Nowadays, techniques for the construction of concrete tools exist, as for instance in U.S. Pat. No. 4,588,443. However, these methods cannot be applied to sheet drawing or other highly demanded applications as the mechanical resistance is lacking, because the resistance of the used concretes or metal layers in the working zones is too low. There are also techniques to obtain reinforced polymeric concretes of high resistance (GB2250703A), reinforced concretes with fibres for the construction of injection moulds (JP2003170410) or the application of reinforced highly resistant polymers (WO 03/039779 A1). However, in all these cases the possibility of using these techniques for shaping high quality sheets and other metal to metal contact applications is very small. The elements which are used to reinforce the concrete or polymer scratch the drawn sheet, and the superficial micro-defects permit the deposit of sheet particles which in turn produce adherences in sheets which will be drawn afterwards. In order to avoid this effect, some techniques were developed by surface melting of a metallic layer (DE69908273T2) or by employing a layer which can be used as mould for the concrete mix (JP2002346663, DE202006010493U1).
In both cases, the quality of the union metal-concrete is only satisfactory for few applications.
The use of concrete as support element and not as principal resistant element (as it is the case in the present invention) in the produced pieces by thermal projection of metals is known. Normally, these techniques in which the concrete is used as support element, the concrete is cast in the metallic piece once it is obtained by thermal projection on another model (JP63309332, U.S. Pat. No. 3,631,745, JP2104424, JP2251323).
Realising thermal projection on concrete when the concrete is the resistant element is also known in protecting concrete against corrosion or against fire as it is described in U.S. Pat. No. 6,224,943, EP0669299 A2, and U.S. Pat. No. 5,879,817. Thermal projection on low resistance resins is also known in the production of low cost models where the mechanical requirements are low (JP60108122).
There are many techniques for inserting layers by thermal projection which are wear or corrosion resistant in comparison to the metallic substrates, in particular, ceramics and hard metals (JP2004175112).