摘要
对铝合金石膏型真空浇注加压凝固精铸件上表面缺陷无法补焊问题进行分析,发现由于铝合金在精炼过程中存在吸氢过量,导致在凝固时向Al2O3双膜迁移。当对铸件上表面缺陷进行补焊时,补焊区周围的氢随着温度的升高向Al2O3双膜处偏聚,双模内压力增大,最终导致双膜破裂而无法焊合。通过除氢以及密度检验,可以将铝液中的氢含量控制在一定范围,就可避免无法焊合的问题。
Welding-repair failure of aluminum alloy parts produced with gypsum mould by investment casting combining with vacuum pouring and solidification under pressure were analyzed. The results show that excessive hydrogen absorbed in the refining process can migrate towards the oxides and AI2 03 double membrane in the process of solidification. During welding repair at defect surface of the upper castings, hydrogen concentration around the repair welding areas partially plays toward the A12 03 doub- le membrane with the temperature increases, leading to the double membrane rupture to failure of weld- ing repair as a result of pressure increase. By the degassing treatment and density measurement method, the hydrogen content in the A1 alloy melt was controlled in a certain range, and failure of welding-repair could be improved.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2014年第7期740-742,共3页
Special Casting & Nonferrous Alloys
关键词
石膏型
补焊
真空浇注
加压凝固
Gypsum Mold, Welding Repair, Vacuum Pouring, Pressurized Solidification
