Transitions of Film/Substrate Specimens during Nanoindentation Tests

• 作 者: H.H.Nguyen[1]P.J.Wei[2]J.F.Lin[3]
• 机 构: Institute of Nanotechnology and Microsystems Engineering National Cheng Kung University, Tainan, Tai
• 出 处: 2014年海峡两岸破坏科学与材料试验学术会议暨第十二届破坏科学研讨会、第十届全国MTS材料试验学术会议
• 发表日期: 2014年期

　　Analytical model for transitions of film/substrate specimens is proposed on the basis of an elastoplastic model and the concept of virtual indenter.The indentation depth is generally expressed to be sum of films and sub strates depths, which are related to the virtual inclined angle varying with dimensionless depth, the ratio of depth to film thickness.Distinct exponential functions of virtual inclined angle well describe the loading and unloading transitions.For loading transition, virtual inclined angle is found to depend on the dimensionless depth of power 1.5; for unloading transition, the power is 1.0.The transition indices, in functions of virtual inclined angle, are related to the ratios of elastic modulus and tree hardness.