【摘要】 利用电触点法研究了工艺参数对消失模铸造AZ91合金的流动形态和流动速度的影响.结果表明,AZ91合金熔液以凸弧形平稳地向前逐层置换泡沫,这是由于裂解产物在流动前沿尤其模样边缘处的大量堆积造成的.充型时间随浇注温度、真空度的提高而变短.充型过程中充型速度呈现交替变化.以熔融金属作为振子,熔体和泡沫模之间的气层作为弹簧建立弹簧-振子模型,可以诠释充型速度的交替变化.更多还原

【Abstract】 This paper deals with the effect of a number of processing parameters on the melt front profile and fluid velocity using electrical probes embedded in the foam pattern in the Lost Foam Casting(LFC) of AZ91 magnesium alloy.The experimental results showed a convex profile was typically observed during the whole mold filling stage in the most cases-this was caused by a large buildup of polymer residue,particularly at the top surface of the casting.The mold filling time decreased with pouring temperature or vacuum degree increasing.Furthermore,the alternate variation of the velocity was found during the mold filling and the phenomena can be explained by a mass-spring model,where the melt behaves as mass and the gas layer between the melt and foamed pattern behaves as spring.更多还原