【摘要】 为了解决SiC硬质膜力学性能难测试的问题,提出以Oliver-Pharr模型为基础的位移敏感压痕技术来评价SiC硬质膜的硬度及弹性模量。为了解其可靠性,将此方法用于普通玻璃和不锈钢作为参考。选用厚度为315±15μm的化学气相沉积(CVD)SiC硬质膜作为样品,实验以0.5N/s的载荷速度进行加卸载,载荷峰值取10～30N,结果表明:位移敏感压痕法计算出的普通玻璃和不锈钢的硬度分别为6.5GPa和1.7GPa,传统显微硬度计测试出的结果分别为5.3GPa和1.8GPa,其值比较接近;此方法计算出普通玻璃和不锈钢的弹性模量分别为65.1GPa和178.4GPa,与实际值70GPa和190GPa误差很小,因此表明该方法可靠性良好。利用位移敏感压痕技术得知CVDSiC硬质膜的硬度和弹性模量为37.7GPa和456.4GPa。另外根据维氏压痕形貌,应用JISR1607-1990标准,Anstis,Evans&Charles三断裂韧性公式,计算出普通玻璃和CVDSiC硬质膜KIC均值分别为0.78MPa.m1/2和2.70MPa.m1/2。此方法可广泛用于评价硬质膜的硬度和弹性模量等力学性能。更多还原

【Abstract】 To solve difficulties of mechanical properties test of SiC hard coating,depth-sensing indentation method was used to evaluate the hardness and elastic modulus of SiC hard coatings.Common glass and stainless steel are adopted in this test for comparing and to understand the reliability.CVD SiC hard coating with the thickness of 315±15 μm was used as the specimens.The loading-unloading speed was 0.5 N/s,and the maximum load was 10-30 N in this work.It was showed that calculated hardness of common glass and stainless steel were 6.5 GPa and 1.7 GPa,respectively,which were close to 5.3 GPa and 1.8 GPa measured by traditional micro-indentation,respectively;and calculated elastic modulus of common glass and stainless steel were 65.1 GPa and 178.4 GPa,respectively,which were approximately to actual value 70 GPa and 190 GPa,respectively.Therefore,these calculated results show the good reliability of this method.The calculated hardness and elastic modulus of CVD SiC hard coating were 37.7 GPa and 456.4 GPa using this method,respectively.Based on the Vickers indent and applied JISR1607-1990 standard,Anstis and Evans&Charles fracture toughness equations,the obtained mean values of KIC for common glass and CVD SiC hard coating were 0.78 MPa·m1/2 and 2.70 MPa·m1/2,respectively.This method can be widely used to evaluate hardness and elastic modulus of hard coatings.更多还原