Rapidly forming complex hollow shapes using lost wax investment casting

摘要

A method of repetitively forming rapid prototype metal castings that are fully durable and functional metal parts of a complex shape, comprising the steps of: (a) making an assembly (10) of resin-bonded particulate cores (11,12,13) spaced from each other, one core arcuately encompassing at least one end of another core to define at least one hidden space (31,32) therebetween; (b) making an easily machined die set (18) to receive and support said assembly (10) of cores in spaced relation for defining a casting cavity (34) around and between said cores, including said at least one hidden space (31,32); (c) injecting fluidised wax into said cavity (34) under a controlled sustained pressure to fill said cavity without entrapping gases and to form a wax pattern (37) for the casting; (d) using said wax pattern (37) with said assembly (10) of cores therein to form a shell mould (40) thereabout and thence draining the wax from the mould to permit a metal casting (43) to be formed in place of the wax pattern (37) with the assembly (10) of cores still in place, and (e) removing from the casting all of the particulate cores (11,12,13) in said casting by reversing the bond between said core particles to form a collection of particles that is freely flowable under gravity.