Surface treatment method

Abstract

A surface treatment method is disclosed. The surface treatment method forms a matte nickel plating layer on a substrate, followed by the brushed finishing and degreasing processes. The degreasing processes includes ultrasonic degreasing and electrolytic degreasing. Next, an acid activation is performed before the formation of a non-leveling nickel plating layer. Finally, a chromium plating layer and a PVD chromium film are sequentially formed. The present invention provides a high quality metal appearance and enhanced corrosion resistance with reduced cost.

What is claimed is: 
     
         1 . A surface treatment method comprising:
 forming a matte nickel plating layer on a substrate;   performing a brushed finishing to the matte nickel plating layer to form a brushed surface on the substrate;   performing an ultrasonic degreasing to the brushed surface to form an ultrasonically degreased surface;   performing an electrolytic degreasing to the ultrasonically degreased surface to form an electrolytically degreased surface;   performing an acid activation to the electrolytically degreased surface to form an acid-activated surface;   forming a non-leveling nickel plating layer on the acid-activated surface;   forming a chromium plating layer on the non-leveling nickel plating layer; and   forming a chromium film on the chromium plating layer by physical vapor deposition.   
     
     
         2 . The surface treatment method as claimed in  claim 1 , wherein the substrate is made of a plastic or a metal. 
     
     
         3 . The surface treatment method according to  claim 2 , wherein the plastic is acrylonitrile butadiene styrene (ABS) resin. 
     
     
         4 . The surface treatment method according to  claim 2 , wherein the metal is copper, nickel, chromium, titanium, or zirconium. 
     
     
         5 . The surface treatment method according to  claim 1 , wherein the ultrasonic degreasing uses an oil removal powder. 
     
     
         6 . The surface treatment method according to  claim 5 , wherein the oil removal powder contains sodium hydroxide. 
     
     
         7 . The surface treatment method according to  claim 1 , wherein the ultrasonic degreasing is performed at a temperature of 45-55° C. 
     
     
         8 . The surface treatment method according to  claim 1 , wherein the electrolytic degreasing uses an electrolytic degreasing powder. 
     
     
         9 . The surface treatment method according to  claim 8 , wherein the electrolytic degreasing powder contains sodium hydroxide. 
     
     
         10 . The surface treatment method according to  claim 1 , wherein the electrolytic degreasing is performed at a temperature of 45-55° C. 
     
     
         11 . The surface treatment method according to  claim 1 , wherein the acid activation is performed by immersing the substrate in an acid solution. 
     
     
         12 . The surface treatment method according to  claim 11 , wherein the acid solution is comprised of activated acid salt and water. 
     
     
         13 . The surface treatment method according to  claim 1 , wherein the non-leveling nickel plating layer is formed by using the Watts nickel bath.