Droplets of Ag60Sb34Cu6 ternary alloy within the diameter range of 60—800 μm were rapidly solidified by means of drop tube containerless processing, and the solidi- fication mechanism is analyzed. With a decrease in...Droplets of Ag60Sb34Cu6 ternary alloy within the diameter range of 60—800 μm were rapidly solidified by means of drop tube containerless processing, and the solidi- fication mechanism is analyzed. With a decrease in droplet size, the cooling rate increases from 57 to 5.8×104 K/s. The maximum undercooling is determined to be 180 K (0.23TL) and the microstructure of primary ε(Ag3Sb) dendrite refines drastically until homogenous equiaxed dendrite forms. Ex- perimental results indicate that (ε+Ag) pseudobinary eutectic cannot form under high undercooling conditions and the solubility of Ag in primary ε phase increases as undercooling increases. Based on thermal analysis and crystal growth morphology, it is found that this alloy is solidified in two ways corresponding to different undercooling levels.展开更多
文摘Droplets of Ag60Sb34Cu6 ternary alloy within the diameter range of 60—800 μm were rapidly solidified by means of drop tube containerless processing, and the solidi- fication mechanism is analyzed. With a decrease in droplet size, the cooling rate increases from 57 to 5.8×104 K/s. The maximum undercooling is determined to be 180 K (0.23TL) and the microstructure of primary ε(Ag3Sb) dendrite refines drastically until homogenous equiaxed dendrite forms. Ex- perimental results indicate that (ε+Ag) pseudobinary eutectic cannot form under high undercooling conditions and the solubility of Ag in primary ε phase increases as undercooling increases. Based on thermal analysis and crystal growth morphology, it is found that this alloy is solidified in two ways corresponding to different undercooling levels.
