挤压态AZ61镁合金真空扩散焊接试验研究

Experimental Research on Vacuum Diffusion Bonding of As-extruded AZ61 Magnesium Alloy

采用再结晶退火的方式,细化挤压态AZ61镁合金晶粒,并将细化后的镁合金进行真空扩散焊接研究。剪切强度试验结果表明,在连接压力为10MPa和真空度为18Pa的条件下,扩散温度为470℃、保温时间为90min时可得到最大剪切强度51.95MPa。试验分析表明,扩散温度和保温时间是扩散焊接接头性能的主要影响因素。对扩散焊接头及其周围区域进行显微硬度测量发现,焊缝处的显微硬度最大,偏离焊缝沿母材方向的显微硬度逐渐减小。

In this investigation, a study on vacuum diffusion bonding of as-extruded AZ61 magnesium alloy was carried out according to atomic diffusion theory. The grain size of as-extruded AZ61 magnesium alloys had been refined by recrys- tallization anneal. With the refined AZ61 magnesium alloys, the vacuum diffusion bonding was studied. The results showed that in a particular situation that bonding pressure and vacuum degree were fixed as 10 MPa and 18 Pa respectively, the maximum shearing strength was 51.95 MPa with the temperature of 470 ＊C and the holding time of 90 min. It showed that the diffusion temperature and holding time have a great effect on the quality of the bonding joints. The micro hardness meas- urement data of diffusion welding joint and base metal showed that the maximum micro hardness was at the welding joint, and the farther from weld joint, the lower the micro hardness value.