| 摘要 |
<p>Method of and apparatus for making metal castings using a polystyrene pattern (10) embedded in unbonded sand (20) which is consolidated to form a mould (M) in which is defined a mould cavity (C). Molten metal is fed into the cavity (C) and permitted to solidify to form a casting (11). The metal is aluminium or an aluminium alloy and at least part of the mould is formed of sand which comprises at least 50% zircon sand, or other particulate material suitable for making a mould and having a bulk density lying in the range 2-3 grams/cc. The mould (M) may have a moulding feature (9) having upper and lower surfaces for contact with the metal and which projects inwardly of the mould cavity (C) from the main wall thereof and the length of any one section of the moulding feature (9) being at least twice the thickness of the thinnest part thereof by which the section is connected to the main wall of the mould cavity.</p> |
