Papers in JOURNAL OF THE JAPAN SOCIETY FOR TECHNOLOGY OF PLASTICITY
(Vol.42 No.479 December 2000)
Fabrication of Clad Parts by Semi-Molten Processing
Tohru SHIROTA, Tasuku DENDO, Takashi KIMURA and Beom-Suck HAN
(Received on January 19, 2000)
Some attempts at the fabrication of clad parts were made by semi-molten processing. In this process, semi-molten metal inserted into a solid hollow metal is pressurized in a shaped die with a punch through aperture of the hollow metal, and deformed plastically together with the hollow metal. During deformation, the semi-molten metal acts as a pressure medium and the hollow metal is bulge-formed by the internal pressure. After solidification of the semi-molten metal, the clad part which is covered with a dissimilar metal, i.e., the hollow metal, is fabricated. The feasibility of this process was confirmed through experiments in which several kinds of Al-Si alloy were adopted as the semi-molten metal, and aluminum, copper and stainless steel (SUS304) pipes were used as the hollow metal. In this study, formability of the outer metal, bondability between the outer and inner metals and morphology of the inner metal were examined with respect to process parameters such as solid fraction and degree of bulge-forming.
Key words : new forming process, clad material, semi-molten metal, bulging, joining
Fabrication of Aluminum Alloy Ingots for Thixo-forming
Using a Cooling Slope
Toshio HAGA
(Received on January 25, 2000)
A simple process of using a cooling slope to fabricate aluminum alloy ingots for thixo-forming was proposed. Features of this process were investigated. The ingot for thixo-forming could be fabricated only by solidifying the semisolid slurry which was made by pouring melt on the cooling slope. The primary crystal and eutectic Si of an Al-6mass%Si ingot cast using this process became globular after reheating up to a semisolid temperature. The solid fraction of the semisolid slurry and cooling rate of the ingot were important factors that affected the shape of the primary crystal and the mechanical properties.
Key words : semisolid processing, mashy state forging, thixo-forming, cooling slope, semisolid casting
Semi-Solid Strip Casting of Aluminum Alloys
Toshio HAGA
(Received on January 25, 2000)
A melt drag twin-roll caster (MDTRC) and a melt drag belt-roll caster (MDBRC) were developed for semisolid strip casting of aluminum alloys. These casters were equipped with a cooling slope to cast strips from semisolid slurry. The MDTRC was suitable for semisolid strip casting of mashy solidification aluminum alloys. The MDTRC could cast Al-12mass%Si strips from melt at speeds up to 100m/min by semisolid forming at the upper surface of the strip without using the cooling slope. Elongation of Al-6mass%Si strips was improved up to 30% through semisolid strip casting using the MDTRC equipped with the cooling slope. Semisolid strip casting of A1050 could be achieved using the MDBRC equipped with the cooling slope. The primary crystal of the A1050 strip cast from semisolid slurry became globular.
Key words : semisolid processing, direct rolling, semisolid strip casting, twin-roll caster, cooling slope, melt drag twin-roll caster, melt drag belt-roll caster