Effect of electrode wear on weld nugget formation in resistance spot welding of magnesium alloy

来源期刊：中国有色金属学报(英文版)2005年第z3期

论文作者：王亚荣 冯吉才 张忠典

文章页码：327 - 330

Key words：Mg alloy resistance spot welding； electrode wear； FEM simulation

Abstract: The effect of electrode wear on the formation and growth of weld nugget in resistance spot welding of AZ31B Mg alloy was studied by an axisymmetric finite element model, employing a contact resistance model based on the micro-contact theory. The results show that electrode wear causes the growth of electrode tip diameter, which leads to the current density and temperature at the sheet/sheet interface reduced and diameter of nugget decreased, has been shown to be dominant in determining the deterioration in weld quality. Alloying and pitting at electrode surface decrease the electric conduction of electrode, resulting in non-uniform distribution of temperature and current density and contribution to the further damage, at the same time initiate expulsion and electrode sticking during welding process and worse the quality of weld.