熔体状态与冷速对Pb-Sb90合金初生相生长形貌的综合作用  

Combined Effects of Melt Status and Cooling Rate on Crystal Morphology of Primary Phase of Pb-Sb90 Alloy

作　　者：丰大顺[1] 张文进[1] 张先锋[1] 高文龙[1] 祖方遒[1] 

机构地区：[1]合肥工业大学材料科学与工程学院金属液固加工研究所,安徽合肥230009

出　　处：《铸造工程》2013年第2期1-4,共4页Foundry Engineering

基　　金：高等学校博士学科点专项科研基金《合金熔体状态对高熔融熵物质结晶学各向异性的作用》（2011011111014,申请人：祖方道）;国家重点基础研究发展计划资助项目（973课题）（2012CB825702）

摘　　要：首先探索了Pb-9O％Sb合金熔体升、降温过程电阻率一温度行为，其结果提示升温过程在861-1100℃区间发生不可逆熔体结构转变；进而探讨了不同凝固条件下熔体状态与冷速对其初生相（Sb固溶体）结晶形貌的综合作用。结果表明：凝固过程冷速较慢时，转变前、后两种不同状态熔体凝固后，初生相形貌均为小平面生长特征的棱角分明多面体。随着冷却速度的提高，初生相的棱角被钝化，且树枝晶比例逐渐增多；另一方面，结构转变后的熔体状态增强了初生相形貌发生改变的这一效果。当冷速增至一定程度，转变后结构状态的熔体凝固初生相形貌完全转化为非小平面生长特征，棱角分明的多面体已不复存在。This paper explores the resistivity-temperature behavior of Pb-90wt%Sb during heating and cooling processes firstly, the result shows that an irreversible melt structure transition occurs at 861- 1100 ℃. The combined effects of melt status and cooling rate on crystal morphology of primary phase （solidus solution of Sb） with different solidification conditions are investigated. The result indicates that： the morphology of primary phase is angular polyhedron with faceted feature at lower cooling rate. With higher cooling rate, the angles of primary phase are passivated, and the proportion of dendrite increases; On the other hand, melt status after structure transition strengthens this effect of morphology changes on primary phase. When the cooling rate increased to a certain extent, the morphology of primary phase of solidification structure which the melt underwent irreversible structure transition completely changes to non-faceted grow feature, and the angular polyhedron no longer exists.

关 键 词：熔体状态 冷却速度 晶体形貌 Pb-Sb合金 

分 类 号：TG146.12[一般工业技术—材料科学与工程]