Abstract A simple and more efficient process is provided for producing deep, non-connected pit type, porous chromium surfaces with more constant and uniform characteristics. A substrate is initially electroplated with an excess of chromium having predetermined physical and chemical properties. The chromium surface is then diamond abrasive grit honed to within a specific excess of the desired final size, followed by D.C. reverse etching at a predetermined rate of ampere minutes per square inch, and finally honed with conventional type abrasive honing stones to a desired bearing surface. Under magnification, the resulting surface reveals a specific type and degree or percentage of plateaus and depressions, herein called porosity and a specific depth of pits. Simultaneously, with the surface treatment, the chromium plated product is obtained within a required size or dimension.
A method for producing a pitted porous layer of an electrodeposited chromium initially deposited in excess of the final layer thickness which comprises the steps of: honing said chromium layer with fine diamond grit of from about 40-100 grit size to remove from about 55-80% of the total chromium to be removed and to allow for subsequent D.C. reverse and final hone to said final layer thickness; D.c. reverse etching at a specific a.m.s.i. said honed surface; and honing said etched surface with an abrasive grit stone of a hardness in the range of I-M and of a grit size in the range of 100-300 to a final dimension, wherein the surface is pitted and wettable, and the pits are nonconnected.
Claim 2
Independent Claim
121 words
A method for producing a pitted porous layer of an electrodeposited chromium initially deposited in excess of the final layer thickness which comprises the steps of: honing said chromium layer with fine diamond grit of from about 40-100 grit size to remove from about 55-80% of the total chromium to be removed and to allow for subsequent D.C. reverse and final hone to said final layer thickness; D.c. reverse etching at a specific a.m.s.i. said honed surface; and honing said etched surface with an abrasive grit stone of a hardness in the range of I-M and of a grit size in the range of 100-300 to a final dimension, wherein the surface is pitted and wettable, and the pits are nonconnected.