| Popis: |
The mechanical and magnetic properties of magnetostrictive materials are susceptible to high temperature. However, the failure mechanisms and magnetism-related deterioration remain elusive. In this study, the Fe71Ga29 alloys subjected to 0 h, 2 h, 10 h and 32 h-thermal treatment under 573 K were comparatively investigated to quantitatively evaluate the contributions of thermal-treatment time. The hardness fist increases to a maximum value (4.327 GPa) and then decreases with rising temperature. Different from as-cast sample, the thermal-treatment samples show Fe–O structure. The formation of Fe–O give rise to a distinctive variational tendency of coercivity, namely, the coercivity fist decreases and then increases with rising temperature. Another series of as-cast samples were subjected to thermal treatment at 393 K, 418 K, 443 K and 468 K for 2 h, which were performed to analyze the contributions of thermal-treatment temperature. Especially, the hardness was enhanced monotonically and magnetic properties were weakened monotonically with extending the time of thermal treatment. |
