Description of investment casting

Investment casting is also called the "lost wax casting", usually in the wax models surface coated with several layers of refractory material, wait for after its hardened and dry, the wax models of fuse to type, made of shell, again after roasting, then pouring, a method for casting, because of the size of the castings with high precision and surface finish, so it is also called "revestment precision casting"

The types of alloys that can be produced by investment casting are carbon steel, alloy steel, heat-resistant alloy, stainless steel, precision alloy, permanent magnet alloy, bearing alloy, copper alloy, aluminum alloy, titanium alloy and ductile iron, etc.

The shape of investment castings is generally complex. The minimum diameter of the hole that can be cast in the casting is up to 0.5mm, and the minimum wall thickness of the casting is 0.3mm. In the production of some original parts from a combination of parts, by changing the structure of the parts, design into a whole part and directly from investment casting, in order to save the processing time and metal material consumption, make the parts structure more reasonable.


The weight of investment castings is mostly tens of zero (i.e. dozens of grams to several kilograms). It is more difficult to produce heavy castings by investment casting method, but the weight of large investment castings has reached about 800 cows.

The process of investment casting is complicated, difficult to control, and the materials used and consumed are expensive. Therefore, it is suitable for the production of small parts with complex shape, high precision requirements, or difficult to carry out other processing, such as turbine engine blades.

Manufacturing of investment mold

The first process of investment casting production is investment mold manufacturing. Investment mold is used to form the model of the cavity in the refractory shell. Therefore, to obtain the casting with high dimensional accuracy and surface finish, the investment mold itself should have high dimensional accuracy and surface finish. In addition, the performance of the investment mold itself should be as easy as possible to make the subsequent shell and other procedures. In order to obtain the high quality investment mold, in addition to good pressing (pressing investment mold die), it is necessary to select appropriate mold material (die material) and reasonable mold making process.