A Method to Eztract the Intrinsic Mechanical Properties of Soft Metallic Thin Films Based on Nanoindentation Continuous Stiffness Measurement Technique
In order to determine accurately the intrinsic hardness of the soft metallic thin film on a hard substrate using nanoindentation, a proper methodology irrespective of several important effects the OliverPharr method concerns is described. First, the original analysis data such as the load, P, and contact stiffness, S, as a function of the indentation depth, h, are acquired by means of the continuous stiffness measurement (CSM) technique. By CSM, the complicating effects including indentation creep behaviour of metal materials as well as thermal drift on the measured results arc avoided effectively. Then, the hardness of film-only is calculated via a material characteristic parameter, P/S2, which is independent of the contact area, A, based on the constant modulus assumption method. In this way, the influences of the substrate contribution and material pile-up behaviour neednt be accounted for. Guided by above ideas, moreover, a 504 nm Au film on the glass substrate system was chosen to study. The results show that the hardness of Au thin film is 1.6±1 GPa, which agree well with the literature. While the composite hardness measured by Oliver-Pharr method is between 2~3GPa, obviously, which is overestimated. This implies the present methodology is a more accurate and simple way for extracting the true hardness of the soft metallic thin films.
X Y Zhou Z D Jiang H R Wang Q Zhu
Institute of Precision Engineering, Xian Jiaotong University, Xian 710049, China Institute of Precision Engineering, Xian Jiaotong University, Xian 710049, China State Key Laborat
国际会议
第四届仪器科学与技术国际会议( 4th International Symposium on Instrumentation and Science and Tcchnology)
哈尔滨
英文
1096-1101
2006-08-08（万方平台首次上网日期，不代表论文的发表时间）