压力下铝合金凝固过程传热的研究  

Study on Heat Transfer Behavior of Aluminum Alloys Solidification Under Pressure

作　　者：王德[1] 周成[1] 徐国进[1] 阿怀渊 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《铸造》2013年第12期1165-1171,1175,共8页Foundry

摘　　要：针对上方侧注式双辊铸轧的特点设计并制造了一个模拟装置,用来研究该工艺过程中熔体与辊面之间的传热问题。试验中分别采用1050Al和6063铝合金,以及0.8μm和3.2μm两种不同表面粗糙度的冷却基板,讨论了熔体从自由凝固到受压变形过程中,浇注温度、表面粗糙度、不同材料等对表面传热的影响,并利用数值模拟反求界面换热系数随时间变化曲线。结果表明,上方侧注式双辊铸轧过程界面传热分成3个阶段,即激冷阶段、凝固阶段和受压变形阶段。对于同种材料,过热度越大,表面传热越好;第1阶段粗糙度小的表面传热较好,在受压变形以后,较粗糙的表面传热更好;表面张力小的材料传热效果好。A set of equipment was designed and manufactured according to the characteristics of the top side-pouting twin-roll casting process. It was utilized to investigate the interracial heat transfer between the melt and roll surface during the process. Two types of aluminum alloys-1050Al and 6063 alloy, and two pieces of substrate with surface roughness 0.8 μm and 3.2 μm, were used. The effects of pouring temperature, surface roughness and materials on interracial heat transfer during the period from free solidification-to forced deforming were investigated, and the curve of interfacial heat transfer coefficient as a function of time was inversely solved by numerical simulation. The results show that the interracial heat transfer behavior of the top side-pouring twin roll casting process consists of 3 stages, namely, the chilling stage, the solidifying stage and the forced deforming stage. Materials with lower surface tension have the larger heat transfer coefficient, and as the same material, the heat transfer coefficient in the chilling stage is bigger on a smooth surface, whereas in the forced deforming stage, a larger heat transfer coefficient is obtained on the rougher surface.

关 键 词：界面换热系数 上方侧注式 双辊铸轧 数值模拟 

分 类 号：TG146.21[一般工业技术—材料科学与工程]