The influence of cooling rate on microstructure, tensile and fatigue behavior of heat treated Al-Si-Cu-Mg alloys
2017 (English)In: Liquid metals and alloys: From structure to industrial applications / [ed] Lars Arnberg, Franco Bonollo and Roberto Montanari, Trans Tech Publications, 2017, 81-92 p.Chapter in book (Refereed)
Al-Si-Mg alloys are commonly employed for the production of automotive castings. In view of the recent stringent emissions standards and consequent engine downsizing, these components must withstand higher temperatures and stresses than in the past. In this regard, the heat treatable quaternary Al-Si-Cu-Mg alloys gained particular interest in recent years, due to their superior mechanical properties and higher thermal stability. The present research activity was addressed to evaluate the influence of cooling rate on microstructure and consequently on room temperature tensile and fatigue behaviour of the A354 and C355 alloys. Samples for mechanical tests were produced under controlled cooling rates, in order to induce different secondary dendrite arm spacing (SDAS) values, classified as fine (20-25μm) and coarse (50-70μm). The experimental results showed that the cooling rate strongly influences the type, size and morphology of intermetallic particles. The presence of coarse intermetallic phases, mostly Fe-based, observed in coarse SDAS specimens, was reported to strongly affect ultimate tensile strength (UTS), elongation to failure and fatigue strength of both the investigated alloys. A correlation between UTS and fatigue resistance was found, independent of microstructural coarseness.
Place, publisher, year, edition, pages
Trans Tech Publications, 2017. 81-92 p.
Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752 ; 884
Al-Si-Cu-Mg alloys, cooling rate, casting, microstructure, intermetallics, mechanical properties
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:hj:diva-34155DOI: 10.4028/www.scientific.net/MSF.884.81ScopusID: 2-s2.0-85011067796ISBN: 978-3-03835-640-0 (print)ISBN: 978-3-0357-0121-0 (electronic)OAI: oai:DiVA.org:hj-34155DiVA: diva2:1051462