CuZnAl shape memory alloys under different stress states
- Univ. of Illinois, Urbana, IL (United States). Dept. of Mechanical and Industrial Engineering
The effect of different uniaxial and triaxial stress states on the stress-induced martensitic transformation in CuZnAl was investigated. Under uniaxial loading, it was found that the compressive stress level required to macroscopically trigger the transformation was 34% larger than the required tensile stress. The triaxial tests produced effective stress-strain curves with critical transformation stress levels in between the tensile and compressive results. It was found that pure hydrostatic pressure was unable to experimentally trigger a stress-induced martensitic transformation due to the large pressures required. Traditional continuum-based transformation theories, with transformation criteria and Calusius-Clapeyron equations modified to depend on the volume change during transformation, could not properly predict stress-state effects in CuZnAl. Considering a combination of hydrostatic (volume change) effects and crystallographic effects (number of transforming variants), a micromechanical model is used to estimate the dependence of the critical macroscopic transformation stress on the stress state.
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
- DOE Contract Number:
- FG02-93ER14393
- OSTI ID:
- 616432
- Journal Information:
- Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 3 Vol. 29; ISSN MMTAEB; ISSN 1073-5623
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of stress state on the stress-induced martensitic transformation in polycrystalline Ni-Ti alloy
Stress-state effects on the stress-induced martensitic transformation of carburized 4320 steels