Effect of B addition on the formation of Fe-rich phases in Al-Si-Fe alloys

被引：30

作者：

Song, Dongfu ^{[1
,2
]}

Zhao, Yuliang ^{[3
,6
]}

Jia, Yiwang ^{[1
]}

Huang, Guangyao ^{[1
]}

Zhang, Zhibo ^{[1
]}

Zhou, Nan ^{[1
]}

Li, Xintao ^{[1
,4
]}

Zheng, Kaihong ^{[1
]}

Fu, Yanan ^{[5
]}

Zhang, Weiwen ^{[2
]}

机构：

[1] Guangdong Acad Sci, Guangdong Prov Key Lab Met Toughening Technol & Ap, Inst New Mat, Guangzhou 510650, Peoples R China

[2] South China Univ Technol, Natl Engn Res Ctr Near Net shape Forming Met Mat, Guangzhou 510641, Peoples R China

[3] Dongguan Univ Technol, Neutron Scattering Tech Engn Res Ctr, Sch Mech Engn, Dongguan 523808, Peoples R China

[4] Jiangxi Universal New Mat Technol Co Ltd, Shangrao 334499, Peoples R China

[5] Chinese Acad Sci, Shanghai Adv Res Inst, Shanghai Synchrotron Radiat Facil, Shanghai 201204, Peoples R China

[6] Dongguan Univ Technol, Dongguan 523808, Peoples R China

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2023年 / 930卷

基金：

中国国家自然科学基金;

关键词：

Fe -rich phase; B addition; Al -Si alloy; Solidification; Synchrotron X-ray radiography; First -principles calculations; GRAIN REFINING MECHANISM; ALPHA-AL2O3; 0001; SURFACE; ALUMINUM FOUNDRY ALLOYS; X-RAY RADIOGRAPHY; CRACK INITIATION; CAST-ALUMINUM; REFINEMENT; NUCLEATION; BORON; INTERMETALLICS;

D O I：

10.1016/j.jallcom.2022.167426

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Boron (B) is an effective grain refiner in Al-Si alloys, but the mechanism responsible for the effect of B on the formation and growth of Fe-rich phases is still in debate. In this paper, we used in-situ synchrotron X-ray radiography, combined with optical microscopy, scanning electron microscopy, thermodynamics and first -principles calculations, to study the influence of B on the nucleation and growth of Fe-rich phases in Al-7Si-xFe (x = 1.2-3.0) alloys. The results showed that B had an excellent influence on the grain refinement of Al-7Si-1.2Fe alloys, but it had no obvious effect on the morphology and distribution of Fe-rich phases due to the eutectic reaction to form Al-AlB2. B had a certain refining effect on primary Fe-rich phases in Al-Si-Fe alloys with high Fe content (>= 2.36 wt. %), but it cannot completely inhibit the formation of these plate-like Fe-rich phases. The in-situ synchrotron X-ray radiography results showed that the addition of B significantly reduced the formation temperature of primary Fe-rich phases. First-principles calculations showed that the adsorption energy of B on the nucleation sites , e.g., <<-Al2O3 (0001), was significantly higher than that of Fe, which inhibited the nucleation of the primary Fe-rich phase above the Al-AlB2 eutectic temperature and promoted its undercooling of nucleation. Furthermore, many <<-Al nuclei formed during the transition to the Al-AlB2 eutectic; their subsequent growth hindered the development of the primary Fe-rich phase. The results of this study provide insights for designing new recycled Al-Si alloys and fundamental knowledge of Fe-rich phase modification by B addition. (c) 2022 Elsevier B.V. All rights reserved.

引用

页数：11