Processing of thin metal strip by casting-cum-rolling

Rolling is a process of reducing the thickness or changing the cross-section of a long work-piece by compressive forces applied through a set of rolls. It accounts for about 90% of all metals produced by metal working processes and is a conventional method to produce metal strip. This process involves several processing steps resulting in high production cost and interior productivity. A approach by casting-cum-rolling process has been developed in this paper. An apparatus has been built which consists of casing unit and melt delivery unit for this process. A forming belt and the two pinch rolls are utilized in the casting unit. An extended contacting point between forming belt and the lower pinch roll in this unit makes it possible to cast thin metal strips of alloys with wider freezing range. Tin alloy, aluminium alloys and magnesium alloys had been tested on the apparatus. The results showed that it was feasible to produce crack-free cast strips of tin alloy and aluminium alloys. However, crack region was found in magnesium strip, which possibly attributed to slow solidification rate and non-uniformity temperature and melt distribution. Effects of processing parameters on the surface roughness and strip thickness were studied too. It was found that the texture of cast strips on their roll sides was less affected by the processing parameters. Their surface roughness was inherited from the roll surface condition. The strips' texture on their belt side, however, was closely dependent on the processing parameters. The average cast strip thickness made of tin, aluminium and magnesium alloy is 0.31 mm, 0.95 mm and 1.17 mm, respectively.