RAPIDLY FORMING COMPLEX HOLLOW SHAPES USING LOST WAX INVESTMENT CASTING

摘要

A method for rapidly making up to 100,000castings of a complex hollow part using the same aluminumdie sets, the produced parts being fully durable andfunctional parts; the method combines the rapid coremaking and core removal capabilities of resin bonded sandor salt cores and the rapid pattern making capabilitiesof the lost wax investment casting technique; the processallows for modifying the interior flow characteristics ofan engine head without need for changing the exteriorshape of such head, leading to nimble manufacturing ofengine families; the method comprises (a) making anassembly of articulate bonded sand or salt cores eachspaced from one another, one core of which arcuatelyencompasses at least one end of another core to define atleast one hidden space therebetween; (b) making an easilymachined die set to receive and support the assembly ofcores in spaced relation for defining a part cavityaround and between the cores, including the hidden space;(c) injecting fluidized wax into the cavity with acontrolled sustained pressure to fill the cavity withoutentrapping gases and form a pattern of the casting; (d)using the wax pattern with the assembly of cores thereinto form a shell mold thereabout and to form a metalcasting in the mold with the cores still in place, and(e) removing from the casting all of the particulatecores of the assembly by reversing the bond between thecore particles to form a collection of particles that arefreely flowable under normal gravity.