涂料对消失模铝合金铸件孔隙率的影响

利用HST 2型消失模涂料高温性能测试仪研究了涂料组成、涂层厚度、透气性、温度等对聚苯乙烯热解产物通过消失模涂层的传输特性的影响。结果表明 :增加云母粉、珠光粉加入量及涂层厚度 ,涂层透气性下降 ,热解产物传输曲线的峰值上升 ,传输时间增长。探讨了模样热解产物通过涂层的传输行为对消失模铝铸件孔隙率的影响。研究发现 ,热解产物传输曲线峰值高、传输时间长 ,有利于减少铝件的孔隙率。当热解产物传输曲线的峰值及传输时间分别达到 0 .4 12kPa和 4 8.3s以上时 ,铝铸件的针孔率可达到一级。实验结果表明 ,自制的HW 1涂料的传输性能可与美国Ashland涂料的相当

Effect of coating on porosity of aluminum alloy casting in lost foam process

The effects of coating constituent, coating layer thickness, permeability and temperature on transfer behaviors of decomposition products through coating layer were studied with HST 2 instrument of high temperature permeability for lost foam coating. The results show that the peak values and transfer time increase with the increase of Zhuguang powder and mica content, coating thickness and with the decrease of permeability. The relationship between casting porosity and transfer behavior of decomposition products was researched. It is pointed out that high peak value and long transfer time are helpful for decreasing the porosity of castings. When the peak value and transfer time are more than 0.412?kPa and 48.3?s, the rating of porosity of aluminum casting can reach grade 1. The results show that the transfer properties of self developed HW 1 coating are as good as those of Ashland coating in American.