冷却速率对高强度铝合金铸件机械性质与微孔隙关系之研究

Influence of Cooling Rate on the Mechanical Properties and Porosity Content of High Strength Aluminum Alloy Castings

以100%硅砂(A类模)、50%硅砂和50%铬砂(B类模)及100%铬砂(C类模)制作砂模,并有系统改变A201铝合金平板铸件的长度、厚度及冒口大小的方案设计,探讨不同冷却速率对A201平板铸件抗拉强度及微孔隙的影响情形,进而于铸造实务工作时,可为冒口设计及金属凝固之参考,为本研究的目的。由实验结果显示,A201铝合金平板铸件的机械性质及微孔隙受冷却速率的影响,铸件的抗拉强度随微孔隙的量增加而降低。铬砂制作的砂模可让铸件有较快的冷却速率,但也产生较多的微孔隙。

The influence of cooling rate on the mechanical properties and the amount of porosity was studied by adopting 100% silica sand（type A mold）, 50% silica sand and 50% chromite sand （type B mold）, and 100% chromite sand （type C mold） and changing the length and thickness of A201 aluminum alloy plate and the riser size systematically. The result shows that cooling rate affects the the amount of porosity and mechanical properties of the castings. The tensile strength decreased with the amount of porosity. The cooling rate is faster in chromite sand mold, but also causes more porosity in castings.