薄膜涂层材料的界面破坏准则

The Interface Failure Criterion of Coating Materials

为了确定界面起裂位置及条件的评价方法,通过对引入假想界面裂纹的划痕实验的数值分析,讨论了界面的起裂位置.根据起裂位置的不同界面应力状态及相应的实验结果,提出了界面破坏的强度准则.实验和分析结果表明,在划痕实验中,起裂位置由最大界面剪应力决定,但起裂条件不仅与界面剪应力有关,而且与起裂位置处的界面压应力有关,界面压应力越大,导致界面起裂的界面剪应力也越大.该薄膜界面结合强度的评价准则,不受具体实验条件的影响,具有通用性.

The critical load measured by scratch tests is the most widely used parameter to characterize the strength behavior on the sense of comparison in engineering. The interface cracking position was discussed by numerical simulations of scratch tests with interfacial cracks. Based on different stress state at the cracking position and experimental results, an interface failure criterion was proposed. It is found that the cracking position is determined by the maximal interfacial shear stress, while the debonding condition depends both on the interfacial shear stress and compressive stress. With the increase of the interfacial compressive stress, the critical shear stress increases. Moreover, this failure criterion, which is independent of test conditions, can be applied in common.