A Comparative Study on Mechanical Properties and Fracture Phenomena of Silicon Steel Sheet by Small Punch Test

• Main Authors: Wu, Yu-Xiang, 吳宇祥
• Other Authors: Chao, Yi-Wu
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/35588681386393545622

碩士 === 遠東科技大學 === 機械工程研究所 === 103 === This study is focused on the use of the mechanical strength from motor rotor core silicon steel. Three numbered silicon steels are used as experimental materials for experiment comparison based on the following three test procedures. The above cross experimental data comparison is integrated from micro hardness test method, traditional tensile test method, and micro-stamping (small punch test, called SPT). Next, deformation patterns of SEM which is concerning crack growth mode and organization on the observation of the OM test pieces which is concerning micro-structure morphology will be discussed. Finally, this paper will combine and integrate the above results in regard of silicon steel mechanical properties and damage phenomena. Comprehensive comparison of the overall experiment, data and image showed crystal grain size is the key to dominate the experimental results. By contrast mechanical property data to find larger grains result in different tensile test and SPT presented. Confirmed by observing the image of the grain in SPT experiments, the ball deformation curve from applied pressure on balls that come into contact with the grain area is related to the whole phenomenon of destruction. The smaller the contact area with the ball to grain more intensive, produce faster breakdown phenomenon. Conversely the larger the contact area, the later breakdown phenomenon but with better ductility.