摘要
建立了搅拌摩擦焊接过程中焊缝表面弧形纹形成过程模型,解释了弧形纹弧峰、弧谷的形成原因。焊接过程中,轴肩与母材表面间所形成的软化层沿着搅拌头的转动方向缓缓向轴肩后方流动,形成了软化薄层,并不断增厚。当轴肩与流动到轴肩后侧的软化层两者界面处的分子间吸附力不足以带动软化层整体向前运动时,软化层外侧的薄层与轴肩脱离,并在随后的冷却过程中硬化而形成弧峰。上述行为在搅拌摩擦焊接过程中反复发生,导致相邻弧峰间产生一凹陷,形成孤谷。焊缝表面相邻弧峰间距与搅拌头行走速度成正比,与搅拌头的转速、轴肩/母材间的摩擦系数成反比。
This paper established a process model of arc corrugation on friction-stir weld, which explained the forming reason of arc crest and trough. The softened layer on the interface between shoulder and parent material flow slowly to the back of shoulder in the direction of tool rotation during welding, resulting in softened material accumulating behind shoulder. When the accumulated layer was so thick that the folium outside the layer lagged and formed arc corrugation during cooling, resulting from the intermolecular attraction between shoulder and softened material being insufficient to drag all softened material. The above process occurred constantly, resulting in arc trough between two adjacent arc crest. The space between two adjacent arc crest depended on tool rotational speed, travel speed and shoulder/parent material interfacial friction coefficient.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2003年第5期42-44,共3页
Transactions of The China Welding Institution
基金
国家863基金(2002AA724040)
