文章信息/Info

Title:

Investigation of the non-equilibrium solidification and microstructures of Al-Y Peritectic Alloys

作者:

王亮; 張延寧; 駱良順; 劉冬梅; 蘇彥慶*; 郭景杰; 傅恒志

 

 哈爾濱工業大學材料科學與工程學院，金屬精密熱加工國家級重點實驗室

Author(s):

 WANG Liang;  ZHANG Yanning;  LUO Liangshun;  Liu Dongmei;  SU Yanqing*;  GUO Jingjie;  FU Hengzhi

 National Key Laboratory for Precision Hot Processing of Metals, School of Materials Science and Engineering, Harbin Institute of Technology

關鍵詞:

Al-Y包晶合金; 金屬間化合物; 非平衡凝固; 差熱分析

DOI:

10.7502/j.issn.1674-3962.2014.06.04

文獻標志碼:

A

摘要:

包晶凝固過程中小平面-小平面兩相復相生長方式是凝固領域研究的一個熱點。本文以初生相和包晶相都是嚴格計量比金屬間化合物的Al-Y包晶合金作為研究對象，利用DSC熱分析技術，嚴格控制冷卻速度，獲得不同凝固條件的非平衡凝固試樣，研究了兩相為小平面相的Al-Y包晶合金的凝固行為。發現小平面-小平面包晶系合金包晶凝固過程中，非平衡凝固特性及宏觀偏析特點比非小平面包晶系更加明顯。凝固特征溫度與平衡相圖偏差明顯，包晶反應溫度和包晶相直接凝固溫度都遠高于平衡相圖給定的值，最后得到的凝固組織也與平衡相圖存在顯著差異。

Abstract:

Facted-facted two-phase peritectic solidification behaviors are one of the hotspot of solidification field. In this study, Al-Y peritectic alloys, in which the peritetic phase and primary phase are intermetallic compound with stoichiometric composition, have been chosen for investigation. Using differential scanning calorimetry (DSC), obtained the heating and cooling curves of Al-Y alloys at different strictly controlled cooling rates. Concurrently, the non-equilibrium solidification microstructures were produced. Based on these experimental results, we found that the non-equilibrium solidification characteristics and characteristics of macrosegregation of the facted-facted peritectic alloy solidification process are more obvious than non-faceted peritectic alloys. The solidification characteristic temperature is greatly different to the equilibrium phase diagram. The peritectic reaction temperature and the nucleation temperature of peritectic phase from the melt during cooling are higher than that of the equilibrium phase diagram. The resulting solidification microstructures are also significant differences with the equilibrium phase diagram.