Brake disk and method for the production thereof

Abstract

The invention relates to a brake disk having axial friction surfaces, preferably for land vehicles, in particular, an internally ventilated brake disk having two friction rings that are joined via connecting elements, whereby one of the axial outer surfaces of the brake disk is provided with a metallic non-ceramic coating. The injection molded coating is preferably formed during a flame spraying, arc spraying or plasma spraying coating method.

What is claimed is:  
     
         1 . A brake disk, comprising: 
 axial friction surfaces; and    a metallic, non-ceramic coating provided on at least one of said axial friction surfaces of the brake disk.    
     
     
         2 . The brake disk according to  claim 1 , further comprising: 
 a disk-shaped core made of a cast iron material having the axial friction surfaces, wherein the metallic, non-ceramic coating is one of a metallic injection-molded coating and an explosion coating provided on at least one of the axial friction surfaces.    
     
     
         3 . The brake disk according to  claim 2 , wherein the injection-molded coating is one of a flame, arc and plasma injection-molded coating.  
     
     
         4 . The brake disk according to  claim 2 , wherein the injection-molded coating is formed of a harder metal than the disk-shaped core.  
     
     
         5 . The brake disk according to  claim 2 , wherein the injection-molded coating is more oxidation-resistant and wear-resistant than the disk-shaped core.  
     
     
         6 . The brake disk according to  claim 1 , wherein the metallic, non-ceramic coating is an unalloyed or alloyed steel.  
     
     
         7 . The brake disk according to  claim 2 , wherein the metallic, non-ceramic coating is an unalloyed or alloyed steel.  
     
     
         8 . The brake disk according to  claim 1 , wherein the non-ceramic coating is a Cr-containing steel alloy.  
     
     
         9 . The brake disk according to  claim 2 , wherein the non-ceramic coating is a Cr-containing steel alloy.  
     
     
         10 . The brake disk according to  claim 1 , wherein the coating has a Cr content of between 10 to 20%.  
     
     
         11 . The brake disk according to  claim 1 , wherein the coating has a Cr content of between 13 to 19%.  
     
     
         12 . The brake disk according to  claim 10 , wherein the coating has a Cr content of between 13 to 19%.  
     
     
         13 . The brake disk according to  claim 1 , wherein the coating has a Cr content of between 15 to 17%.  
     
     
         14 . The brake disk according to  claim 10 , wherein the coating has a Cr content of between 15 to 17%.  
     
     
         15 . The brake disk according to  claim 1 , wherein the coating has a Cr content of 16%.  
     
     
         16 . The brake disk according to  claim 10 , wherein the coating has a Cr content of 16%.  
     
     
         17 . The brake disk according to  claim 6 , wherein the alloyed steel forming the coating contains the additions of: 
 16% Cr,    0.44% Ni,    0.43% Mn,    1.01% Mo, and    0.36% C.    
     
     
         18 . The brake disk according to  claim 2 , wherein the core consists of a gray cast iron.  
     
     
         19 . The brake disk according to  claim 18 , wherein the gray cast iron forming the core is a high-carbon gray cast iron, which has a carbon content of from 3.7 to 4.0%.  
     
     
         20 . The brake disk according to  claim 18 , wherein the gray cast iron forming the core contains Mo and/or Cr.  
     
     
         21 . The brake disk according to  claim 19 , wherein the gray cast iron forming the core contains Mo and/or Cr.  
     
     
         22 . The brake disk according to  claim 20 , wherein the Mo content of the core is 0.6-0.8% and the Cr content is less than 0.5%.  
     
     
         23 . The brake disk according to  claim 21 , wherein the Mo content of the core is 0.6-0.8% and the Cr content is less than 0.5%.  
     
     
         24 . The brake disk according to  claim 1 , further comprising two friction rings, the friction rings having at least one axial collar on an inner and/or outer circumferential edge, a height of the collar corresponding to an axial dimension of the coating.  
     
     
         25 . The brake disk according to  claim 24 , wherein the coating has an axial dimension of from 0.3 to 1.5 mm.  
     
     
         26 . The brake disk according to  claim 1 , wherein the coating has an axial dimension of from 0.3 to 1.5 mm.  
     
     
         27 . The brake disk according to  claim 24 , wherein the coating has an axial dimension of from 0.5 to 1.2 mm.  
     
     
         28 . The brake disk according to  claim 1 , wherein the coating has an axial dimension of from 0.5 to 1.2 mm.  
     
     
         29 . The brake disk according to  claim 24 , wherein the coating has an axial dimension of from 0.6 to 0.9 mm.  
     
     
         30 . The brake disk according to  claim 1 , wherein the coating has an axial dimension of from 0.6 to 0.9 mm.  
     
     
         31 . The brake disk according to  claim 24 , wherein the coating has an axial dimension of 0.7 mm.  
     
     
         32 . The brake disk according to  claim 1 , wherein the coating has an axial dimension of 0.7 mm.  
     
     
         33 . The brake disk according to  claim 24 , wherein a disk thickness amounts to 38 to 45 mm and an air duct width between the friction rings amounts to 12 mm.  
     
     
         34 . The brake disk according to  claim 1 , wherein a ratio between a disk thickness D1 and an air duct width D meets a condition 3.2<=D1/D2<=4.  
     
     
         35 . The brake disk according to  claim 2 , further comprising: 
 reciprocally engaging contours formed in a transition area between the core and the injection-molded coating.    
     
     
         36 . The brake disk according to  claim 35 , wherein said engaging contours are one of grooves and knob structures.  
     
     
         37 . The brake disk according to  claim 1 , wherein chrome carbides are formed in the coating.  
     
     
         38 . The brake disk according to  claim 37 , wherein a porosity of the coating amounts to less than 5%.  
     
     
         39 . The brake disk according to  claim 1 , wherein a hardness of the coating amounts to from 350 to 500 HV1.  
     
     
         40 . The brake disk according to  claim 38 , wherein a hardness of the coating amounts to from 350 to 500 HV1.  
     
     
         41 . The brake disk according to  claim 1 , wherein carbides and oxides are present in the coating in a finely distributed manner.  
     
     
         42 . The brake disk according to  claim 41 , wherein the carbides and oxides are constructed in the brake coating such that at least 5% of the surface of a micrograph, but preferably 10 to 20% of the surface, appear in an etched micrograph on a cross-section through the coating as a result of the presence of finely distributed carbides and oxides as light spots.  
     
     
         43 . A method of producing a brake disk having axial friction surfaces, the method comprising the acts of: 
 forming a brake disk body of a cast iron material; and    providing a metallic, non-ceramic coating at least in sections and at least on one of the axial friction surfaces.    
     
     
         44 . The method according to  claim 43 , wherein the act of providing the metallic, non-ceramic coating further comprises the act of applying via one of flame, arc and plasma coating methods and injection-molded coating.  
     
     
         45 . The method according to  claim 43 , wherein the act of providing the metallic, non-ceramic coating further comprises the act of using an explosion coating process to apply an injection-molded coating.  
     
     
         46 . The method according to  claim 43 , further comprising the acts of: 
 pretreating an unfinished cast iron brake disk body with a cutting process;    cleaning the brake disk body from machining residues;    roughening a surface and/or eliminating oxidation layers of the brake disk by particle blasting; and    after coating the axial friction surfaces, performing at least one of finished machining and precision-turning of the axial friction surfaces for smoothing said surfaces.    
     
     
         47 . Brake disk for land vehicles having axial friction surfaces, comprising: 
 an internally ventilated brake disk having two friction rings connected by way of webs, the brake disk having a disk-type core made of a cast iron material which is provided on at least one of its axial friction surfaces with a coating;    wherein the coating is a metallic non-ceramic injection molded coating or an explosion coating, which consists of a harder metal than the core, carbides and oxides being present in the coating, such that in the brake coating at least five percent of a surface of a micrograph appear in an etched micrograph on a cross-section through the coating as a result of finely distributed carbides and oxides present as light spots.