单辊淬冷Cu─Pb亚偏晶合金的凝固组织特性

Microstructure of Melt-Spun Cu-Pb Hypomonotectic Alloys

应用单辊方法，研究了Ｃｕ－Ｐｂ亚偏晶合金的快凝特性，发现其中存在两类性态的组织：等轴晶与共生。对于等轴晶，Ｐｂ的偏析模式得以显著细化，对于共生，其成分范围向亚偏晶端延伸，近偏晶共生质量明显改善，并首次观察到高度规整的放射状共生。进而从传质平衡角度，建立了偏晶共生的控制方程。

Characteristics of rapidly solidified Cu-Pb hypomonotectic alloy is searched by melt spinning technique. Two kinds of microstrure, equiaxed crystals and in-situ composites are observed,of which the segregation of lead is greatly reduced in equiaxed crystals, the concentration region for composite growth is extended, the quality of near-monotectic composites is notably improved, and radiated composites are observed for the first time. From the balance of mass transfer, growth model of in-situ monotectic composites is therafter built up.