铝合金石膏型精铸呛火预防措施

Boiling and Preventive Measures of Gypsum Mould Precision Casting of Al Alloy

通过对铝合金石膏型精铸过程呛火问题进行分析。结果表明,由于在焙烧期间降温吸潮,石膏型在浇注过程中很容易发生呛火,致使铸件产生严重皮下气孔、氧化夹杂等缺陷。通过对焙烧炉外部结构进行改进,确保降温阶段炉膛与外界隔离以防止外部湿气进入,从而使石膏型浇注时呛火次数明显减少。

Boiling problem of AI alloy precision casting with gypsum mould was analyzed. The results show that with the gypsum mould that absorbed the moisture during the cooling of the roasting process, boiling easily happened, which resulted in severe casting defects such as the subsurface pin-holes, the oxides and inclusions after solidification. By improving the external structure of the roasting furnace to ensure isolation of furnace from outside moisture air, the numbers of boiling during the pouring process were obviously decreased with gypsum mould.