Takahiko Ichiki, Katsumi Miyamoto, Kazumi Katou
Today it is required to make multilateral efforts to streamline the production costs for current aluminum extrusion processes. We designed and developed an innovative core, which is superior in quality and tactful with attaching smoother inner surfaces to hollow ingots for extruded mandrel pipes, in the process of hot-top casting.
This core serves to bring about mass improvement in the surface smoothness inside a hollow ingot and the inner- surface microstructure. It turns out that lesser aluminum chips result from boring a hollow, preparatory to extrusion work, thereby creating a raise in the yield or the boring rate, and a drop in the production cost. Concurrently, the merits of hot-top casting remain equipped. Accordingly, its superiority to float casting (conventional technique) will be unaffected, namely, the inward quality of a hollow ingot to be produced.
This paper points out features and drawbacks of the hollow-ingot casting techniques, which have been put into practice or under study. It's another content covers structural standouts of the developed core and results of what was cast, using the same core. It is also discussed how to form smooth inner-surface texture with certainty and efficiency: the making of a core, setup of a core, and casting conditions.