工艺因素对干砂消失模铸铝件针孔影响的研究

Investigation on the Effects of Process Variables on Pinhole of Aluminum Alloy Castings in EPC Process

系统研究了各工艺因素对干砂消失模铸铝件密度的影响。结果表明 ,涂层厚度与聚苯乙烯模样厚度增加 ,铸铝件密度下降、针孔增加。为减少铸铝件的针孔 ,铝合金消失模铸造应有适当高的浇注温度和合适的直浇道高度及面积 ,并尽量采用空心直浇道。充型过程中施加一定的真空度有利于减少针孔 ,但真空度太高则会促使铝液产生紊流 ,反而增加铸铝件的针孔 ,降低其密度。

The effects of various process variables on the density of aluminum alloy castings have been investigated systematically.The results show that the casting density decreases with the thickness of coa ting and polystyrene pattern increasing.To decrease the casting pinholes,there should be higher pouring temperature and a suitable sprue height and area.The hollow sprue and suitable vacuum pressure is helpful to decreasing the pinhole,but,when the vacuity is too high,the liquid aluminum would become turbulence causing pinholes increased.