Apparatus and method for generating a layer system

Abstract

For improving the variability in the coating of substrates a coating apparatus is proposed having a plasma generator for generating a plasma jet which exits from a coating head of the plasma generator. A first particle reservoir and a second particle reservoir are provided. The particles from the first particle reservoir and the second particle reservoir are supplied to the plasma jet as a particle mixture via a transport pipe. A supply control device is provided for setting the amount of particles from the first particle reservoir fed into the transport pipe relative to the amount of particles from the second particle reservoir.

What is claimed is: 
     
         1 . A coating apparatus for coating a substrate, comprising:
 a plasma generator for generating a plasma jet; which exits from   a coating head of the plasma generator from which the plasma jet exits;   a first particle reservoir connected with a transport pipe for supplying particles stored in the first particle reservoir to the plasma jet:   at least a second particle reservoir is provided and configured to supply particles from the second reservoir via the transport pipe to the plasma jet in a particle mixture with the particles from the first particle reservoir; and   a supply control device for setting an amount of the particles fed from the first particle reservoir into the transport pipe relative to the amount of the particles fed from the second particle reservoir into the transport pipe.   
     
     
         2 . Coating apparatus according to  claim 1 , wherein the supply control device is configured in such a way that a composition of a particle mixture is changeable in a time-dependent manner. 
     
     
         3 . Coating apparatus of  claim 2 , wherein a controller is provided for controlling the amount of particle mixture supplied to the plasma jet. 
     
     
         4 . Coating apparatus of  claim 3 , wherein the controller is a switch for allowing and/or interrupting the supply of the particle mixture to the plasma jet. 
     
     
         5 . Coating apparatus of  claim 1  wherein a plurality of particle reservoirs is provided. 
     
     
         6 . Coating apparatus of  claim 1 , wherein at least one separate process gas is provided to be mixed with the particles from one of the particle reservoirs in order to form a fluidized powder. 
     
     
         7 . Coating apparatus of  claim 6 , wherein a separate process gas is provided for each particle reservoir. 
     
     
         8 . Coating apparatus of  claim 6 , wherein the particle reservoir and the corresponding process gas form a particle supply unit, the particle supply unit having a process gas control unit for controlling a mixing relation between particles and process gas. 
     
     
         9 . Coating apparatus of  claim 1 , wherein the coating apparatus has at least a second coating head and at least a further particle supply unit corresponding to the second coating head, the further particle supply unit having a particle reservoir, a corresponding process gas and a process gas control unit. 
     
     
         10 . Coating apparatus of  claim 9 , wherein the coating apparatus has a plurality of coating heads and corresponding particle supply units. 
     
     
         11 . Method for coating a substrate comprising the following steps:
 generating a plasma jet with a plasma generator having at least one coating head from the plasma jet exits;   feeding particles from at least a first particle reservoir and from at least a second particle reservoir via a transport pipe to a supply control device in which they are mixed;   supplying a particle mixture of particles from the first particle reservoir and of particles from the second particle reservoir from the supply control device to the plasma jet via the transport pipe; and   directing the plasma jet together with the particle mixture onto a surface of the substrate in order to form the coating.   
     
     
         12 . Method for coating a substrate according to  claim 11 , wherein the particles from the first particle reservoir are fluidized with a first process gas and the particles from the second particle reservoir are fluidized with a second process gas. 
     
     
         13 . Method for coating a substrate according to  claim 11 , wherein the fraction of particles from the first particle reservoir in the particle mixture is set between 10% and 90%, and the fraction of particles from the second particle reservoir in the particle mixture is set between 10% and 90%. 
     
     
         14 . Method for coating a substrate according to  claim 11 , wherein the ratio between particles from the first particle reservoir and particles from the second particle reservoir is changed during the coating of the substrate. 
     
     
         15 . Method for coating a substrate comprising the following steps:
 generating a plasma jet with a plasma generator of a coating apparatus, the plasma jet exiting from a coating head;   supplying particles from a first particle reservoir a transport pipe to the plasma jet at a first supply location; and   supplying particles from a second particle reservoir to the plasma jet at a second supply location, wherein the position of the first supply location and the position of the second supply location relative to the plasma jet are chosen in such a way that on the substrate a first layer with particles from the first particle reservoir and a second layer with particles from the second particle reservoir or a gradient layer or a compound layer is formed.   
     
     
         16 . Method for coating a substrate according to  claim 15 , wherein the second layer or the gradient layer or the compound layer is covered with a further layer, wherein particles from a third particle reservoir are fed into a second transport pipe, supplied to a second plasma jet of a second coating head, and applied onto the second layer of particles from the second particle reservoir or onto the gradient layer or onto the compound layer. 
     
     
         17 . A coating apparatus for coating a substrate, comprising:
 at least a first plasma generator and at least a second plasma generator each of which generating a plasma jet;   a coating head of the first plasma generator from which the plasma jet exits and a coating head of the second plasma generator from which the plasma jet exits;   a first particle reservoir connected with a transport pipe for supplying particles stored in the first particle reservoir to the plasma jet of the first plasma generator;   at least a second particle reservoir for supplying particles from the second reservoir via the transport pipe to the plasma jet of the first plasma generator in a particle mixture with the particles from the first particle reservoir;   at least a third particle reservoir connected with a transport pipe for supplying particles stored in the third particle reservoir to the plasma jet of the second plasma generator;   a supply control device for setting an amount of the particles fed from the first particle reservoir into the transport pipe to a first injector relative to the amount of the particles fed from the second particle reservoir into the transport pipe to a second injector, wherein the first injector and the second injector are arranged in relation to the plasma jet of the first plasma generator; and   a further supply control device for setting an amount of the particles fed from the third particle reservoir into the transport pipe to a third injector arranged in relation to the plasma jet of the second plasma generator.