Al-Si合金鋳塊中の水素拡散とミクロ組織の関係
1992 年 42 巻 6 号 p. 333-338
詳細
1992 年 42 巻 6 号 p. 333-338
Hydrogen diffusivity in Al-(2-18 mass%)Si alloys melted in air were measured by a desorption technique which was an outgassing study from cylindrical samples. The diffusivity of D1 for as-cast samples were decreased to D2 for hydrogen-charged samples. The differences between D1 and D2 were enlarged for lower temperatures and for the more eutectic at higher silicon concentration. The decreasing of diffusivity from D1 to Dv2 by heating was due to a morphogy change of eutectic silicon, from two reasons, one of which is a loss of long-range enhanced diffusion path along surfaces on plate-like particles of eutectic silicon for as-cast samples and the other reason is a grow-up of hydrogentrapping at coagulated and isolated particles of silicon. A downward aberration of diffusivity at around 400°C was related to a hydrogen trapping by small silicon particles precipitated from a supersaturated alpha-aluminum solid solution.
