Abstract: The invention described herein discloses a chemical mechanical machining and surface finishing process. A conversion coating is formed on the surface of a workpiece and is removed via relative motion with a tool, thereby exposing the workpiece to further reaction with the active chemistry. Low mechanical forces are used such that the plastic deformation, shear strength, tensile strength and/or thermal degradation temperature of the workpiece are not exceeded. Since the chemical mechanical machining and surface finishing process requires little force and/or speed of contact to remove the conversion coating, the equipment's mass, complexity and cost can be significantly reduced, while simultaneously increasing machining precision and accuracy. The present invention lends itself to a very controlled rate of metal removal, and can simply surface finish the workpiece, or if desired, can surface finish the workpiece simultaneously with the shaping and/or sizing process.

Abstract: A physicochemical process for refining metal surfaces which includes the steps of introducing metallic objects to be refined and a solution capable of reacting with the metal to produce a softer phosphate or oxalate conversion coating on the metal surface into a finishing unit for agitation. Agitation is carried out to produce movement among the metallic objects for conversion of the metallic surface by the solution. The mechanical and chemical action achieves a reduction in the surface roughness of the metallic objects. A burnishing step is carried out by agitating the metallic objects with a burnishing liquid to remove the conversion coating and to achieve a specular finish. The burnishing liquid contains 0.01 to 1.5 weight percent of a phosphate compound and 0.002 to 0.2 weight percent of an organic slip agent and is used at a pH of 8.5 to 10.5. The low organic content of the burnishing liquid produces a waste stream having a low oxygen demand for waste treatment facilities.

Abstract: A composition for use in the physicochemical surface refinement of objects having surfaces of titanium, nickel, and alloys of each, normally in a vibratory mass finishing process, comprises the combination of sulfamic acid, ammonium bifluoride, and hydrogen peroxide. The maximum concentration of the peroxide is controlled to avoid inhibiting or arresting the reaction with the metal; maintaining a minimum concentration prevents excessive metal dissolution, pitting and other undesirable surface defects.

Abstract: A composition for use in the physicochemical surface refinement of objects having surfaces of titanium, nickel, and alloys of each, normally in a vibratory mass finishing process, comprises the combination of sulfamic acid, ammonium bifluoride, and hydrogen peroxide. The maximum concentration of the peroxide is controlled to avoid inhibiting or arresting the reaction with the metal; maintaining a minimum concentration prevents excessive metal dissolution, pitting and other undesirable surface defects.

Abstract: A composition for use in the vibratory mass finishing of magnetic stainless steel objects contains oxalic acid, sodium m-nitrobenzene sulfonate, and sodium thiocyanate, the latter two compounds being present in specified rations to one another. The preferred compositions include a hydroxyalkyl amine; for certain applications, they most desirably also include a poly(oxyethylene)-alkyl alcohol surfactant.

Abstract: The invention provides a physicochemical process for refining relatively rough metal surfaces to a condition of high smoothness and brightness, in relatively brief periods of time, which is characterized by the use of a non-abrasive, high-density burnishing media. The process can be carried out in one step and with minimal production of media fines, thus affording economic and environmental advantages.

Abstract: A composition for use in the mass finishing of metal surfaces of objects, normally in a vibratory finishing process, utilizes the combination of oxalic acid, sodium nitrate, and hydrogen peroxide. The maximum concentration of the latter is limited to a value at which excessive dissolution of metal and pitting of the surface are avoided while, at the same time, cooperating with the nitrate to effect a substantial increase in the processing rate. Highly refined surfaces are achieved with the process in relatively short periods of time.

Abstract: Metal surfaces are refined, by the process of the invention, to high levels of smoothness in relatively short periods of time. A liquid substance is utilized to produce a conversion coating on the surface of the parts being treated, which are agitated, while being continuously wetted by the substance, in a mass finishing unit. Abrasive action causes the relatively soft coating to be removed from the high points of the surface, while leaving substantially intact the coating on the lower surface areas, with the coating being continuously repaired over metal exposed during operation. Fillage of the finishing unit container ensures efficient agitation and continuous oxygenation of the liquid substance, thereby maintaining a desirable rate of reaction and a high rate of surface leveling.

Abstract: A composition for use in the vibratory mass finishing of magnetic stainless steel objects contains oxalic acid, sodium m-nitrobenzene sulfonate, and sodium thiocyanate, the latter two compounds being present in specified rations to one another. The preferred compositions include a hydroxyalkyl amine; for certain applications, they most desirably also include a poly(oxyethylene)alkyl alcohol surfactant.