Introduction to investment casting manufacturing

When making a pattern with wax, die forging is also known as "lost wax forging".Melt forging generally refers to the forging plan that the fusible material is made into shape, how many layers of refractory material are covered in the shape profile to make the shell, and then the shape is melted and squeezed out of the shell, so as to obtain the casting shape without parting surface, which can be filled with sand after being roasted at high temperature.Because the appearance generally adopts wax material to manufacture, it is often called "lost wax forging".

The alloy varieties produced by the fusible die forging method include carbon steel, alloy steel, heat-resisting alloy, stainless steel, compact alloy, permanent magnet alloy, bearing alloy, copper alloy, aluminum alloy, titanium alloy and nodular cast iron.

The shape of the investment casting is relatively large, the minimum diameter of the hole on the casting can be up to 0.5mm, and the minimum wall thickness of the casting is 0.3mm.In the production can be some originally by a few parts combination and become the parts, through the process of changing the layout of the parts, imagine to become the group parts and indirectly by the die forging casting, to throttle processing hours and metal material consumption, make the parts layout more reasonable.

 The weight of the investment casting is mostly dozens of tenths of an ox (from a few grams to a dozen kilograms, generally not over 25 kilograms).

The process of melt die forging is huge, and it is not easy to control, and the materials used and consumed are expensive, so it can be used to produce small parts with large shape, high precision requirements, or difficult to stop other processing, such as turbine engine blades.

Higher dimensional precision investment castings, the regular of CT4-6 (sand mould forging is CT10 ~ 13, die-casting is CT5 ~ 7), is because the process of liquid die forging technology of large, affect the casting dimension accuracy of identity is more, shorten the pattern material (for example, the deformation of the casting, shell in the process of heating and cooling line qualitative change, alloy reduced rates and the deformation of the solidification process of castings, etc., to is popular the investment castings dimension precision is high, but its divisive still needs improvement (take, high temperature of the wax casting size differences in sex is much progress).

When suppressing the molten mould, the pressing mould with high lumen general brightness is adopted, so the general lumen general brightness of the molten mould is also higher than the force.In addition, the shell of engineering vehicle spare parts by high temperature resistant special binder and refractory materials prepared by the refractory coating hanging on the molten mold and made of indirect battle with the molten metal cavity general situation of high brightness.As a result, the general brightness of the investment casting is higher than that of the ordinary casting, which can reach Ra.

Die forging made the greatest strengths is because of molten casting have high dimensional accuracy and general situation of brightness, Marine spare parts to be cut machine, just leave a small amount of processing on higher requirements on the parts parts allowance can be, and even some castings only grinding, polishing, it is not necessary to machine can use.It can be seen that a large number of machine tools and machining hours can be throttled by the forging method of melt die, which can greatly save the raw material of metal.

Another advantage of the die forging method is that it can cast large castings of various alloys, especially superalloy castings.For example, the blade of a jet engine, its streamlined outline and cooling cavity are almost impossible to form by machine processing.It can not only achieve mass production, but also guarantee the divergence of the casting and prevent the stress concentration of the residual blade after machining.