Method for improving the features of phosphate coating

Abstract

Properties of a phosphate coating are improved by preparing and applying a mixture containing nano-dimensioned hexagonal boron nitride, known as a solid lubricant, to a Zn, Zn-Ca, Fe and Mn phosphate coating. The hexagonal boron nitride is added to the coating bath during the phosphate treatment. Products coated with Zn, Zn-Ca, Fe and Mn phosphate accommodated with hexagonal boron nitride are disclosed.

1 . A method for improving properties of a phosphate coating, the method comprising adding a mixture comprising nano-dimensioned particles of hexagonal boron nitride, known as a solid lubricant, into a phosphate coating bath during a phosphate treatment. 
     
     
         2 . A method for improving properties of a phosphate coating according to  claim 1 , wherein the to mixture is in at least one of two ways; one being water-based containing only 0.2% to 10% hexagonal boron nitride by weight, and one being water-based containing, in addition to the same amount of hexagonal boron nitride, at least one of a nano-dimensioned solid lubricant, a surfactant and a wetter agent, and a phosphate bath chemical. 
     
     
         3 . A method for improving properties of a phosphate coating according to  claim 1 , wherein the mixture is added into the phosphate coating bath after being well-mixed using at least one of mechanical and ultrasonic methods. 
     
     
         4 . A method for improving properties of a phosphate coating according to  claim 1 , wherein the mixture is added into at least of a Zn, Zn-Ca, Fe and Mn phosphate bath at a ratio from 1% to 50% by weight. 
     
     
         5 . A method for improving properties of a phosphate coating according to  claim 1 , wherein a D50 of the grain size of the nano-dimensioned hexagonal boron nitride added into the phosphate coating is less than 500 nanometers. 
     
     
         6 . A method for improving properties of a phosphate coating according to  claim 1 , wherein the method improves lubricant properties of the phosphate coating as a result of placement among phosphate crystals during formation. 
     
     
         7 . A method for improving properties of a phosphate coating according to  claim 1 , wherein the application of the mixture to an Mn phosphate coating will help to decrease the coefficient of friction and increase resistance to abrasion. 
     
     
         8 . A method for improving properties of a phosphate coating according to  claim 1 , wherein at least one of an applied Zn, Zn-Ca, Fe phosphate coating containing the mixture is used as a preliminary preparation in metal forming so as to decrease the coefficient of friction. 
     
     
         9 . A method for improving properties of a phosphate coating according to  claim 1 , wherein at least one of an applied Mn, Zn, Zn-Ca, Fe phosphate coating containing the mixture will be help to decrease the coefficient of friction at all surfaces applied. 
     
     
         10 . A method for improving properties of a phosphate coating according to  claim 2 , wherein the nano-dimensioned solid lubricant comprises at least one of molybdenum disulfide, graphite, and tungsten disulfide. 
     
     
         11 . A method of improving properties of a phosphate coating according to  claim 2 , wherein the surfactant and wetter agent comprises at least one of a non-ionic, anionic, cationic, and amphoteric surfactant and wetter agent. 
     
     
         12 . A method for improving properties of a phosphate coating according to  claim 2 , wherein the phosphate bath chemical comprises at least one of a phosphoric acid solution containing alkali metal/heavy metal ions, orthophosphoric acid, a manganese phosphate salt, an oxidant, a catalyzer, an α-hydroxy acid, EDTA, NTA, DTPA glyconic acids, nickel, and tungstate ions. 
     
     
         13 . A method for improving properties of a phosphate coating according to  claim 2 , wherein the mixture is added into the phosphate coating bath after being well-mixed using at least one of mechanical and ultrasonic methods. 
     
     
         14 . A method for improving properties of a phosphate coating according to  claim 13 , wherein the mixture is added into at least of a Zn, Zn-Ca, Fe and Mn phosphate bath at a ratio from 1% to 50% by weight. 
     
     
         15 . A method for improving properties of a phosphate coating according to  claim 14 , wherein a D50 of the grain size of the nano-dimensioned hexagonal boron nitride added into the phosphate coating is less than 500 nanometers. 
     
     
         16 . A method for improving properties of a phosphate coating according to  claim 15 , wherein the method improves lubricant properties of the phosphate coating as a result of placement among phosphate crystals during formation. 
     
     
         17 . A method for improving properties of a phosphate coating according to  claim 16 , wherein the application of the mixture to an Mn phosphate coating will help to decrease the coefficient of friction and increase resistance to abrasion. 
     
     
         18 . A method for improving properties of a phosphate coating according to  claim 17 , wherein at least one of an applied Zn, Zn-Ca, Fe phosphate coating containing the mixture is used as a preliminary preparation in metal forming so as to decrease the coefficient of friction. 
     
     
         19 . A method for improving properties of a phosphate coating according to  claim 18 , wherein at least one of an applied Mn, Zn, Zn-Ca, Fe phosphate coating containing the mixture will be help to decrease the coefficient of friction at all surfaces applied.