消失模铝铸件针孔形成机理研究

Investigation on the Mechanism of the Pinhole Formation of Aluminum Alloy LFC Process

探讨了铝液变质、晶粒细化、浇注温度及聚苯乙烯模样等对消失模铝铸件针孔的影响 .研究结果表明 ,干砂消失模铸造工艺冷却速度比树脂砂工艺和粘土砂工艺慢 ,更易产生针孔 ;若用0 .2 %Ti对消失模铸造铝液进行细化处理 ,则可以大大减少冷却速度慢对其针孔形成的不利影响 ,使铝件密度接近或达到树脂砂工艺的水平 .为减少针孔 ,应尽量采用低密度的聚苯乙烯模样 。

The effects of modification, grain refinement, polystyrene pattern, pouring temperature on aluminum alloy porosity in LEC process is studied. The results show that the solidification rate in LFC process is slower than that of in resin sand process or clay sand process. Through refinement process with 0.2%Ti for aluminum melt, the subversive effect of slow solidification rate on aluminum casting porosity formation in LFC process is decreased greatly, and the aluminum casting density in LFC process is nearly equal to that in resin sand process. To decrease the porosity for aluminum castings in LFC process, lower density of polystyrene pattern, higher pouring temperature(760～780℃)should be applied.