Cargando…

A Personal View of Microstructure and Properties of Al Alloys

This paper presents a personal view by the author of the role of bifilms in Al alloys. The mantra ‘microstructure determines properties’ is widely accepted as a truism, but is here critically assessed and found wanting. The case is made that bifilms from the casting process, while often invisible in...

Descripción completa

Detalles Bibliográficos
Autor principal: Campbell, John
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7962965/
https://www.ncbi.nlm.nih.gov/pubmed/33800451
http://dx.doi.org/10.3390/ma14051297
_version_ 1783665551091957760
author Campbell, John
author_facet Campbell, John
author_sort Campbell, John
collection PubMed
description This paper presents a personal view by the author of the role of bifilms in Al alloys. The mantra ‘microstructure determines properties’ is widely accepted as a truism, but is here critically assessed and found wanting. The case is made that bifilms from the casting process, while often invisible in the microstructure, are usually at least as important, if not of far greater importance, because they are often present as a dense population of cracks throughout the metal. The bifilm population controls the morphology of many features of cast and wrought structures. For cast alloys, bifilm control of pore morphology and Si morphology in Al–Si alloys is discussed, as is dendrite arm spacing (DAS). The tensile property benefits of grain refinement are seen to be mainly bifilm controlled. The properties ductility and fatigue appear to be especially dominated by bifilm content, as are invasive corrosion processes such as pitting, intergranular corrosion, hydrogen blistering and cracking. Bifilm control is proposed as a new concept permitting the improvement and control of metallurgical properties.
format Online
Article
Text
id pubmed-7962965
institution National Center for Biotechnology Information
language English
publishDate 2021
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-79629652021-03-17 A Personal View of Microstructure and Properties of Al Alloys Campbell, John Materials (Basel) Review This paper presents a personal view by the author of the role of bifilms in Al alloys. The mantra ‘microstructure determines properties’ is widely accepted as a truism, but is here critically assessed and found wanting. The case is made that bifilms from the casting process, while often invisible in the microstructure, are usually at least as important, if not of far greater importance, because they are often present as a dense population of cracks throughout the metal. The bifilm population controls the morphology of many features of cast and wrought structures. For cast alloys, bifilm control of pore morphology and Si morphology in Al–Si alloys is discussed, as is dendrite arm spacing (DAS). The tensile property benefits of grain refinement are seen to be mainly bifilm controlled. The properties ductility and fatigue appear to be especially dominated by bifilm content, as are invasive corrosion processes such as pitting, intergranular corrosion, hydrogen blistering and cracking. Bifilm control is proposed as a new concept permitting the improvement and control of metallurgical properties. MDPI 2021-03-08 /pmc/articles/PMC7962965/ /pubmed/33800451 http://dx.doi.org/10.3390/ma14051297 Text en © 2021 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Review
Campbell, John
A Personal View of Microstructure and Properties of Al Alloys
title A Personal View of Microstructure and Properties of Al Alloys
title_full A Personal View of Microstructure and Properties of Al Alloys
title_fullStr A Personal View of Microstructure and Properties of Al Alloys
title_full_unstemmed A Personal View of Microstructure and Properties of Al Alloys
title_short A Personal View of Microstructure and Properties of Al Alloys
title_sort personal view of microstructure and properties of al alloys
topic Review
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7962965/
https://www.ncbi.nlm.nih.gov/pubmed/33800451
http://dx.doi.org/10.3390/ma14051297
work_keys_str_mv AT campbelljohn apersonalviewofmicrostructureandpropertiesofalalloys
AT campbelljohn personalviewofmicrostructureandpropertiesofalalloys