CVD金刚石膜断裂性能测试装置的研究

TESTING RIG FOR FRACTURE PROPERTIES OF CVD DIAMOND FILMS

文章介绍了一种利用恒载荷速率加载测试金刚石膜断裂性能的试验方法 ,并建立了国内第一台金刚石膜断裂性能测试的专用装置 .该装置利用弹性压头代替传统的刚性压头 ,可以成功地解决断裂试验的缓慢加载问题 .试验装置的最大载荷为 5 0 0N ,可以在 5— 5 0 0N之间获得准确的载荷 ,误差不大于 1% .最小加载速率为 0 5N s,最大加载速率为 2 5N s.该装置采用计算机控制 ,可以直接输出试验结果 .该装置采用恒载荷速率 (0 5N s至 2N s)的加载方式测得的断裂性能比用恒位移速率 (0 5mm min和 0 0 5mm min)加载方式测得的断裂性能更低 ,更适合高脆性。

New Experimental methods for measuring the fracture properties of CVD diamond films are discussed. A special computerized testing rig has been invented which can operate at constant loading rate. The computer controlled device substitutes an elastic pressure sensitive loading fixture for a rigid structure and successfully solves the difficulty of loading slowly. The lowest applicable loading rate is 0 5N/S, the highest is 25N/S. The maximum load is 500N and error is lower than 1%. Our testing device can measure fracture properties lower than those tested by a loading method with a constant displacement rate. The device is suitable for CVD diamond films, which are highly brittle and of small dimension (length×width 10mm×2mm, thickness 0 25—1mm).