Influence of nano-structured silanols on the microstructure and mechanical properties of a4047 and a359 aluminum casting alloys

Andre Lee, Yang Lu, Allen Roche, Tsung Yu Pan

Research output: Contribution to journalArticle

Abstract

Minor alloying elements present in aluminum silicon-based casting alloys, such as sodium, strontium, or boron-titanium, could eventually affect the alloy's microstructure and hence its mechanical properties. However, difficulties in balancing strength, ductility, and the subsequent precipitation strengthening heat treatment remain. The effects of nano-structured silanols based on partially condensed polyhedral oligomeric silsequioxanes (POSS-silanol) on the microstructure and mechanical properties of A4047 and A359 aluminum alloys were studied using a ''twostep'' process technique. The silanols react with active aluminum surface to form stable Si-O-Al bonds, while cage-like POSS core enables control of subsequent solidification process leading to desired mechanical performance. Using standard casting approach, the increase of both ductility and the tensile strength of the A4047 and A359 alloys is due to a highly refined fine fibrous of eutectic Al-Si formed instead of the irregular flakes as well as a refined primary aluminum phase as compared to the unmodified alloys. It has been found that this newly developed approach can also be expanded to other heat-treatable casting aluminum alloys with specific interest on changes in the microstructure of both primary aluminum phase and eutectic constituent.

LanguageEnglish (US)
Pages322-328
Number of pages7
JournalInternational Journal of Metalcasting
Volume10
Issue number3
DOIs
StatePublished - Jul 1 2016

Profile

Aluminum castings
Aluminum
Mechanical properties
Casting
Microstructure
Eutectics
Ductility
Aluminum alloys
Strontium
Boron
Strengthening (metal)
Silicon
Alloying elements
Titanium
Solidification
Tensile strength
Sodium
Heat treatment
silanol

Keywords

  • A359
  • A4047
  • Aluminum casting alloys
  • Modification
  • Silanol
  • Solidification

ASJC Scopus subject areas

  • Mechanics of Materials
  • Industrial and Manufacturing Engineering
  • Materials Chemistry
  • Metals and Alloys

Cite this

Influence of nano-structured silanols on the microstructure and mechanical properties of a4047 and a359 aluminum casting alloys. / Lee, Andre; Lu, Yang; Roche, Allen; Pan, Tsung Yu.

In: International Journal of Metalcasting, Vol. 10, No. 3, 01.07.2016, p. 322-328.

Research output: Contribution to journalArticle

@article{791b15223b6d4cfbad9b387b1a0051ab,
title = "Influence of nano-structured silanols on the microstructure and mechanical properties of a4047 and a359 aluminum casting alloys",
abstract = "Minor alloying elements present in aluminum silicon-based casting alloys, such as sodium, strontium, or boron-titanium, could eventually affect the alloy's microstructure and hence its mechanical properties. However, difficulties in balancing strength, ductility, and the subsequent precipitation strengthening heat treatment remain. The effects of nano-structured silanols based on partially condensed polyhedral oligomeric silsequioxanes (POSS-silanol) on the microstructure and mechanical properties of A4047 and A359 aluminum alloys were studied using a ''twostep'' process technique. The silanols react with active aluminum surface to form stable Si-O-Al bonds, while cage-like POSS core enables control of subsequent solidification process leading to desired mechanical performance. Using standard casting approach, the increase of both ductility and the tensile strength of the A4047 and A359 alloys is due to a highly refined fine fibrous of eutectic Al-Si formed instead of the irregular flakes as well as a refined primary aluminum phase as compared to the unmodified alloys. It has been found that this newly developed approach can also be expanded to other heat-treatable casting aluminum alloys with specific interest on changes in the microstructure of both primary aluminum phase and eutectic constituent.",
keywords = "A359, A4047, Aluminum casting alloys, Modification, Silanol, Solidification",
author = "Andre Lee and Yang Lu and Allen Roche and Pan, {Tsung Yu}",
year = "2016",
month = "7",
day = "1",
doi = "10.1007/s40962-016-0044-4",
language = "English (US)",
volume = "10",
pages = "322--328",
journal = "International Journal of Metalcasting",
issn = "1939-5981",
publisher = "American Foundry Society",
number = "3",

}

TY - JOUR

T1 - Influence of nano-structured silanols on the microstructure and mechanical properties of a4047 and a359 aluminum casting alloys

AU - Lee,Andre

AU - Lu,Yang

AU - Roche,Allen

AU - Pan,Tsung Yu

PY - 2016/7/1

Y1 - 2016/7/1

N2 - Minor alloying elements present in aluminum silicon-based casting alloys, such as sodium, strontium, or boron-titanium, could eventually affect the alloy's microstructure and hence its mechanical properties. However, difficulties in balancing strength, ductility, and the subsequent precipitation strengthening heat treatment remain. The effects of nano-structured silanols based on partially condensed polyhedral oligomeric silsequioxanes (POSS-silanol) on the microstructure and mechanical properties of A4047 and A359 aluminum alloys were studied using a ''twostep'' process technique. The silanols react with active aluminum surface to form stable Si-O-Al bonds, while cage-like POSS core enables control of subsequent solidification process leading to desired mechanical performance. Using standard casting approach, the increase of both ductility and the tensile strength of the A4047 and A359 alloys is due to a highly refined fine fibrous of eutectic Al-Si formed instead of the irregular flakes as well as a refined primary aluminum phase as compared to the unmodified alloys. It has been found that this newly developed approach can also be expanded to other heat-treatable casting aluminum alloys with specific interest on changes in the microstructure of both primary aluminum phase and eutectic constituent.

AB - Minor alloying elements present in aluminum silicon-based casting alloys, such as sodium, strontium, or boron-titanium, could eventually affect the alloy's microstructure and hence its mechanical properties. However, difficulties in balancing strength, ductility, and the subsequent precipitation strengthening heat treatment remain. The effects of nano-structured silanols based on partially condensed polyhedral oligomeric silsequioxanes (POSS-silanol) on the microstructure and mechanical properties of A4047 and A359 aluminum alloys were studied using a ''twostep'' process technique. The silanols react with active aluminum surface to form stable Si-O-Al bonds, while cage-like POSS core enables control of subsequent solidification process leading to desired mechanical performance. Using standard casting approach, the increase of both ductility and the tensile strength of the A4047 and A359 alloys is due to a highly refined fine fibrous of eutectic Al-Si formed instead of the irregular flakes as well as a refined primary aluminum phase as compared to the unmodified alloys. It has been found that this newly developed approach can also be expanded to other heat-treatable casting aluminum alloys with specific interest on changes in the microstructure of both primary aluminum phase and eutectic constituent.

KW - A359

KW - A4047

KW - Aluminum casting alloys

KW - Modification

KW - Silanol

KW - Solidification

UR - http://www.scopus.com/inward/record.url?scp=84978045348&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84978045348&partnerID=8YFLogxK

U2 - 10.1007/s40962-016-0044-4

DO - 10.1007/s40962-016-0044-4

M3 - Article

VL - 10

SP - 322

EP - 328

JO - International Journal of Metalcasting

T2 - International Journal of Metalcasting

JF - International Journal of Metalcasting

SN - 1939-5981

IS - 3

ER -