Copper alloy metallographic corrosion solution and corrosion method thereof

Abstract

The invention provides a copper alloy metallographic etching solution and a corrosion method thereof, and the metallographic corrosion solution is composed of the following components in percentage byvolume: 89-90% of a potassium dichromate saturated aqueous solution, 8-9% of concentrated sulfuric acid and 1-2% of a sodium chloride saturated aqueous solution, wherein the concentrated sulfuric acid comprises the following components in percentage by volume: 95-98% of H2SO4 and the balance of water. The copper alloy metallographic corrosion method comprises the following steps: taking the metallographic corrosion solution by using degreasing cotton to wipe the surface of a copper alloy sample for 1-3 times along one direction of the copper alloy, washing the copper alloy sample by using water within 2 seconds after the wiping is completed, washing and drying by blowing to obtain a copper alloy metallographic sample. By adopting the method for preparing the copper alloy metallographic sample, the metallographic structure is clear in structure, the crystal boundary is easy to distinguish, the corrosion process is stable, the corrosion time and the corrosion degree are easy to master.

Description

technical field [0001] The invention belongs to the technical field of metallographic preparation, and in particular relates to a metallographic etching solution for copper alloys with fine crystal grains and an etching method thereof. Background technique [0002] Metallography refers to the chemical composition of metals or alloys and the physical and chemical states of various components inside the metal or alloy. In polycrystals, due to the different orientations of crystal grains, there are interfaces between crystal grains, which are called grain boundaries. Since the grain boundary connects the grains with different arrangement directions, and transits from one arrangement direction to another arrangement direction, the arrangement of atoms at the grain boundary is irregular, so the atoms on the grain boundary are often larger than the atoms in the grain. have higher energy. The grain boundaries with high energy are relatively active during corrosion, and react with...

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Problems solved by technology

However, due to the weak corrosiveness of this corrosive solution, for copper alloys with fine crystal grains, this etching method often fails to achieve the desired effect. If the etching time is short, the grain boundaries cannot be fully displayed, and if the etching time is long, it is easy to Localized over-corrosion will lead to unclear grain boundaries

Therefore, the existing copper alloy metallographic corrosion solution and its corrosion method still need to be improved and developed.

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