Highly durable and abrasion resistant composite diamond-like carbon decorative coatings with controllable color for metal substrates

Abstract

The invention provides a highly durable and abrasion-resistant composite diamond-like carbon coating with controllable color which is ideally suitable as a decorative coating on electrically conductive, e.g. metal, substrates, including architectural hardware and fixtures made of brass and other metals, jewelry, medical and dental instruments, writing instruments such as pens and pencils, musical instruments, eyeglass frames, cigar and cigarette lighters, automobile hood ornaments and other components, sporting equipment and other products for leisure activities such as golf club shafts, golf club heads, cycling equipment, and fishing and hunting equipment, and other similar electrically conductive substrates. The invention also provides the process for depositing a highly adherent, highly abrasion resistant composite diamond-like carbon coating to metal substrates. The invention also provides the process for depositing a highly adherent, highly abrasion resistant composite diamond-like carbon coating to electrically conductive substrates. The composite diamond-like carbon coating structure consists of at least a first layer of Si-DLC which comprises the elements C, H, Si and possibly O and N. An additional coating containing layers of Si-DLC and DLC may be applied over top of the first Si-DLC layer. The optional additional layers of Si-DLC are also containing the elements C, H, Si and possibly O and N. The optional additional layers of DLC contain the elements C, H and possibly N. The decorative and abrasion-resistant composite diamond-like carbon coating is deposited by ion-assisted plasma deposition from carbon-containing and silicon-containing precursor gases consisting of hydrocarbon, silane, organosilane, organosilazane and organo-oxysilicon compounds, or mixtures thereof, and has the properties of Nanoindentation hardness in the range of approximately 5 to 35 GPa, modulus in the range of approximately 50 GPa to 300 GPa, thickness in the range of approximately 1 to 25 micrometers, and colors which can be varied continuously along the spectrum of: light yellow to bronze to copper-gold to burgundy to bluish-black to black, exhibiting reflected light chromaticity coordinate values (Y, x, y) values for Y of approximately 5 to 50, x of approximately 0.25 to 0.50, and for y of approximately 0.25 to 0.45. The elemental composition, refractive index and thickness of the composite diamond-like carbon coating are chosen to produce the desired reflected optical color. The deposition process parameters such as precursor gas composition, plasma power, pressure, and substrate bias voltage are adjusted to produce coatings with different elemental composition and refractive indexes, which change the reflected optical color, and hardness and elastic modulus, which effect the abrasion resistance and durability of the coating.

What is claimed is:  
     
         1 . An abrasion-resistant coated product comprising an electrically conductive substrate coated on at least one surface with a composite diamond-like carbon decorative coating, said decorative coating comprising at least a first layer of Si-doped diamond-like carbon containing the elements C, H and Si, using ion-assisted plasma deposition and using carbon-containing and silicon-containing precursor gases selected from the group consisting of hydrocarbon, silane, organosilane, organosilazane and organo-oxysilicon compounds, and mixtures thereof, the resulting abrasion-resistant decorative coating having the properties of a Nanoindentation hardness in the range of about 5 to about 35 GPa and a thickness in the range of about 1 to about 25 micrometers.  
     
     
         2 . The product of  claim 1  wherein said color exhibits reflected light chromaticity coordinate values (x,y) values for x of about 0.25 to about 0.50, and for y of about 0.25 to about 0.45, as measured with CIE 1931 source C standard illuminant and CIE 1931 2-degree standard observer.  
     
     
         3 . The product of  claim 2  wherein the color of said decorative coating is selected from the group consisting of light yellow, bronze, copper-gold, burgundy, bluish-black, and black.  
     
     
         4 . The product of  claim 1  wherein said decorative coating also contains the elements selected from the group of N and O.  
     
     
         5 . The product of  claim 1  wherein said decorative coating comprises at least a second layer of diamond-like carbon containing the elements C and H deposited using ion-assisted plasma deposition using a hydrocarbon gas.  
     
     
         6 . The product of  claim 5  wherein said second layer also contains the element N.  
     
     
         7 . The product of  claim 1  wherein said substrate is the shaft of a golf club.  
     
     
         8 . The product of  claim 1  wherein said substrate the head of a golf club.  
     
     
         9 . The product of  claim 8  wherein said golf club is a putter.  
     
     
         10 . The product of  claim 8  wherein said golf club is a driver.  
     
     
         11 . The product of  claim 8  wherein said golf club is a wedge.  
     
     
         12 . The product of  claim 8  wherein said golf club is an iron.  
     
     
         13 . An abrasion-resistant coated product comprising the shaft of a golf club coated on at least a portion of the outer surface with a composite diamond-like carbon decorative coating, said decorative coating comprising at least one layer of Si-doped diamond-like carbon containing the elements C, H and Si, using ion-assisted plasma deposition and having the properties of Nanoindentation hardness in the range of about 5 to about 35 GPa and thickness in the range of about 1 to about 25 micrometers.  
     
     
         14 . The product of  claim 13  wherein the color of said decorative coating is black.  
     
     
         15 . An abrasion-resistant coated product comprising the head of a golf club coated on at least a portion of the outer surface with a composite diamond-like carbon decorative coating, said decorative coating comprising at least one layer of Si-doped diamond-like carbon containing the elements C, H and Si, using ion-assisted plasma deposition and having the properties of Nanoindentation hardness in the range of about 5 to about 35 GPa, modulus in the range of approximately 50 GPa to approximately 300 GPa, and thickness in the range of about 1 to about 25 micrometers.  
     
     
         16 . The product of  claim 15  wherein the color of said decorative coating is black.  
     
     
         17 . The product of  claim 15  wherein said golf club is a putter.  
     
     
         18 . The product of  claim 15  wherein said golf club is a driver.  
     
     
         19 . The product of  claim 15  wherein said golf club is a wedge.  
     
     
         20 . The product of  claim 15  wherein said golf club is an iron.  
     
     
         21 . The product of  claim 1  wherein said substrate is selected from the group consisting of brass hardware, brass fixtures, jewelry, medical instruments, dental instruments, writing instruments, musical instruments, eyeglass frames, cigar lighters, cigarette lighters, automobile ornaments, cycling equipment, fishing equipment and hunting equipment.  
     
     
         22 . The product of  claim 1  wherein said hydrocarbon compound is selected from the group consisting of methane, butane, acetylene, cyclohexane and mixtures thereof.  
     
     
         23 . The product of  claim 1  wherein said silane compound is selected from the group consisting of silane, disilane, diethylsilane, tetramethylsilane and mixtures thereof.  
     
     
         24 . The product of  claim 1  wherein said organosilazane compound is selected from the group consisting of hexamethyldisilazane, tetramethyldisilazane and mixtures thereof.  
     
     
         25 . The product of  claim 1  wherein said organo-oxysilicon compound is selected from the group consisting of hexamethyldisiloxane, tetramethyldisiloxane, ethoxytrimethylsilane, octamethycyclotetrasiloxane, and mixtures thereof.  
     
     
         26 . The product of  claim 5  wherein said hydrocarbon is selected from the group consisting of methane, butane, acetylene, cyclohexane and mixtures thereof.  
     
     
         27 . The product of  claim 1  wherein said precursor gases consist of a mixture of tetramethylsilane and cyclohexane.  
     
     
         28 . The product of  claim 1  wherein said precursor gases consist of a mixture of hexamethyldisilazane and cyclohexane.  
     
     
         29 . A method for producing an abrasion resistant decorative coating on at least one surface of an electrically conductive substrate by: 
 ion-assisted plasma depositing from carbon-containing and silicon-containing precursor gases a composite diamond-like carbon decorative coating, said decorative coating comprising at least one layer of Si-doped diamond-like carbon containing the elements C, H and Si;    said precursor gases selected from the group consisting of hydrocarbon, silane, organosilane, organosilazane and organo-oxysilicon compounds, and mixtures thereof;    using a substrate bias voltage in the range of about −100 Volts to about −1000 Volts;    recovering a product coated with said abrasion resistant decorative coating having the properties of a Nanoindentation hardness in the range of about 5 to about 35 GPa and a thickness in the range of about 1 to about 25 micrometers.    
     
     
         30 . The product of  claim 29  wherein said colors exhibit reflected light chromaticity coordinate values (x, y) values for x of about 0.25 to about 0.50, and for y of about 0.25 to about 0.45, as measured with CIE 1931 source C standard illuminant and CIE 1931 2-degree standard observer.  
     
     
         31 . The product of  claim 29  wherein said colors also exhibit reflected light chromaticity values (Y) of about 5 to about 50.  
     
     
         32 . The method of  claim 29  wherein the color of said decorative coating is selected from the group consisting of light yellow, bronze, copper-gold, burgundy, bluish-black, and black.  
     
     
         33 . The method of  claim 29  in wherein the ion-assisted plasma is a capacitively-coupled RF plasma.  
     
     
         34 . The method of  claim 29  wherein the ion-assisted plasma is a DC plasma.  
     
     
         35 . The method of  claim 29  wherein an ion beam source is used to generate the ion-assisted plasma.  
     
     
         36 . A method for producing an abrasion resistant decorative coating on at least one surface of an electrically conductive substrate by ion-assisted sputter depositing a composite diamond-like carbon decorative coating, said decorative coating comprising at least one layer of Si-doped diamond-like carbon containing the elements C, H and Si, said coating having the properties of a Nanoindentation hardness in the range of about 5 to about 35 GPa and a thickness in the range of about 1 to about 25 micrometers.  
     
     
         37 . The product of  claim 36  wherein said colors exhibit reflected light chromaticity coordinate values (x, y) values for x of about 0.25 to about 0.50, and for y of about 0.25 to about 0.45, as measured with CIE 1931 source C standard illuminant and CIE 1931 2-degree standard observer.  
     
     
         38 . The product of  claim 22  wherein said colors also exhibit reflected light chromaticity values (Y) of about 5 to about 50.  
     
     
         39 . The method of  claim 22  wherein the color of said decorative coating is selected from the group consisting of light yellow, bronze, copper-gold, burgundy, bluish-black, and black.