压铸工艺参数对铝合金汽缸体孔隙率的影响

Influences of Die Casting Parameters on the Porosity in Aluminum Alloy Air-conditioning Compressor Cylinder

通过测量铸件热处理前后密度变化率,系统研究了压铸过程中浇注温度、铸造压力、快压射速度、快压射切换位置等工艺参数对铝合金汽车空调压缩机汽缸体孔隙率的影响规律。结果表明,铸件内的孔隙率随着浇注温度的升高和快压射速度的增加而增大,随着快压射切换位置的增加而减小,随着铸造压力的增加先增大后变小。综合考虑,浇注温度为700～720℃,铸造压力为104MPa,压射速度为1.5m/s,快压射位置为320mm时,铸件孔隙率最小,性能最好。

Effects of processing parameters including pouring temperature, casting pressure, fast shot speed and fast shot shift point on porosity in aluminum alloy air-conditioning compressor cylinder were investigated by measuring density of as-cast and heat treated die casting cylinder. The results reveal that porosity rate in the cylinder is increased with increasing in pouring temperature and in fast shot speed while it is decreased with increasing in fast shot shift point, and it is firstly increased then decreased with rising in casting pressure. Minimum porosity in the cylinder can be obtained with pouring at 700~720℃ and casting pressure of 104MPa, shot velocity of 1.49m/s as well as fast shot shift distance at 320 mm, exhibiting desirable properties.