ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
A semi solid thin strip continuous casting process was used to obtain 50%wtPb/50%wtSn strip by single and twin roll processing at speed of 15 m/min. A 50%wt Pb/50%wtSnplate ingot was also cast for rolling conventionally into strips of 1.4 mm thickness and 45 mm widthfor comparison with those achieved non-conventionally. This hypoeutectic alloy has a solidificationinterval and fusion temperature of approximately 31°C and 215°C respectively. The casting alloytemperature was around 280°C as measured by a type K immersion thermocouple prior to pouringinto a tundish designed to maintain a constant melt flow on the cooling slope during semi solidmaterial production. A nozzle with a weir ensures that the semi solid material is dragged smoothlyby the lower roll, producing strip with minimum contamination of slag/oxide. The temperatures ofthe cooling slope and the lower roll were also monitored using K type thermocouples. The coiledsemi solid strip, which has a thickness of 1.5 mm and 45 mm width, was rolled conventionally inorder to obtain 1.2 mm thick strip. The coiled thixorolled strip had a thickness of 1.2 mm andachieved practically the same width as the conventional strips. Blanks of 40 mm diameter were cutfrom the strips in a mechanical press, ready for deep drawing and ironing for mechanicalcharacterization. All the strips achieved from non-conventional processing had the same mechanicalperformance as those achieved conventionally. The limiting drawing ratio (LDR) achieved wasapproximately 2.0 for all strips. Microscopy examination was made in order to observe phasesegregation during processing
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/24/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.141-143.49.pdf
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