Kong et al. [22] analysed the micro

Kong等。[22]分析了<br>气雾化的Al12Sn1Cu（wt。％）合金粉末的微观结构。他们报告说<br>，合金粉末颗粒的凝固行为主要取决于粉末颗粒<br>的直径，并<br>根据冷却<br>速率证明了两种可能的凝固组织。在某些气体雾化条件下，小于〜8 mm的粉末<br>颗粒在a-Al合金基体中表现出精细分散的b-Sn相颗粒。然而，较大的粉末颗粒<br>显示出具有枝晶间b-Sn相的α-Al的孔/枝晶形态的微观结构。气体<br>雾化粉末颗粒的冷却速度与其直径成反比<br>并且观察到，<br>在直径约10mm的粉末颗粒中b-Sn颗粒的尺寸为约500nm ，而在直径约1mm的粉末颗粒中减小至<br>50e200nm。<br>在AleSneCu三元体系中，对于可<br>混溶间隙稳定的组合物，<br>制造过程中的主要挑战之一是跨越较大的液相线-固相线温度范围。此特性可能导致<br>b-Sn颗粒的分布不均匀。液体不溶混性导致严重的<br>偏析，这主要是由于<br>富铝和富锡液体之间的密度差很大。据报道，单晶<br>反应对重力水平和结晶前的过冷条件非常敏感，[23,24]。即使在<br>微重力条件下，由于

孔等人[22] 分析了气体雾化的微观结构<br>Al12Sn1Cu （wt.%） 合金粉末。他们报告说，固体<br>合金粉末颗粒的阳离子行为严重取决于<br>在粉末颗粒的直径，并证明两个<br>根据冷却情况可能凝固的微观结构<br>率。在使用的某些气体雾化条件下，小于±8 mm的粉末颗粒呈现出细散的b-Sn相<br>铝合金基质中的颗粒。然而，较大的粉末颗粒<br>显示了al的细胞/树突形态的微观结构，具有间向b-Sn相。气体的冷却速率<br>雾化粉末颗粒与它们的直径成反比<br>观察到b-Sn粒子的大小是+500 nm<br>在直径为±10 mm的粉末颗粒中，同时减至<br>50e200 nm 的粉末颗粒为 ±1 mm 尺寸。<br>在阿莱斯内库三元系统中，对于<br>错位性差距是稳定的，这是<br>制造工艺是跨越大型液液-固体温度范围。这种特性会导致不均匀<br>b-Sn 粒子的分布。液体无误导致严重<br>隔离主要由于<br>富含和Sn丰富的液体。据报道，单<br>反应对结晶前的重力和冷却条件非常敏感[23，24]。即使在下<br>微重力条件，粗相分离发生由于

Kong et al. [22] analysed the microstructure of gas-atomisedAl12Sn1Cu (wt.%) alloy powders. They reported that the solidifi-cation behaviour of that alloy powder particles critically dependson the diameter of the powder particle and demonstrated twopossible solidification microstructures depending on the coolingrate. Under certain gas atomization conditions used, powder particles smaller than ~8 mm, exhibited a finely dispersed b-Sn phaseparticles in the a-Al alloy matrix. However, larger powder particlesshowed microstructures of cellular/dendrite morphology of the aAl with interdendritic b-Sn phase. The cooling rate of the gasatomised powder particles is inversely related to their diameterand it was observed that the size of the b-Sn particles was ~500 nmin powder particles of ~10 mm in diameter while decreasing to50e200 nm in powder particles of ~1 mm size.In the AleSneCu ternary system, for compositions where themiscibility gap is stabilized, one of the main challenges in themanufacturing process is to cross the large liquidus-solidus temperature range. This characteristic can lead to an inhomogeneousdistribution of b-Sn particles. The liquid immiscibility causes severesegregation mainly due to the large density difference between theAl-rich and Sn-rich liquids. It was reported that the monotecticreaction is very sensitive to the level of gravity and the undercooling condition prior to crystallization, [23,24]. Even undermicrogravity conditions, a coarse phase separation occurs due to<br>