邻苯二甲酸二甲酯晶体中裂纹愈合效应的力学谱研究  

Study of crack healing effect in dimethyl phthalate crystals by mechanical spectroscopy

作　　者：周恒为[1,2] 王丽娜[1] 郭秀珍[1] 吴娜娜[1] 张丽[1] 张晋鲁[1,2] 黄以能[1,2] 

机构地区：[1]伊犁师范学院新疆凝聚态相变与微结构重点实验室,伊宁835000 [2]南京大学物理系国家固体微结构重点实验室,南京210093

出　　处：《物理学报》2010年第3期2120-2125,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10774064,30860076);新疆自治区教育厅重点基金(批准号:XJEDU2007137);新疆自治区科技厅自然基金(批准号:200821104,200821184)资助的课题~~

摘　　要：推广应用应力诱导裂纹和裂纹愈合的新方法(RMS-CH方法,Wu等,Appl.Phys.Lett.92011918-1(2008))于晶体材料的应力诱导裂纹和裂纹愈合过程的实时检测.对邻苯二甲酸二甲酯晶体的测量结果表明,在定升温速率条件下:1)裂纹愈合的速率随温度变化表现为较为尖锐的单峰,对应的峰温可以作为裂纹愈合的特征温度Tcch,且Tcch=206K;2)裂纹愈合速率峰是不对称的,低温边宽而高温边窄,即裂纹愈合在相对低的温度就已经开始,并且低于Tcch的愈合量占总愈合量的比例较大.上述结果与玻璃材料中的裂纹愈合行为极为相似,但是Tcch比邻苯二甲酸二甲酯玻璃的裂纹愈合温度高一些.另外,Tcch远低于晶体的熔化温度,表明其与正常的结晶过程有很大的不同.值得指出的是,观测到对应于晶体裂纹愈合过程的两个动力学损耗峰,可以预期这对晶体裂纹愈合机理的研究无疑是有益的.上述结果也表明了RMS-CH方法对晶体裂纹产生和愈合过程实时检测的可行性和有效性.The recently developed method to detect the stress-cracking and crack healing of glasses in real-time （called the RMS-CH in short,Wu et al.,Appl. Phys. Lett. 92,011918-1（2008）） is applied to the detections of crystals . The experimental results of dimethyl phthalate crystal indicate that,under the condition of constant heating rate：1） the crack-healing rate shows a sharp peak as a function of temperature,the peak temperature can be taken as the chara cteristic temperature T^c_ch of the crack-healing ,and T^c_ch=206 K;2） the peak is not symmetric,and the low temperature side is wider than the high temperature side,which means that the crack-healing has started at lower temperatures and the amount of healing below T^c_ch is more than that above T^c_ch. This behavior is similar to that in glasses,but T^c_ch is higher than that of glassy state. Moreover,T^c_ch is much lower than the melting point of the crystal,which indicates that the crack-healing mechanism is quite different from that of recrystallization. We would like to point out that two dynamical loss peaks related to the crack-healing process are observed for the first time,which will be helpful to the unders tanding of the mechanisms. The above results also show the feasibility and validity of the RMS-CH method to investigate the stress-cracking and crack-healing in crystals as in glasses.

关 键 词：裂纹愈合 晶体缺陷 力学谱 

分 类 号：O346.1[理学—固体力学]