微米级硬膜软基系统在划痕试验中的破坏方式

Failure Mode of Micron-thickness Hard Coatings on Soft Substrate in Scratch Test

通过磁控溅射方法在不锈钢基底上沉积了不同厚度的硬质钛-硅-氮膜、氮化钛膜、碳化钛膜和类金刚石碳膜,并进行了划痕试验。结果表明:微米级厚层硬质膜的划痕试验呈现相同的规律,即划痕边缘在全过程中出现破裂和脱落,划痕中部先出现膜层弯折破裂,继而出现薄膜部分脱离基底,最后完全脱离基体;而亚微米级厚度类金刚石碳膜的划痕试验在加载早期就同时出现划痕中部的薄膜破裂和脱离,随后出现全部脱离;声发射讯号尖峰的强度、频率与微米级硬质膜破裂和脱落的程度有很好的对应关系,而与亚微米级膜则无此对应关系。

Hard coatings of 1-3 μm thickness,like DLC,TiC,TiN and Ti-Si-N,were prepared by magnetron sputtering on soft stainless steel substrates.They failed in the same way during the scratch test,i.e.,along the brim of scratch,cracking and spalling took place throughout the test,but at the center,cracking appeared first,then partial spalling and finally massive spalling occurred.In contrast,for submicron-thickness(0.5μm) DLC coatings,cracking and spalling occurred at the center appeared from the very beginning of t...