Development of cyclic sphere indentation test to evaluate the strength of ceramic thin film deposited on the substrate

采用不同直径2R的球形压头进行循环球压痕试验，研究了陶瓷薄膜裂纹萌生、磨损过程和分层等方面的变化，得到了最大载荷P_<max>对薄膜裂纹萌生循环数N_i的影响。主要结论如下。(1)与静态球压痕试验得到的环裂纹起裂载荷相比，环裂纹在较低载荷下起裂。(2)环裂纹产生后，接触区域内薄膜发生磨损，薄膜发生分层。(3)通过测量接触面积的横截面形状，可以定量评价磨损情况。(4) P_<max>。N_i关系具体取决于球形压头2R的直径。(5) 2R效应。薄膜的拉伸应力σ_<sr>、i和N_i之间的关系小于P_<max>。N_i关系。

Cyclic sphere indentation tests were carried out by using spherical indenters of varying diameter 2R to investigate the aspects of crack initiation, wear progress, and delamination in ceramic thin film and to obtain the influence of the applied maximum load P_<max> on the cyclic number of crack initiation N_i in thin films. The main conclusions are the following.(1) Ring crack initiate at the lower load than that of a ring crack initiation load obtained by static sphere indentation test.(2) After ring crack initiate, wear of film progresses inside the contact area, and delamination in thin film occur.(3) Quantitative evaluation of wear is possible by measuring the cross-sectional shape of contact area.(4) The P_<max>. N_i relationships specifically depend on the diameter of spherical indenter 2R.(5) The effect of 2R. on the relationship between tensile stress of filmσ_<sr>, i and N_i is smaller than that of the P_<max>. N_i relationship.