提出具有节能高效特征的粉末铝热剂介入型电阻点焊新技术,通过添加ZnO+Al粉末铝热剂介入2024铝合金电阻点焊,研究了铝热剂介入对电阻点焊熔核成形、显微组织、力学性能等质量因素的影响。结果表明,在ZnO+Al粉末铝热剂冶金反应热的辅助作用下,可以有效增大2024铝合金的电阻点焊溶核尺寸以及熔核内部树枝晶区尺寸。粉末铝热剂的添加,使熔核中心区域拥有更多的异质形核晶核,促使凝固进程中的固-液界面前沿出现大范围成分过冷,更有利于等轴晶的形核,使等轴晶的分布更为均匀,细化熔核中心等轴树枝晶束。同时,也强化熔核胞状晶区,使熔核强韧性得到提高。最终在试验焊接电流范围内提高焊点强度28%~200%。 A new energy-saving and energy-efficient intervened resistance spot welding technology was proposed. By adding ZnO + Al powder thermite to 2024 aluminum resistance spot welding, the influence of thermite on the resistance nugget formation was studied. Micro-organization, mechanical properties and other quality factors. The results show that the resistance nucleation size and dendritic size of 2024 aluminum alloy can be effectively increased with the aid of the metallurgical reaction heat of ZnO + Al powder thermite. The addition of powder thermite has more heterogeneous nucleation nuclei in the central region of the nugget, which promotes the overcooling of a wide range of components at the front of the solid-liquid interface in the solidification process and is more conducive to the nucleation of equiaxed crystals. So that the distribution of equiaxed grains more uniform thinning equiaxed dendrite beam nugget center. At the same time, also strengthen the nugget cell crystal zone, nugget toughness is improved. Finally, in the test welding current range to improve the solder joint strength of 28% to 200%.