Nano-impact test on PVD-coatings with graded mechanical properties for assessing their brittleness

作者：Bouzakis K D^*; Skordaris G; Gerardis S; Bouzakis E

来源：Materialwissenschaft und Werkstofftechnik, 2013, 44(8): 684-690.

DOI：10.1002/mawe.201300176

• PVD films
• micro-blasting
• brittleness
• FEM simulation

In the described investigations, nano-impact tests were conducted on PVD films with graded mechanical properties. The properties gradation was induced by micro-blasting at different pressures for constant duration. Micro-blasting improves the film mechanical properties due to the induced residual compressive stresses into the coating structure. The film mechanical properties as well as the ratio of the film yield to rupture stress (S-Y/S-M) grow up to a certain micro-blasting pressure. The augmentation of S-Y/S-M ratio increases simultaneously the film brittleness. For analyzing the effect of the S-Y/S-M ratio on the film brittleness, a multi-layer 3D-FEM model simulating the nano-impact test was developed employing the LS-DYNA software package. The FEM calculated results converge sufficiently with the attained experimental ones. Based on these results, the film%26apos;s failure initiation and evolution can be predicted depending on the S-Y/S-M ratio of the individual film layers.

• 出版日期2013-8