ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
Different techniques used to produce semi-solid alloys can result in different structures inthe material and, therefore, in distinct rheological behaviours which determine its thixo-formingability. Suitable raw materials to be used for SSM forming must present non-dendritic, very fine orfragmented structure in order to globularize without excessive agglomeration when re-heated to thesemi-solid state. This work analyses the influence of raw material production route on therheological behaviour of semi-solid A356 alloy. Techniques used were: electromagnetic stirring(EMS) and chemical ultra-refining (UR). Samples were re-heated to 580oC (~ 0.45 solid fraction)and hold for 0, 90 and 210s to allow the observation of the structure evolution. After structurescharacterization, the samples were submitted to compression tests, at δH/δt = 10mm/s, in the sametemperature/holding time conditions. Viscosity of the differently prepared raw material was relatedto the grain size, primary particle size, geometrical factor (roundness shape factor and contiguity)
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/22/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.116-117.565.pdf
Permalink
