半凝固AC4CHアルミニウム合金高圧成形材の機械的性質に及ぼす熱処理条件の影響 Effect of heat treatment conditions on mechanical properties of semi-liquid AC4CH aluminum alloy high-pressure castings
In order to achieve an efficient mass-production system, a new semi-liquid casting process was developed that can produce a semi-liquid slurry, in individual metallic vessels, for each casting shot. In this research, the effect of heat treatment conditions was investigated on the mechanical properties and microstructures of stepped casting samples made by the new semi-liquid casting process and compared with that of squeeze cast samples. The semi-liquid castings showed a larger elongation and a slightly lower strength than squeeze castings. The larger elongation is due to the finer eutectic silicon structures formed under the higher cooling rate of semi-liquid slurry. The lower strength is considered to be the effect of the lower magnesium content in the primary-crystallized alpha phase. Castings made by the semi-liquid casting process seem to contain more Al–Si–Fe–Mg compounds, thus more magnesium is consumed to form these compounds than squeeze castings.
軽金属 58(8), 363-367, 2008-08-30
The Japan Institute of Light Metals