IMPROVED SOUNDNESS AND MECHANICAL PROPERTIES OBTAINED BY SOLIDIFICATION UNDER PRESSURE IN A206

摘要

The goal of this study is to achieve forging properties with the benefits of cast structural components. The effect of applying 10 atmospheres of pressure during solidification on the soundness and mechanical properties of A206 aluminum was studied. Experimental wedge shaped castings were solidified in no-bake molds at 1 and 10 atmospheres pressures. A wedge shaped casting provided a range of porosity and controlled solidification front. Radiography verified that pressure increased soundness by an order of magnitude. Tensile coupons were removed from areas with selected cooling rates. Elongation improved by ～50 to 550% and tensile strength increased ～11 to 60% when the casting was pressurized during solidification. Similar improvements in cast properties of other alloys are possible under the correct metallurgical conditions. This paper discusses how to achieve these metallurgical conditions for complex three-dimensional production castings.