铝钙合金熔化和凝固过程中的气泡演变  

Bubbles Evolution of Aluminum-calcium Alloy in Melting and Solidification Process

作　　者：戴志勇[1] 张曙光[1] 张龙[1] 卢温泉[1] 李建国[1] 

机构地区：[1]上海交通大学材料科学与工程学院,上海200240

出　　处：《热加工工艺》2015年第3期87-89,共3页Hot Working Technology

基　　金：上海市科委资助项目(11JC1405900);国家自然科学基金资助项目(51027005)

摘　　要：利用上海光源(BL13W1线站)的同步辐射成像技术,观察到Al-Ca合金小球在熔化与凝固过程中气泡与气孔之间的演变过程。结果表明,在加热熔化过程中,不规则气孔随着周围枝晶网络强度的降低而逐渐球化,而冷却凝固过程中,情况正好相反,除了个别气泡保持球形外,大多数气泡被枝晶网络压挤受限成不规则形状。气泡群的初始直径呈现高斯分布的特征,它是由气泡的异质形核特性所决定的。随着气泡运动、碰撞、合并等过程的进行,气泡直径就不再维持随机分布形式。Evolution process between pores and bubbles of A1-Ca alloy balls in melting and solidification process was observed by using synchrotron radiation imaging technique of Shanghai synchrotron radiation facility （BL13Wl line station）. The results show that,in the heating and melting process, irregular pores is gradually spheroidizing with reduction of peripheral dendritic network strength. And the situation is reversed in the solidification process. Except for individual bubbles remaining spherical, most bubbles are squeezed into irregular shapes by the dendrite network. The initial diameters of the bubble group present Gaussian distribution characteristic, which is determined by the property of the heterogeneous nucleation of bubbles. With the movement, collision and merging of bubbles, the distribution of bubble diameters is no longer maintaining stochastic distribution.

关 键 词：同步辐射成像 气泡 气孔 铝合金 

分 类 号：TG243[金属学及工艺—铸造] TG244.3