摘要
残余应力是制约物理气相沉积(Physical vapor deposition,PVD)硬质薄膜厚度的关键因素。采用多弧离子镀技术在高速钢基体上制备了厚度从3.7mm到15.5mm的TiN薄膜,结合曲率法和有限元法研究残余应力及结合性能随膜厚的变化规律。结果表明,随着膜厚的增加,基片弯曲程度加剧,而薄膜平均残余应力降低;膜层内残余应力的整体水平决定了界面切应力大小,薄膜结合性能随界面切应力的增加而降低。增加基体偏压、降低工作气压均导致薄膜内部残余应力的升高。当残余压应力较高时,TiN薄膜具有细小、致密的柱状晶结构,并呈现(111)择优取向,薄膜硬度及断裂韧度较高,耐磨性能良好。研究结果提示我们,通过残余应力的调控可提高硬质薄膜的力学特性。
The residual stress is the key factor determining the thickness of PVD hard coatings. In present study, TiN coatings with thickness ranging from 3.7 mm to 15.5 mm are fabricated on high speed steel by multi-arc ion plating(MAIP). As the coating thickness increases, the curvatures of substrate become more pronounced yet the average residual stresses are decreased. Combining the substrate curvature method and finite element analysis(FEA), the dependences of residual stress and adhesion strength on coating thickness have been revealed. The larger interfacial shear stress is the main reason for the lower adhesion strength, which is determined by the integral residual stress over the coating thickness. It is also found that the residual stress is increased with increasing bias voltage and/or lowering the working pressure. The coating with the higher compressive residual stress exhibits a dense columnar structure and pronounced(111) orientation. And meanwhile, it owns the higher hardness, larger fracture toughness and favorable wear resistance. Above research results suggest that the mechanical properties of hard coatings can be improved through the residual stress modulation.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2017年第24期42-48,共7页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(51371136
51471130)
关键词
TIN薄膜
曲率法
残余应力
结合强度
力学性能
TiN coatings
curvature method
residual stress
adhesion strength
mechanical property
