Investment casting, also know as lost wax casting is regarded as a precision casting process to fabricate near-net-shaped with components requiring complex shapes , often thin-wall , products which may not require future machining with accuracy, repeatability, versatility and integrity in a variety of metals and high-performance alloys.
Investment castings offer complex internal geometries, significant weight reduction opportunities, and unlimited alloy choices for the ultimate in design flexibility.
The reduction or elimination of secondary machining allows us to easily convert multi-part assemblies into single, as-cast parts with high rates of repeatability. Thin wall capabilities, smooth surface finishes, and consistent dimensional accuracies make investment casting the simple solution to complex engineering.
Wax is injected into an aluminum die to produce a pattern that is an exact replica of the part to be produced. For every casting, a wax pattern must be manufactured. The patterns are clustered around a coated sprue and repeatedly dipped into an agitated vat of ceramic and allowed to dry. After a shell thickness of approximately 3/16" has been built; the molds are dewaxed by either flash firing at high heat (1400 F.) or autoclaving (pressure and steam). The hollow shells are then preheated to 800-2000 F.depending on the alloy to be poured and the molten metal cast immediately into the hot shell. After cooling, the ceramic is vibrated and blasted off the metal parts and discarded. The balance of the cleaning operations (cut off, grind, heat treat, straightening, blast) are straight forward and quite similar to the other casting processes.
The investment casting process or lost wax process produces near-net-shape configurations. This offers engineers and designers freedom of design in many types of alloys. This process is capable of producing precise detail and dimensional accuracy in parts weighing many pounds to just a few ounces. Precision investment castings are able to reduce costs in many cases due to reduced machining and less materiel waste.
Any castable alloy can be used, including ones that are impossible to forge or are too difficult to machine. Further, the cost of the alloy is less important in the final price of an investment casting than in many other metal forming processes; therefore an upgraded alloy can be specified (especially if the part is redesigned to save weight) at little or no increase in price.
Investment casting can reduce costly machining operations and sometimes even eliminate them. Investment castings are produced to close tolerances and near-net size. There is little secondary machining required, thus offering savings in machining time and material costs.
The investment casting process produces a reliable and consistent product. Our process control system yields remarkable consistency from part to part as well as from batch to batch. This reproducibility feature means our customers will save time in both machine set up and assembly.
In addition to complex and demanding parts, investment castings also produces many very simple parts competitively. This capability is often made possible by low tooling costs associated with investment castings. Investment castings are competitively produced in sizes ranging from a few grams to more than 300 kg (660 lb) and the upper limits continue to increase.