The fluidity of Al-Mn alloy was evaluated by a vertical suction fluidity measurement method. The fluidity measurement and microstructure analysis were carried out on Al-1, 1.5, 2, 3 and 5 mass % Mn alloys. The fluidity length of Al-Mn alloys increases in accordance with the temperature of the molten metal. The increase in the Mn additive content decreases the fluidity length of Al-Mn alloys. Al-1, 1.5, 2 and 3 mass % Mn alloys showed a gradual reduction of the fluidity length in accordance with the amount of the Mn additive content. However, 5 mass % Mn alloy showed a substantial drop in the fluidity. It is considered that skin formation solidification causes the flow cessation mechanism of Al-1, 1.5, 2 and 3 mass % Mn alloys. In the case of the 5 mass % Mn alloy, the cessation is caused by mushy solidification.

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  The water absorption percentage of oolitics sand, which was made by the changing green sand binder and burning temperature, was measured. Bentonite was added to the oolitics sand to make the green sand, and then water absorption percentage was calculated from the relation between the green sand with bentonite and compactability. The oolitics formation was also observed by SEM to investigate the mechanism of water absorption. The results showed that oolitics is formed from thin layers and microporosity which change when the condition of green sand binder and burning temperature are changed. Water absorption was found to occur mainly between the thin layers. As the thin layers closed, the water absorption percentage dropped.

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  Recently, several new simulation methods using the non-orthogonal element have been developed to preserve the original shape of a casting in its simulation model. However, the CFL number, which is one of the most important parameters for decreasing the consumption of the calculation time, is restricted to preserve the accuracy of the calculation in many of these methods. In this paper, a new mold filling simulation method based on the Galerkin method is proposed. It adopts the CIP (Cubic Interpolated Propagation) method in the governing equations to trace the surface of the liquid as accurately as possible. 3-D mold filling simulation in a circular disk with a gate and runner is demonstrated as the numerical example. The numerical result shows that the change of the main flow direction is caused by the pressure gradient force generated near the gate.

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  The alloying of ductile cast iron with Cu and Ni is effective for the structural control in austemper heat treatment. Use of this type of cast iron is provided to produce cast iron materials with extremely high toughness and strength. In this study, the effects of austempering conditions and the addition of Cu and Ni on toughness of ductile cast iron are investigated. In austemper heat treatment, impact absorbed energy is increased by raising the austempering temperature. However, at high austempering temperatures exceeding 3.6 ks at 673K. the formation of fine pearlite proceeded, resulting in a marked decrease in the impact absorbed energy. Addition of Cu-Ni in the cast iron resulted in greater impact absorbed energy and tensile strength at any temperature during the austempering treatment. It depends on the suppression of precipitation beginning of fine pearlite and the stabilization of retained austenite. Furthermore, this cast iron alloy reduced the change in impact absorbed energy and tensile strength, induced during the austempering time.

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  Static and dynamic bending tests of ferritic spheroidal graphite cast iron were carried out at temperatures range from room temperature to 77K. Bending load-time curves obtained by using instrumented Charpy impact testing machine are converted to load-deflection curves. The relationship between bending load P and deflection δ is well expressed by P=Dδⁿ in both of static and dynamic tests, where D and n’ are constants. D and n’ obtained are both larger than the expected respectively. Constant D in dynamic test is larger than that in static at the same temperature by 17%, regardless of the testing temperature. This difference coincides pretty well with the measured strain rate exponent of flow stress 0.0103. The critical deflection just before fracture δ_c, is proportional to fracture strain of specimen at loading point. Fracture energy W, the area surrounded by the load-deflection curve and abscissa graphically, can be numerated by W = Pmδ_c / (1 + n’), where P_m denotes the maximum bending load. The strain rate dependence of transition temperature for the iron seems roughly similar to that of steel.

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  The ferritizing process of high purity cast iron was investigated. Specimens used for the experiments were pure Fe-C-Si, Fe-C-Si-P, Fe-C-Si-S, Fe-C-Si-P-S alloys and commercial grade cast iron. The specimens used for the investigation were packed in a container with electrode graphite and fully annealed during two stages in air or argon atmospheres. The first stage was fixed at 1173K for 3 hours while the second stage, the cooling stage from 1173K to 973K was performed at various times such as 5, 10, 20, 40, 80 hours. The results obtained were as follows : 1) The ferritization of pure alloy is difficult to compare with that of commercial grade cast iron. 2) The pure alloys are ferritized easily in argon atmosphere annealing. 3) The titanium in the commercial grade cast iron combines with the nitrogen in iron to form TiN. As it decreases the effect of nitrogen on pearlitization, the ferritization is accelerated. 4) Due to the low Ti content of pure alloys, nitriding occurs when heat treatment is performed, thus preventing ferritization. 5) The ferritizing speed of the specimens decreases in the following order C. G. , 7P, 7P-4S, B, 4S.

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  Recently, surface scrubbing mostly reclaims waste sand in foundries. There are 3 types of reclamation methods impact, friction and grindstone. In this study, we tested 7 new types of silica sand by grindstone method to investigate the relation between the material characteristic of silica sand and reclamation. The results showed that silica sand was tended to be more easy-to-grind when the loose bulk specific gravity was high. We also found that the grain shape and true specific gravity of silica sand, but not the latter half affected the first half of reclamation. Correlation was seen between the mold strength, bulk density, SiO₂, and total clay after reclamation.

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