國立虎尾科技大學 |

Mechanism of Grain Refinement of Aluminum By Al-5Ti-1B Master Alloy.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Mechanism of Grain Refinement of Aluminum By Al-5Ti-1B Master Alloy./
Author:	Liu, Xingtao.
Description:	1 online resource (67 pages)
Notes:	Source: Masters Abstracts International, Volume: 56-06.
Subject:	Materials science. -
Online resource:	click for full text (PQDT)
ISBN:	9780355156706

Mechanism of Grain Refinement of Aluminum By Al-5Ti-1B Master Alloy.
Liu, Xingtao.

Mechanism of Grain Refinement of Aluminum By Al-5Ti-1B Master Alloy. - 1 online resource (67 pages)

Source: Masters Abstracts International, Volume: 56-06.

Thesis (M.S.)--Purdue University, 2017.

Includes bibliographical references

Grain refinement is a vital technique in aluminum (Al) casting industry, in which Al-5Ti-1B (5 wt. pct Ti and 1 wt. pct B) master alloy is often used as a grain refiner. Castablity and processability of aluminum can be enhanced substantially. Different theories of grain refinement were proposed in the past few decades, however, there is still no consensus on the mechanism of Al grain refinement. In this study, Al-5Ti-1B master alloy was diluted at different ratios. Scanning electron microscopes (SEM) are used for microstructure characterization. Based on microstructural analysis, it is speculated that a dynamic Ti-rich layer is formed on the surface of TiB2 particles to nucleate aluminum (alpha-Al) grains. But the Ti-rich layer will subsequently be dissolved through a peritectic reaction and release Ti atoms in to the aluminum matrix. A small amount of dissolution of TiB2 releases Ti atoms making a Al3Ti layer of a few atoms thick remain, contributing to the nucleation of alpha-Al grains. The rates of Al3Ti layer and TiB2 dissolution are different, so the appearance of Al 3Ti layer will be sporadic, forming a dynamic layer. Therefore, the nucleation and growth of Al3Ti phase is a dynamic process. Based on microstructure analysis, a dynamic nucleation theory is proposed in this investigation.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9780355156706Subjects--Topical Terms:

557839
Materials science.
Index Terms--Genre/Form:

554714
Electronic books.

Mechanism of Grain Refinement of Aluminum By Al-5Ti-1B Master Alloy.
LDR:02435ntm a2200325K 4500 001 914122
005 20180703084422.5
006 m o u
007 cr mn||||a|a||
008 190606s2017 xx obm 000 0 eng d
020 $a 9780355156706
035 $a (MiAaPQ)AAI10265784
035 $a (MiAaPQ)purdue:21085
035 $a AAI10265784
040 $a MiAaPQ $b eng $c MiAaPQ
100 1 $a Liu, Xingtao. $3 1187233
245 1 0 $a Mechanism of Grain Refinement of Aluminum By Al-5Ti-1B Master Alloy.
264 0 $c 2017
300 $a 1 online resource (67 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Masters Abstracts International, Volume: 56-06.
500 $a Adviser: Xiaoming Wang.
502 $a Thesis (M.S.)--Purdue University, 2017.
504 $a Includes bibliographical references
520 $a Grain refinement is a vital technique in aluminum (Al) casting industry, in which Al-5Ti-1B (5 wt. pct Ti and 1 wt. pct B) master alloy is often used as a grain refiner. Castablity and processability of aluminum can be enhanced substantially. Different theories of grain refinement were proposed in the past few decades, however, there is still no consensus on the mechanism of Al grain refinement. In this study, Al-5Ti-1B master alloy was diluted at different ratios. Scanning electron microscopes (SEM) are used for microstructure characterization. Based on microstructural analysis, it is speculated that a dynamic Ti-rich layer is formed on the surface of TiB2 particles to nucleate aluminum (alpha-Al) grains. But the Ti-rich layer will subsequently be dissolved through a peritectic reaction and release Ti atoms in to the aluminum matrix. A small amount of dissolution of TiB2 releases Ti atoms making a Al3Ti layer of a few atoms thick remain, contributing to the nucleation of alpha-Al grains. The rates of Al3Ti layer and TiB2 dissolution are different, so the appearance of Al 3Ti layer will be sporadic, forming a dynamic layer. Therefore, the nucleation and growth of Al3Ti phase is a dynamic process. Based on microstructure analysis, a dynamic nucleation theory is proposed in this investigation.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Materials science. $3 557839
650 4 $a Engineering. $3 561152
655 7 $a Electronic books. $2 local $3 554714
690 $a 0794
690 $a 0537
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a Purdue University. $b Engineering Technology. $3 1187234
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10265784 $z click for full text (PQDT)