Method For Producing A Hollow Body By Cold Spraying And Mould Core Suitable For Carrying Out Said Method

Abstract

A method is disclosed for producing a hollow body by cold spraying. A mold core is used for producing the hollow body, the mold core being prepared for the production of the hollow body by cold spraying in a suitable manner by means of an auxiliary layer. The auxiliary layer may include or consist of a metallic material and therefore forms a suitable surface to which the particles processed by cold spraying remain adhered to form the hollow body. The mold core can therefore be produced from an inexpensive material such as sand or wood, although said materials are in principle have limited suitability for depositing metals by cold spraying. The auxiliary layer can be applied to the mold core as a foil, or be produced on the mold core by cold-spraying low-melting and/or soft materials, for example.

What is claimed is: 
     
         1 . A method comprising, in the following order:
 forming a starting coat on a mold core, wherein the auxiliary layer is metallic or contains predominantly metallic components,   coating the mold core using a cold spraying process to produce a hollow body,   removing the mold core from the hollow body, and   removing the starting coat from the hollow body.   
     
     
         2 . The method of  claim 1 , wherein the starting coat has a different material composition than the hollow body. 
     
     
         3 . The method of  claim 1 , wherein the starting coat comprises an aluminum foil. 
     
     
         4 . The method of  claim 3 , comprising adhesively bonding the aluminum foil onto the mold core. 
     
     
         5 . The method of  claim 1 , wherein the starting coat is formed on the mold core by low-pressure gas dynamic spraying of a metallic material. 
     
     
         6 . The method of  claim 5 , wherein the metallic material comprises one or more of zinc, tin, lead, aluminum, copper, silver, or gold, or an alloy of zinc, tin, lead, aluminum, copper, silver, or gold. 
     
     
         7 . The method of  claim 6 , wherein the starting coat has a multilayer design including multiple auxiliary layers, wherein forming the starting coat comprises forming multiple auxiliary layers of increasingly harder and/or higher-melting metallic materials. 
     
     
         8 . The method of  claim 7 , wherein the starting coat is produced by forming two auxiliary layers comprising:
 a base layer lying on the mold core and composed of zinc, tin or lead, or a metal alloy based on zinc, tin, or lead, and   a top layer formed over the base layer and composed of zinc, aluminum, copper, silver, or gold, or a metal alloy based on zinc, aluminum, copper, silver, or gold.   
     
     
         9 . The method of  claim 1 , wherein the mold core is produced from wood, plastic, metal, or bonded sand. 
     
     
         10 . A mold core, comprising:
 a surface suitable as a substrate for cold spraying,   wherein the surface is formed by at least one auxiliary layer composed of a metallic material, which forms a starting coat on the mold core.   
     
     
         11 . The mold core of  claim 10 , wherein said mold core consists of bonded sand, wood, metal, or plastic.