Modified rheological processing technology and
its applications in iron and steels
(Research Center of Semisolid Metal Processing, Beijing Jiaotong University, Beijing 100044, China)
Abstract: A traditional semisolid processing based on the rheological properties of semisolid alloy is very difficult in manufacturing the semisolid slurry because of the chase for spherical, fine and high solid fraction of the primary solid in the slurry. Through many experiments, it is found that it is not very necessary to excessively emphasize the glomeration and high solid fraction considering of the facts that the rheological properties of the semisolid slurry is controlled by not only the microstructure of the primary solid but also the rheological conditions. The manufacturing slurry can be simply regarded as preparing the semisolid alloy melt, therefore, a modified semisolid processing technology is presented. Its procedure consists of three basic steps, such as preparing slurry，filling mould cavity and solidification with pressure. The basic aim of the preparing slurry is to obtain the slurry containing 5%−20% (volume fraction) primary solid with particle or stick instead of spherical morphology. The experiment results show that, with the modified rheological processing technology, many steel and nonferrous alloy products are industrially produced.
Key words: semisolid alloy; steel; rheology processing; slurry; squeeze casting; solid fraction