基于冷金属过渡技术的Al-Cu-Mg-Zn合金焊缝凝固裂纹抑制机制

Solidification Cracking Restraining Mechanism of Al-Cu-Mg-Zn Alloy Welds Using Cold Metal Transfer Technique.

作者信息

Li Zhuoxin, Ou Lingshan, Wang Yipeng, Li Hong, Bober Mariusz, Senkara Jacek, Zhang Yu

机构信息

Institute of Light Alloy and Processing, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China.

Department of Welding Engineering, Faculty of Production Engineering, Warsaw University of Technology, 02-524 Warsaw, Poland.

出版信息

Materials (Basel). 2023 Jan 11;16(2):721. doi: 10.3390/ma16020721.

DOI:10.3390/ma16020721

PMID:36676463

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9865024/

Abstract

Aluminum alloy 7075 (with 7055 and 7150 filler wires) was welded using a digital welding machine that can switch arc mode between MIG, CMT and CMT+P modes. The transverse-motion weldability test of joints welded under different arc modes showed that the solidification cracking susceptibility was lower in CMT-technique-based welds than in MIG welds. The temperature cycle of the welding pool under different arc modes was recorded using mini-thermocouples, which showed that the cooling rate was lower in CMT welded samples than in MIG welded samples. The low cooling rate promoted the growth of α-Al dendrites through the back diffusion effect. Electron probe micro-analysis showed that micro-segregation of the α-Al dendrites was lower in the CMT welded samples than in the MIG welded samples. The curve of each weld was calculated, which showed that CMT-based welding enhanced the bridging of adjacent α-Al dendrites, reducing the tendency for solidification cracking.

摘要

采用一台可在熔化极惰性气体保护焊（MIG）、冷金属过渡焊（CMT）和CMT+P模式之间切换电弧模式的数字焊机对7075铝合金（使用7055和7150填充焊丝）进行焊接。对在不同电弧模式下焊接的接头进行横向移动焊接性试验，结果表明，基于CMT技术的焊缝的凝固裂纹敏感性低于MIG焊缝。使用微型热电偶记录了不同电弧模式下熔池的温度循环，结果表明，CMT焊接样品的冷却速率低于MIG焊接样品。低冷却速率通过反向扩散效应促进了α-Al枝晶的生长。电子探针微分析表明，CMT焊接样品中α-Al枝晶的微观偏析低于MIG焊接样品。计算了每条焊缝的曲线，结果表明基于CMT的焊接增强了相邻α-Al枝晶的搭桥作用，降低了凝固裂纹的倾向。