Modification mechanism of eutectic silicon in Al-6Si-0.3Mg alloy with scandium

บทความในวารสาร

ผู้เขียน/บรรณาธิการ

กลุ่มสาขาการวิจัยเชิงกลยุทธ์

ไม่พบข้อมูลที่เกี่ยวข้อง

รายละเอียดสำหรับงานพิมพ์

รายชื่อผู้แต่ง: Patakham U., Kajornchaiyakul J., Limmaneevichitr C.

ผู้เผยแพร่: Elsevier

ปีที่เผยแพร่ (ค.ศ.): 2013

วารสาร: Journal of Alloys and Compounds (0925-8388)

Volume number: 575

หน้าแรก: 273

หน้าสุดท้าย: 284

จำนวนหน้า: 12

นอก: 0925-8388

eISSN: 1873-4669

URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879248373&doi=10.1016%2fj.jallcom.2013.05.139&partnerID=40&md5=4a70e199b745b51d1f3a058d78ecec64

ภาษา: English-Great Britain (EN-GB)

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บทคัดย่อ

The modification mechanism of eutectic silicon in Al-6Si-0.3Mg alloy with scandium was studied. The crystallographic orientation relationships between primary dendrites and the eutectic phase of unmodified and modified Al-6Si-0.3 Mg alloys were determined using electron backscatter diffraction (EBSD). The orientation of aluminum modified with scandium in the eutectic phase was different from that of the neighboring primary dendrites. This result implies that eutectic aluminum grows epitaxially from the surrounding primary aluminum dendrites in the unmodified alloy and that eutectic aluminum grows competitively from the surrounding primary aluminum dendrites in the modified alloy. The pole figure maps of eutectic Si in the [100], [110] and [111] axes of the unmodified and Sc-modified alloys were different, suggesting that the eutectic Al and Si crystals in modified alloy growth are more isotropic and cover a larger set of directions. The lattice fringes of Si of the alloys with and without Sc modification were different in the TEM results. The lattice fringes of Si in modified alloy were found to be multiple twins. However, this was not observed in the unmodified alloy. The growth characteristic of eutectic Si crystal in modified alloy suggests the occurrence of multiple twinning reactions and the formation of a high density of twins. This modification mechanism by Sc is explained by the results of scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analysis, which provide strong evidence of the occurrence of the impurity-induced twinning (IIT) mechanism. ฉ 2013 Elsevier B.V. All rights reserved.

คำสำคัญ

Hypoeutectic Al-Si-Mg alloy, Modification mechanism, Scandium