Load-adaptive nanocrystalline carbon/amorphous diamond-like carbon composite and preparation method

Abstract

Nanocrystalline carbide/diamond-like carbon composite films and synthesis method near room temperature are described wherein combined magnetron sputtering and pulsed laser ablation produce plasma fluxes intersecting on a substrate surface to form metal carbide and diamond-like carbon composite films of about 10 to 50 nm carbide crystallites encapsulated in a sp3 bonded amorphous diamond-like carbon matrix having a hardness of about 32 GPa and high plasticity, high toughness in contact loading and low friction coefficient.

We claim: 
     
       1. A magnetron assisted laser deposition system for producing metal carbide and diamond-like carbon composite films, comprising: (a) a vacuum chamber and vacuum pump operatively connected to said vacuum chamber for selectively evacuating said vacuum chamber;   (b) a substrate disposed within said vacuum chamber;   (c) a gas inlet defined in a wall of said vacuum chamber and a source of inert gas operatively connected to said gas inlet for selectively inserting said inert gas into said vacuum chamber;   (d) a magnetron sputtering source for generating within said vacuum chamber a flux of metal atoms directed toward said substrate;   (e) a carbon graphite target disposed within said vacuum chamber;   (f) a laser generator and optical means for directing a laser beam onto said carbon graphite target for generating a flux of carbon atoms directed toward said substrate;   (g) wherein said flux of metal atoms intersects said flux of carbon atoms near the surface of said substrate to form on said substrate a composite film of metal carbide in a diamond-like carbon matrix.   
     
     
       2. The system of claim 1 wherein said metal is selected from the group consisting of titanium, tungsten, silicon, vanadium, tantalum, zirconium, hafnium, chromium, molybdenum, niobium, copper and aluminum. 
     
     
       3. The system of claim 1 wherein said source of inert gas comprises argon. 
     
     
       4. The system of claim 1 wherein said substrate comprises a stainless steel. 
     
     
       5. The system of claim 1 further comprising means for rotating said substrate and means for rotating said carbon graphite target. 
     
     
       6. The system of claim 1 wherein said laser source is an excimer pulsed laser generator. 
     
     
       7. A method for producing a metal carbide and diamond-like carbon composite film, comprising the steps of: (a) providing a vacuum chamber and vacuum pump operatively connected to said vacuum chamber for selectively evacuating said vacuum chamber, said vacuum chamber having a gas inlet defined in a wall of said vacuum chamber and a source of inert gas operatively connected to said gas inlet for selectively inserting said inert gas into said vacuum chamber;   (b) disposing within said vacuum chamber a substrate and a carbon graphite target;   (c) providing a means for generating a flux of metal atoms within said vacuum chamber and generating a flux of metal atoms directed toward said substrate;   (d) directing a laser beam onto said carbon graphite target to generate a flux of carbon atoms directed toward said substrate;   (e) wherein said flux of metal atoms intersects said flux of carbon atoms near the surface of said substrate to form on said substrate a composite film of metal carbide in a diamond-like carbon matrix.   
     
     
       8. The method of claim 7 wherein said metal is selected from the group consisting of titanium, tungsten, silicon, vanadium, tantalum, zirconium, hafnium, chromium, molybdenum, niobium, copper and aluminum. 
     
     
       9. The method of claim 7 wherein said source of inert gas comprises argon. 
     
     
       10. The method of claim 7 wherein said substrate comprises a stainless steel. 
     
     
       11. The method of claim 7 further comprising the steps of rotating said substrate and rotating said carbon graphite target. 
     
     
       12. The method of claim 7 wherein said composite film is formed on said substrate at about room temperature. 
     
     
       13. The method of claim 7 wherein said step of generating a flux of metal atoms is performed utilizing a magnetron sputtering source. 
     
     
       14. The method of claim 7 wherein said step of generating a flux of carbon atoms is performed utilizing an excimer pulsed laser generator. 
     
     
       15. A nanocrystalline metal carbide and diamond-like carbon composite film containing about 10 to 50 nm metal carbide crystallites encapsulated in an amorphous diamond-like carbon matrix of about 30 volume percent fraction and fabricated according to the method of claim 7. 
     
     
       16. The composite film of claim 15 wherein said metal is selected from the group consisting of titanium, tungsten, silicon, vanadium, tantalum, zirconium, hafnium, chromium, molybdenum, niobium, copper and aluminum.