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

用不同直径的2R球形压头进行了循环球形压痕试验，研究了陶瓷薄膜的裂纹萌生、磨损过程和分层，得到了外加最大载荷P&lt；max&gt；对薄膜裂纹萌生循环次数N_i的影响。主要结论如下：(1)环状裂纹萌生的载荷低于静态球面压痕试验得到的环状裂纹萌生载荷。(2)环状裂纹萌生后，薄膜在接触区内发生磨损，并发生剥离。(3)通过测量接触区的横截面形状可以定量评估磨损。(4)P&lt；max&gt；N_I关系具体取决于球形压头2R的直径。(5)2R的影响。在薄膜σ&lt；sr&gt；，i和N_i之间的关系上，I和N_i小于P&lt；max和gt；。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.