中國有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 15 No. 6 December 2005 |
SHI Yao-wu(史耀武)3, CHANG Bao-hua(常保華)4
（1. Department of Material Engineering, Hubei Automobile Industrial Institute,
Shiyan 442002, China;
2. Department of Mechanical Engineering, University of Waterloo, Waterloo,
Ontario, N2L 3G1, Canada;
3. School of Materials Science and Engineering, Beijing Polytechnic University,
Beijing 100022, China;
4. School of Mechanical Engineering, Tsinghua University, Beijing 100084, China）
Abstract: The TiB2 dispersion-reinforced copper-matrix composite used as electrode material in resistance spot welding of zinc coated steels was studied. The service life of the composite electrode reaches 7700 welds, which is 4 times that of the conventional Cu-Cr-Zr electrode. Little gross deformation is observed on the composite electrodes because of the higher thermal strength; therefore, it is believed that wear is the only mechanism for the composite electrode deterioration. However, both wear and plastic deformation are responsible for the large increase in the tip diameter of the Cu-Cr-Zr electrodes. Moreover, the large deformation of the Cu-Cr-Zr electrodes may contribute to the increased wear rate of the tips.
Key words: Cu-TiB2 electrodes; electrode materials; resistance spot welding; TiB2 dispersion-reinforced copper-matrix composite; zinc coated steels; degradation mechanism
