Effect of microstructure and overaging on the tensile behaviour at room and elevated temperature of C355-T6 cast aluminum alloyShow others and affiliations
2015 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 83, p. 626-634Article in journal (Refereed) Published
Abstract [en]
The present study was focused on the microstructural and mechanical characterization of the Al–Si–Cu–Mg C355 alloy, at room and elevated temperature. In order to evaluate the influence of microstructural coarseness on mechanical behavior, samples with different Secondary Dendrite Arm Spacing (SDAS) (20–25 μm for fine microstructure and 50–70 μm for coarse microstructure), were produced through controlled casting conditions. The tensile behavior of the alloy was evaluated at T6 condition and at T6 with subsequent high temperature exposure (41 h at 210 °C, i.e. overaging), both at room and elevated temperature (200 °C). Microstructural investigations were performed through optical and electron microscopy.
The results confirmed the important role of microstructure on the tensile behavior of C355 alloy. Ultimate tensile strength and elongation to failure strongly increased with the decrease of SDAS. Larger SDAS, related to lower solidification rates, modify microstructural features, such as eutectic Si morphology and size of the intermetallic phases, which in turn influence elongation to failure. Overaging before tensile testing induced coarsening of the strengthening precipitates, as observed by STEM analyses, with consequent reduction of the tensile strength of the alloy, regardless of SDAS. A more sensible decrease of tensile properties was registered at 200 °C testing temperature.
Place, publisher, year, edition, pages
2015. Vol. 83, p. 626-634
Keywords [en]
C355; Al–Si–Cu–Mg alloys; Tensile properties; SDAS; High temperature; Overaging
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:hj:diva-27143DOI: 10.1016/j.matdes.2015.06.031ISI: 000359329000072Scopus ID: 2-s2.0-84941275373Local ID: JTHMaterialISOAI: oai:DiVA.org:hj-27143DiVA, id: diva2:820415
2015-06-122015-06-122017-12-04Bibliographically approved