| 摘要 |
A method of making aluminum castings having a self-fused high silicon content in the interior matrix near and at the surface. A sand core is coated with a tacky, low-ash, low-volatile adhesive along a predetermined zone. Silicon dust particles are deposited on said adhesive in bonded relation. Molten aluminum is cast into a mold cavity containing the coated core. After mold stripping, the silicon particles are exposed as metallurgically bonded to the aluminum but along an ultra-thin depth. At least some of the exposed silicon particles are machined to expose a planar facet and thereby increase the projected exposure of the silicon particles along the machined plane. The resulting product has a reduced shrinkage characteristic (typical of aluminum alloys having a high proportional precipitated silicon). |
