中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2014年
12期
3082-3087
,共6页
NiTi合金%双程形状记忆效应%临界应变%应变分布%压痕
NiTi閤金%雙程形狀記憶效應%臨界應變%應變分佈%壓痕
NiTi합금%쌍정형상기억효응%림계응변%응변분포%압흔
NiTi alloy%two-way shape memory effect%critical strain%strain distribution%indentation
利用维氏四棱锥压痕方法，通过温度控制在NiTi合金中获得凸起?平整的双程形状记忆效应表面。通过研磨剥层法，发现随着消除深度的增加所获得的凸起高度和直径减小，在消除160μm深度后，表面凸起现象消失，并从理论上定量分析该深度所对应的临界应变大小。实验表明：双程形状记忆效应是通过对形状记忆合金进行温度?应变循环变形而获得。因此，可能存在一定的临界应变，在低于该应变时，材料不能表现双程形状记忆效应。
利用維氏四稜錐壓痕方法，通過溫度控製在NiTi閤金中穫得凸起?平整的雙程形狀記憶效應錶麵。通過研磨剝層法，髮現隨著消除深度的增加所穫得的凸起高度和直徑減小，在消除160μm深度後，錶麵凸起現象消失，併從理論上定量分析該深度所對應的臨界應變大小。實驗錶明：雙程形狀記憶效應是通過對形狀記憶閤金進行溫度?應變循環變形而穫得。因此，可能存在一定的臨界應變，在低于該應變時，材料不能錶現雙程形狀記憶效應。
이용유씨사릉추압흔방법，통과온도공제재NiTi합금중획득철기?평정적쌍정형상기억효응표면。통과연마박층법，발현수착소제심도적증가소획득적철기고도화직경감소，재소제160μm심도후，표면철기현상소실，병종이론상정량분석해심도소대응적림계응변대소。실험표명：쌍정형상기억효응시통과대형상기억합금진행온도?응변순배변형이획득。인차，가능존재일정적림계응변，재저우해응변시，재료불능표현쌍정형상기억효응。
Two-way shape memory effect (TWSME) surface in NiTi was obtained using Vickers four-sided pyramidal indentation method, namely, the switchable surface between protrusions and flat state controlled by temperature. By gradual grinding off the deformed layer after indenting, the diameter and height of the protrusions decrease as increasing the removal layer. It is found that no protrusions are observed after 160 μm thick layer was removed. The critical microstrain at this depth is further theoretically calculated. It shows that TWSME can be obtained by means of thermomechanical training in shape memory alloys. Thus, there probably exists a critical microstrain, below which no TWSME will occur.
