リンフラックスとナトリウムフラックスの同時添加による過共晶Al-Si合金の改良

抄録

An experimental investigation was made for effects of simultaneous addition of phosphate (P-) flux and sodium halide (Na-) flux upon the cast structure and mechanical properties of hypereutectic Al-19%Si alloys. The fluxes introduced into alloy melts were P-flux (90(NaPO₃)₆-10Al₂O₃) and Na-flux (50NaF-50NaCl) which are effective, respectively, for refining the primary Si crystal and for modifying the eutectic Si crystal. The simultaneous addition of P- and Na-flux was effected by use of a composite P-Na-flux prepared by mixing both the component fluxes in weight ratio 1: 1 and 1: 2 and fusing the mixture in union. The P-Na-flux, when containing the component fluxes in some adequate weight ratios, is capable of producing such alloys as are composed in structure of fine grain primary Si crystals and modified eutectic Si crystals, of improving the tensile strength up to a level comparable with that achieved by the P-flux addition, and of improving the breaking elongation more than either the P- or Na-flux singly added.