铝合金压铸件浇口夹渣的分析及改善

Analysis and Improvement of Slag Gate in Aluminum Alloy Die Castings

摩托车发动机铝合金曲轴箱体在压铸毛坯时常会出现浇口夹渣现象,而浇口夹渣又多为类似缩孔、油污和冷硬层3种形式。引起夹渣的原因主要是模具温度过高、冲头油过量和Al液含渣量高等。解决缩孔类夹渣,主要从降低模具温度入手;油污类夹渣,可采取调整冲头润滑油用量、加注位置及供给方式;应对冷硬层夹渣,主要靠调整压射延时和调整汤勺退回待机时间、过滤汤勺式样的导入、规范Al液除渣除气作业要求等措施。

The motorcycle engine crankcase is common produced by die casting aluminum alloy,and gate slag easily occurs in the die casting aluminum alloy crankcase.The gate slag is classed into three kinds of types：shrinkage cavity,oil,chilled layer.The main reasons are attributed to a higher mold temperature,excessive lubricant and high impurities in molten aluminum alloy.Through decreasing mold temperature,shrinkage cavity can be eliminated effectively.Aiming at oil slag,some measures,such as adjusting punch lubricant volume,adding location and supplying ways,were taken into account.For eliminating chilled layer slag,some ways are effective including modifying shoting time,staying time and strictly controlling degassing in the liquid aluminum alloy.