ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
The morphology of semi-solid alloy is one of the key influence factors on the rheologicalbehavior of slurry during die filling and the mechanical properties of formed parts. However, it isdifficult to study such effect due to hard controlling of morphology in semi-solid state. In this paper,a self-developed Searle-type viscometer was used to determine the rheological behavior of A356aluminum alloy in different morphology, which was refined with the salts mixture of K2TiF6 andKBF4. The results indicated that the flow behavior of refined A356 alloy in the semi-solid statepossesses obviously thixotropic behavior under isothermal shearing condition with less time toreach steady state and lower steady apparent viscosity as compared to that of the A356 alloy. Duringcontinuous cooling at a constant shearing rate, the apparent viscosity of refined A356 slurry in thesame solid fraction decreased with the content of Ti. It is shown from quantitative image analysisthat the primary α-Al grain in the refined alloy evolves from dendrites to rosettes or sphericitys, andthen tends to be rounder and finer in higher Ti content. The mechanism of the influence ofmorphology on rheological behavior was also discussed in this paper
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/22/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.116-117.601.pdf
Permalink
