Rapid cooling procedure for forming metal alloys from powders uses flattened hyperboloid tube positioned close to outlet of gas atomiser

摘要

The procedure consists of positioning a cooler in the form of flattened hyperboloid Laval tubes at a short distance (less than 50 cm) from the end of a gas atomiser pipe discharging an atomised metal or alloy with an amorphous or nano-crystalline structure. The atomiser has a supersonic ejection velocity and ejects gas at a negative temperature so that it is below 250 degrees K inside the cooler. In a variant the narrowest part of the hyperboloid tubes is replaced by two rotating cylinders.