Masaaki Ikawa

A vertical-type twin roll caster for aluminum alloy strips

A vertical-type twin roll caster for strip casting of aluminum alloys was devised and its properties were investigated. The strip, which was thinner than 3 mm, could be cast at speeds higher than 60 m/min. Features of the twin roll casters are as below. Copper rolls were used and lubricant was not used in order to increase the casting speed. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Separating force was very small in order to prevent sticking of the strip to the roll. Low superheat casting was carried out in order to improve microstructure of the strip. Roll casting of some kinds of aluminum alloys: A1050, A3004, A5083, A5182, A6063 and A356, were tried. Aluminum alloy, whose freezing zone is very wide like A5182, could be cast using the twin roll caster of the present study at speeds up to 150 m/min. Strips were thinner than 3 mm.

An Unequal Diameter Twin Roll Caster for Aluminum Alloys Casting

An unequal diameter twin roll caster was adopted for the strip casting of the aluminum alloys. The diameter of the upper roll was 250 mm, and that of the lower roll was 1000 mm. The width of the rolls was 100 mm. 6111 aluminum alloy strip was-cast at speeds of 5, 10 and 20 m/min. This caster could cast the strip at the speeds higher than the conventional twin roll caster. The start of casting was very easy. The strip did not stick to the roll without the lubricant. This was the effect of the low separating force. The microstructure of the 6111 was not a columnar structure but near to the equiaxed structure. This caster was adopted with closed top nozzle and side dam plate and cooling slope. Lower superheat casting was carried out using the cooling slope.