Polishing Of Copper Research Articles

Ion polishing of copper: some observations

The change in absorptivity at 10.6 microm of copper samples, at various stages of polishing including ion polishing, is reported. The ion polishing apparatus is also described; it employs a low energy Xe ion beam incident at a glancing angle to maximize the removal rate while minimizing ion penetration and damage. The sample to be polished is rotated and the beam scanned across the surface to produce uniform removal of material. Starting with single crystal copper that had been mechanically polished and by using combinations of ion polishing and vacuum annealing, the absorptivity, determined by calorimetry, was reduced from 0.92% to 0.76%. Although optical figure and scatter were not monitored, SEM pictures show that the surface features become smoother with ion polishing. A similar experiment was performed on a single crystal copper sample that had been electropolished, and the combination of ion polishing and annealing lowered the absorptivity from 0.97% to 0.89%.

Potentiostatic controlled etching and polishing of copper and its alloys

The attempt to apply the potentiostatic method in study of anodic dissolution of copper and its alloys for metallographic purposes is presented. The results of copper and Cu−0.5% Be, Cu−1% Zr, and Cu−0.3% Be−2% Ni alloys examination in 85% phosphoric acid are published in the previous paper [A. Mance, Metallography 4, 287–296 (1971)]. It has been found that only Cu−1% Zr alloy has a polarization curve with passivation step. For good polishing of all three alloys, potentials more than −250 mV (SSE) are recommended. This paper gives the results of examination of mentioned three alloys in 50% citric acid. Optimal conditions for revealing microstructure have been determined It has been found that selective anodic dissolution in citric acid occurs in a wide potential range from about −300 mV to +1000 mV.

Potentiostatic etching and polishing of copper and its alloys

An attempt to apply the potentiostatic method to the study of anodic dissolution of copper and its alloys for metallographic purposes is reported. Copper and Cu-0.5% Be, Cu-1% Zr, and Cu-0.3% Be-2% Ni alloys were examined in 85% phosphoric acid, and the polarization curves were determined. A number of specimens were treated at potentials and current densities defined by polarization curves The results indicate the relationship between the processes taking place on the anode at a given region of the polarization curves and the revealing of the microstructure components. Optimal conditions for revealing microstructure have been determined.

Design and Use of an Acid Polishing Machine

An improved acid polishing machine for dislocation-free polishing of copper is reported and its operation described. The main improvements are a compact axial tilt device, provision for rapid interruption of the polishing and inspection of the sample, and a more rigid shaft confinement and alignment. Some useful aids in the chemical polishing techniques are also reported.

Electrolytic processes for surface conditioning of metals

The uses of electrolysis, for the surface cleaning and descaling of metals, for improving the resistance of aluminium and its alloys to oxidation and abrasion, and for the polishing of metals, are discussed.Compared with direct-immersion processes, electrolytic cleaning and descaling is often speedier, more efficient and easier to control. In cathodic cleaning, adventitious matter is loosened by the nascent hydrogen evolved on the surface of the work, while the gas itself is a powerful reducing agent. Anodic pickling in acid electrolytes is precise in action and avoids the dangers of hydrogen embrittlement and of over-pickling. Alternate anodic and cathodic procedures offer certain advantages that are leading to their wider adoption.Theory and practice in the anodic oxidation of aluminium are discussed; reference is made to the use of this type of process to facilitate photographic reproduction on the surface of the metal, and to modifications of anodizing technique designed to produce especially hard, wear-resisting films.The principles of electrolytic polishing are explained. Industrial practice in the electrolytic polishing of steel, nickel, copper and aluminium is outlined. A comparison is drawn between electrolytic and mechanical polishing, and some reference is made to the economics of the electrolytic process.

Discussion of “The Anode Layer in the Electrolytic Polishing of Copper” [H. F. Walton (pp. 219–226)

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The Anode Layer in the Electrolytic Polishing of Copper

The viscosities and electrical conductivities of solutions of in aqueous phosphoric acid and phosphoric acid‐glycerol‐ethylene glycol mixtures were measured with a view to investigating the anode layer formed when copper is electrolytically polished in these solutions. Dissolved copper was found to raise the viscosity considerably, the increase being greater in the mixtures with glycol and glycerol than in phosphoric acid alone. The copper concentration near the anode during electrolysis was measured, and current‐voltage relationships were studied using a rotating copper anode. The effective thickness of the anode layer was estimated to be about 10−3 cm.

銅の電解研磨に就いて

The experiments on the electrolytic polishing of copper have been performed according to Jacquet's method, and furthermore the microstructural tests on the workhardened and the electrolytic deposited copper also have been carried out by the same method. The results of the writer's experiments are summarized as follows; (1) The time of electrolysis has a remarkable effect on the relationship between the current density of anode and the voltage of cell. (2) The writer should like to recommend the following conditions to get the mirror-like surface of the copper. (i) Anode: Test piece as anode, vertically set parallel to cathode about 25mm apart. (ii) Cathode: Copper plate. (iii) Electrolyte: 50% aqueous solution of H3PO4 of specific gravity 1.75. (iv) Voltage of cell: 1.6 V. (v) Current density of anode: About 6A/dm2, being regulated to keep voltage of cell to 1.6 V. (vi) Solution temperature: 25° (vii) Polishing time: 5_??_15min. (3) By the microscopic tests, the writer should like to point out that the lapping may have the effect to the depth from the surface about 0.06mm on the grain size and the hardness of the annealed copper. (4) And that the crystal grains of the electrolytic deposited copper is to be perfectly continuous with the base copper on the anodically polished surfaces, but to be discontinuous on the surfaces which are lapped or polished with emery paper, and be partially continuous on the surfaces which are etched by 10% aqueous solution of (NH)2S2O8.

Electrolytic Polishing

An investigation of the electrolytic polishing of copper by the Jacquet method has thrown new light on the mechanism responsible for the polishing action. From a study of the voltage-current curves it is concluded that when conditions are right for polishing the concentration of dissolved copper at the anode is the highest possible. Accordingly the concentration gradient which exists at the anode limits the rate at which copper can dissolve,i.e., diffuse into the bulk of the electrolyte (orthophosphoric acid). Since there is greater diffusion from raised areas of the anode because of steeper concentration gradients near them, the surface will become progressively more nearly level. The surface does not etch for the concentration gradient alone controls the rate of solution. Details are given for the electrolytic polishing of iron with an orthophosphoric acid electrolyte. A convenient form of cell for electrolytic polishing is described.