Papers by Author: Zhong Bin Tang

Abstract: The mechanical properties of various parts of the welding-line material are different, while they play very important role in the welding structures, such as the differences of the melted part and the temperature-affected part. In this paper, a non-contacting laser based technique, ISDG (Interference Strain Displacement Gauge) method, is applied to find out these property differences on very small specimen. The testing is very successful and the whole stress-strain curves in such small scale are obtained on different parts of the welding-line material. The soften phenomena of the temperature-affected part is observed by the comparison of the Young’s modulus and yield stress between the melted part and the temperature-affected part.

Abstract: A micro-scale uniaxial tension test method for measuring material mechanical properties of thin film materials is introduced in this paper. A self-developed test device is established based on the CMT8202 tension test machine. The Interference Strain/Displacement Gauge (ISDG) method is used to measure the strain in the micro-samples. The three dimensional finite element method (FEM) is utilized to optimize specimen geometry configuration and to reduce the stress concentration in specimen around grip region. The experiments are carried out for the polycrystalline copper thin film. The results show that stress-strain curves and the Young’s modulus of the thin film material can be obtained by micro-scale tension test. The Young’s modulus determined by micro-sample for polycrystalline copper thin film has a good agreement with published results.