Composite Casting

Requirement

High cost materials on less expensive substrates

A composite casting is created when it is composed of two different castable materials from our production programme and arranged as outer and inner layer ( or inner coating).

Alternative production processes to achieve this affect are for example the welding resurfacing process on a roller body, pressing two cylinders into one another, or various coating techniques.

A great advantage of composite casting is the freedom of choice of the layer thicknesses, which can start from a minimum of 5mm and be as thick as 150mm.

During the casting process, the two materials are poured into the mould one after the other. Here, time and temperature must be strictly controlled to match the appropriate material characteristics and the solidification properties.

After the outer layer has already solidified except for a thin inner layer of approx 3 to 8mm wall thickness, the inner layer is cast at a precisely defined time and at the correct temperature. It will mix with the residual melt of the outer layer and continually solidify from the outside towards the inside.

Here, there are limitations with regard to the material combinations possible, since tensions created by differing solidification characteristics or changes in the two materials may be too great and lead to the formation of cracks.

Numerous applications have already been realised, for example for the sure application of hard wear layers on the outside or inside. The application of expensive materials such as nickel-based alloys on less expensive substrates, both inside and outside.

In the case of thick applied layers, it is thus an economical procedure, offering a very great degree of certainty with great flexibility as to layer thicknesses and the materials that can be used.