Metallographic etchant, metallographic sample corrosion method and metallographic structure display method

Abstract

The invention provides a metallographic structure display method for palladium and palladium alloy metallographic samples, which includes mechanical grinding, mechanical polishing, metallographic micro-corrosion, washing and drying, and microscope observation on the palladium and palladium alloy metallographic samples. The metallographic sample includes a palladium alloy layer and a palladium layer plated on the palladium alloy layer. The metallographic etchant of the present invention is a mixed solution of nitric acid and hydrochloric acid, and its volume ratio is 3:2. The mass percentage of nitric acid used is 65% to 68%, and the mass percentage of hydrochloric acid is 36% to 38%. The metallographic structure display method of the present invention can clearly display the boundaries of the palladium layer and the palladium alloy layer, which is further conducive to the measurement of the thickness of the palladium layer and the like.

Description

【Technical field】 [0001] The invention relates to a metallographic structure observation test technology, in particular to a metallographic etchant applied to the observation of the metallographic microstructure of a surface coating, a metallographic sample corrosion method and a metallographic structure display method. 【Background technique】 [0002] The internal structure of metal materials is directly and closely related to material properties such as hardness, strength, and ductility. Metallographic observation is the most direct and effective method for studying the internal structure of metal materials. Metallographic refers to the chemical composition of metal or alloy and the physical state and chemical state of various components inside the metal or alloy. The metallographic microstructure observation method can be used to observe the boundaries and thicknesses of different metal or alloy layers. Among them, the observation of the metallographic microstructure of t...

AI Technical Summary

Problems solved by technology

[0003] However, in the prior art, the effect of performing layered metallographic microstructure display on palladium and palladium alloys is relatively poor, and the method and steps for performing metallographic microstructure display on palladium and palladium alloy layers are cumbersome

For example, electrolytic corrosion of palladium and palladium alloys will be affected by factors such as voltage, current, temperature and time, and the degree of corrosion is difficult to control

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