ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
The semisolid processing technology is not widely used due to the high cost of raw materialand the equipment it requires. New low-cost raw materials and processes could be the key to expandthe use of this technology. This paper describes an initial effort to develop new Al-Si-Mg in terms ofraw material production and processing. The morphological evolution of all the alloys produced wascharacterized during their reheating to the semisolid state at 45 and 60% solid fraction, as well as thesemisolid behaviour in terms of viscosity versus shear rate. The adaptation of the semisolidtechnology to the thixoforming process via eccentric press was tested using an equipment up to 25tons. This type of equipment is not commonly employed in this kind of processing. Results indicatethat alloys with low silicon content, e.g., 2 or 4wt%Si, behave similarly to alloys with 7wt%Si, whichare normally used in the thixoforming process, with a viscosity of about 2 * 105 Pa.s. The semisolidbehaviour of low silicon alloys indicates the potential expansion of the range of raw materials for thisapplication. Thixoforming of semisolid materials in an eccentric press appears to be a very promisingtechnology, yielding parts that, despite their simplicity and restricted shape, display a very good finalmechanical behaviour
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/24/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.141-143.517.pdf
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