Sample preparation method for fracture of tungsten carbide coating on magnesium-alloy surface via scanning electron microscope

Abstract

The invention discloses a sample preparation method for the fracture of a tungsten carbide coating on a magnesium-alloy surface via a scanning electron microscope. The sample preparation method comprises the following specific steps of: cutting a magnesium-alloy test sample into small-size cuboids by cutting equipment; cutting a magnesium-alloy matrix by high-accuracy cutting equipment to obtain a magnesium-alloy sheet test sample; cutting a notch at the opposite positions of the two long sides of the magnesium-alloy sheet test sample by the cutting equipment respectively; ultrasonically cleaning by absolute ethyl alcohol; soaking the magnesium-alloy sheet test sample in liquid nitrogen until a heat balance is achieved; breaking the magnesium-alloy sheet test sample; and taking out the magnesium-alloy sheet test sample from liquid nitrogen, placing the magnesium-alloy sheet test sample on filter paper, immediately blow-drying by a blower, and then obtaining the clean and regular fracture test sample of the magnesium-alloy sheet test sample. The sample preparation method disclosed by the invention has the following advantages that: 1, the sample preparation method is simple and convenient; 2, the obtained test sample is clean and pollution-free; and 3, the obtained test sample is regular and beneficial to the morphology analysis and test of the scanning electron microscope.

Description

(1) Technical field: [0001] The invention relates to a scanning electron microscope sample preparation method, in particular to a scanning electron microscope sample preparation method for the fracture of a tungsten carbide coating on the surface of a magnesium alloy. (two) background technology: [0002] Magnesium alloy is an alloy composed of magnesium and other elements. It is characterized by low density, high specific strength, large elastic modulus, good heat dissipation, good shock absorption, strong impact load capacity, and resistance to organic and alkali corrosion. it is good. The main alloying elements of magnesium alloys are aluminum, zinc, manganese, cerium, thorium, and a small amount of zirconium or cadmium. Currently, magnesium-aluminum alloys are the most widely used. Magnesium-aluminum alloys are mainly used in aviation, aerospace, transportation, chemical, rocket and other industries. department. The specific gravity of magnesium is about 2 / 3 of that of...

AI Technical Summary

Problems solved by technology

The metallographic samples obtained by using the traditional metallographic sample preparation method, because the hardness difference between the magnesium alloy and the tungsten carbide coating is too large, the obtained samples all contain a stepped structure, and in the stepped structure area, the gold During the phase sample preparation process, there will be a large amount of residual substances and other pollutants, which will affect the observation effect of the bonding between the coating and the substrate, and in the analysis of the components of the scanning electron microscope energy spectrum, the residual substances and other pollutants will interfere too much with the experimental data. , but no accurate data can be obtained. The electron microscope photos of the fracture samples obtained by ordinary metallographic sample preparation are shown in figure 1

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