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针对恶劣环境下MEMS对高强度材料的需求,采用化学气相沉积(CVD)外延生长3C-SiC薄膜.利用微力学操纵系统,对3C-SiC微悬臂梁进行了弯曲实验.利用厚板结构的有限元仿真和威布尔统计,得到3C-SiC薄膜断裂强度.结果表明:不同尺寸3C-SiC微悬臂梁威布尔特征强度为1 852.15 MPa、2 554.56 MPa、2 598.39 MPa、2 911.64 MPa,威布尔模数分别为9.547、11.541、18.909、20.733.断裂强度随微悬臂梁宽度增加而减小,威布尔模数也减小,分析认为:结构尺寸越大的微悬臂梁,含有的生长缺陷(如孔洞、裂纹等)越多,造成其断裂强度越低.
3C-SiC microcantilever was bent and grown by chemical vapor deposition (CVD) to deal with the demand of high-strength materials under harsh environment. The bending test of 3C-SiC microcantilever was carried out by using the micromechanical operating system. The results show that the Weibull characteristic strengths of 3C-SiC microcantilever with different sizes are 1 852.15 MPa, 2 554.56 MPa, 2 598.39 MPa, 2 911.64 MPa, Weibull’s modulus The number of cracks were 9.547, 11.541, 18.909 and 20.733, respectively. The fracture strength decreased with the increase of the microcantilever width and the Weibull modulus also decreased. The analysis shows that the microcosmic beam with larger structure size contains growth defects , Cracks, etc.), resulting in the lower the breaking strength.