Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Investment casting, also known as lost-wax casting or precision casting, is an industrial manufacturing process used to create high-precision metal parts with complex geometries and excellent surface finishes. It is one of the oldest known metal-forming techniques, dating back thousands of years, but has been modernized for applications in industries like aerospace, automotive, medical devices, and power generation. The term "investment" refers to the process of surrounding (or "investing") a wax pattern with a refractory ceramic material to form a mold.

Key Steps in the Investment Casting Process

1.Wax Pattern Creation: A wax model (or pattern) of the desired part is produced, often by injecting wax into a metal die. Multiple patterns may be attached to a central wax sprue (a wax tree) to create several parts at once.

2.Ceramic Shell Building: The wax assembly is repeatedly dipped into a liquid ceramic slurry (refractory material mixed with binders) and coated with fine sand or stucco. This process is repeated several times (up to 10 layers) to build a strong, thick ceramic shell around the wax. The shell is then allowed to dry and harden.

3.Wax Removal (Dewaxing): The ceramic shell is heated in an autoclave or furnace to melt and drain out the wax, leaving a hollow cavity in the exact shape of the part. This is why it's called "lost-wax" casting—the wax is sacrificed to create the mold.

4.Preheating and Metal Pouring: The empty ceramic mold is preheated to a high temperature (around 1,000°C or more) to prevent thermal shock. Molten metal (such as stainless steel, aluminum, titanium, brass, or other alloys) is then poured into the cavity via gravity, vacuum, or centrifugal force.

5.Cooling and Shell Removal: The mold is allowed to cool, solidifying the metal into the part's shape. The ceramic shell is then broken away (often by vibration or knocking) to reveal the cast part.

6.Finishing: The parts are cut from the sprue, and any excess material (gates or risers) is removed. Additional processes like heat treatment, machining, or surface finishing may be applied for precision.