初始濃度於錫鉛合金方向性凝固之影響分析

Experimental Analysis of Initial Concentration Effect on the Directional Solidification of Sn-Pb Alloys

10.29809/JTFS.200706.0006

趙隆山(Long-Sun Chao)；陳毓儒(Yu-Ru Chen)；林五祥(Wu-Shiang Lin)

鑄造 ； 方向性凝固 ； 錫鉛合金 ； 顯微結構 ； Casting ； Directional Solidification ； Sn-Pb Alloy ； Microstructure

鑄造工程學刊

33卷2期（2007 / 06 / 01）

54 - 62

繁體中文

一般的鑄造過程不易控制凝固結構之形態，其中改變晶粒大小是較容易做到，而方向性凝固是屬於難度較高之鑄造技術，需使用適當的鑄造機制，來控制其凝固結構的形態。針對方向性凝固之研究，本文設計一鑄造實驗模式，以錫鉛合金為測試材料，採用五種不同初始濃度(Sn-2.5，5，10，20，38wt.%Pb)，使用光學顯微鏡觀察凝固顯微結構，並計算鑄件橫截面的晶粒數目，且利用熱偶線與溫測擷取系統，量測鑄件軸向之溫度分布。由這些實驗結果，來探討本研究中方向性凝固之控制參數（初始濃度）與凝固顯微結構之間的相關性，同時從此分析結果，可進一步了解與掌握方向性凝固之控制機制。

The morphology of solidification microstructure is difficult to control in a casting process, in which only the grain size can be easily changed. To perform advanced casting techniques such as directional solidification and the growth of single crystal, a proper casting mechanism is needed to control solidifying microstructure. Among these solidification processes, the growth of single crystal is the most difficult one and directional solidification is the second. The fabricating technique of single crystal is based on that of directional solidification. To obtain directional solidification, in this paper, the experiment models are designed to investigate. In this study, Pb-Sn alloy is used as the testing material and five different initial concentrations of lead (Sn-2.5, 5, 10, 20, 38wt.% Pb) are used in Model. An optical microscope is utilized to observe the solidifying microstructure and the thermal couples are used to measure the temperatures along the axial direction of the cylindrical casting. The relationship between solidification parameters (initial concentration) and microstructures were investigated for models. From the analysis results, the controlled mechanism of directional solidification can be further grasped.