摘要 |
A ceramic material for making ceramic moulds and core for metal casting is described comprising basically granular or bubble refractory material, eg. alumina or mullite, bound together by hardened ceramic slurry. Moulds for lost wax casting are built-up by dipping a wax pattern in ceramic slurry and then applying granules of bubble alumina in an all over coating. A plurality of such coats may be applied by allowing the slurry to harden between applications. The moulds are more insulating than those using tubular alumina grits, for example, and produce castings with smoother surface finishes. |