【摘要】 通过数值模拟计算,发现低压铸造铝合金轮毂在充型完成后的很短时间内,铸件各部分都开始凝固,差别在于每一时刻各部位固相率不同。铸件缩松产生的原因是补缩通道的凝固冷却曲线与被补缩部分的凝固冷却曲线存在部分重合。在不改变模具结构的情况下,在上下模具轮辐对应部位覆盖隔热层,可使得轮辐部位的凝固冷却曲线位置升高,实现轮辐处冷却曲线与轮辋与轮辐的连接处的冷却曲线分离,消除轮辋与轮辐连接处的缩松缺陷;覆盖隔热层后,被覆盖的模具部分温度升高了20℃左右。更多还原

【Abstract】 It was found that the entire cast solidification started in a short time after being filled based on the numerical simulation under the conditions of low pressure casting.The difference of the solidification in solidification came from the solid content in different position varied with the cooling condition.The formation of the shrinkage was attributed to cooling curve in the feeding zone partly coincidences with that in needed feeding zone.The insulation layer was designed to set on the positions corresponding to the wheel rib in the upper core and bottom core,which made position of the cooling curve at the spoke increase,realizing cooling curves separation between the spoke and conjunction location of the rib and elimination of the shrinkage porosity(holes) at the conjunction.The temperature in the area of mold being covered by the insulation boards was raised by approximately 20 ℃.更多还原