Precision Investment Casting of Wax Patterns for Castings

The Process of Investment Casting

Investment casting includes processes such as wax pressing, wax repairing, tree assembly, slurry coating, wax melting, casting metal liquid, and post-treatment. Investment casting is a process of making a wax mold of the desired part, and then coating the wax mold with mud, which forms the ceramic shell. After the ceramic shell is dried, it is put into hot water to melt the internal wax mold. The ceramic shell that has removed the melted wax mold is then fired into a ceramic mold. Once fired, the pour spout is usually left in place from the original ceramic mold. Molten metal is then poured into the ceramic mold through the pour spout, and the required parts are made after cooling.

Alloys that can be produced by investment casting include carbon steel, alloy steel, heat-resistant alloys, stainless steel, precision alloys, permanent magnet alloys, bearing alloys, copper alloys, aluminum alloys, titanium alloys, and ductile iron. Investment castings are generally more complex in shape and can be produced using various techniques such as silica sol casting, squeeze die casting, and steel silica sol casting. The minimum hole diameter that can be cast on a casting is 0.5 mm, and the minimum wall thickness of a casting is 0.3 mm. During production, some components that were originally composed of several parts can be made into integral parts directly by changing the structure of the parts through investment casting, in order to save processing time and reduce the consumption of metal materials, making the part structure more reasonable.

Understanding investment casting for precision castings

Investment casting, including vacuum die casting process, for precision castings: When using wax materials to make models, investment casting is also known as "lost wax casting." Investment casting usually refers to the process of making a mold in a fusible material, coating the surface of the model with several layers of refractory material to make a mold shell, and then melting and discharging the model in order to obtain a casting without parting surfaces, and filling the mold with sand for casting after high temperature firing. Since wax-based materials are widely used in making models, investment casting, including squeeze die casting, is often referred to as lost wax casting. The lost wax method is to use wax to make a mold of the desired object, and then coat it with mud on the wax tree. After the mud mold is dried, it is fired into a ceramic mold. Once fired, the wax tree is completely melted and lost, leaving only the ceramic mold. The pour spout is usually left from the original ceramic mold, and molten metal is poured into the mold through the pour spout. After cooling, the desired object is made. Investment casting can produce a wide range of alloys, including carbon steel, alloy steel, heat-resistant alloys, stainless steel, precision alloys, permanent magnet alloys, bearing alloys, copper alloys, aluminum alloys, titanium alloys, and ductile iron. Investment castings are generally more complex in shape, with a minimum hole diameter of 0.5 mm and a minimum wall thickness of 0.3 mm. During production, some components that were originally composed of several parts can be made into integral parts directly by changing the structure of the parts through investment casting, in order to save processing time and reduce the consumption of metal materials, making the part structure more reasonable.

The alloys that can be produced by investment casting for precision castings include carbon steel, alloy steel, heat-resistant alloys, stainless steel (including China stainless steel casting), precision alloys, permanent magnet alloys, bearing alloys, copper alloys, aluminum alloys, titanium alloys, and ductile iron. The manufacturing process for investment casting includes the preparation of model materials (usually wax, natural resins, and plastics (synthetic resins)), the preparation and recycling of model materials, and the manufacture of investment and mold modules.

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