摘要
在Instron5848疲劳试验机对纯铜试样进行疲劳加载的同时,利用红外热像仪和远距视频显微镜,同步监测试样的表面温度场和微观形貌的变化规律.试验过程中观察到试样的表面温度场变化呈现三个阶段:初始快速上升阶段、平稳变化阶段和断裂前的急剧上升阶段.试验结果还表明:试样的自热温升依赖于加载频率和应力水平,与疲劳寿命的对数值呈线性关系.通过试样表面温度场和微观形貌的对比分析,发现热耗散在一定程度上反映了材料的损伤过程.
Using the infrared camera and long-distance video microscope,a test system was set up to on-line monitor the change of surface temperature and microstructure during fatigue. Fatigue tests were finished for smooth specimen of pure copper on Instron 5848 test machine. The temperature evolution measured by infrared camera indicates three stages：the initial rapid increase, the stable variation, and abrupt rise before failure. The results also show that the temperature increase, resulting from plastic deformation, de- pends on the applied stress and frequency,and the maximum temperature increase has a linear relation with the logarithm of the fatigue life. Through the comparison and analysis of surface temperature and microscopic form,it is also found that the thermal dissipation can reflect the damage process in a certain extent.
出处
《固体力学学报》
CAS
CSCD
北大核心
2008年第4期361-364,共4页
Chinese Journal of Solid Mechanics
基金
西北工业大学"英才培养计划"资助
关键词
疲劳
热耗散
红外热像
显微结构
fatigue, thermal dissipation, infrared thermography, microstructure
