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Metallographic erosion method for displaying cobalt-chromium alloy structure

A metallographic erosion, cobalt-chromium alloy technology, applied in the field of metallographic erosion, can solve problems such as poor effect, and achieve the effect of accurate metallographic structure and good erosion effect

Inactive Publication Date: 2013-03-20
725TH RES INST OF CHINA SHIPBUILDING INDAL CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, according to the author's test, these corrosive agents either do not erode, or the effect is very poor

Method used

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  • Metallographic erosion method for displaying cobalt-chromium alloy structure
  • Metallographic erosion method for displaying cobalt-chromium alloy structure
  • Metallographic erosion method for displaying cobalt-chromium alloy structure

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] The test material is a cobalt-chromium alloy tube for human implantation. The alloy ratio is: C: 0.05-0.15; Mg: 1.00-2.00; Si: ≤0.40; P: ≤0.040; S: ≤0.030; Cr: 19-21; Ni: 9-11; W: 14-16; Fe: ≤3; the balance is Co and unavoidable impurities.

[0033] The aqua regia in Example 1 refers to the mixed solution of nitric acid with a mass concentration of 69% and hydrochloric acid with a mass concentration of 36.5%, according to the volume ratio of nitric acid: hydrochloric acid = 1:3.

[0034] The room temperature is 28°C, when the prepared aqua regia is left for 7 minutes, the color of the aqua regia is dark yellow, and at this time, dip the cotton to wipe the sample, and the wiping time is about 50 seconds. When the test surface is no longer bright and slightly dark, the erosion effect is the best at this time, the surface of the sample is clear, the grain boundaries are clear, and the structure is twin crystal α, see Figure 4 .

Embodiment 2

[0036] The test material is a cobalt-chromium alloy pipe for human implantation. The alloy ratio is: C: 0.05-0.15; Mg: 1.00-2.00; Si: ≤0.40; P: ≤0.040; S: ≤0.030; Cr: 19-21; Ni : 9-11; W: 14-16; Fe: ≤3; the balance is Co and unavoidable impurities.

[0037] The aqua regia in Example 2 refers to the mixed solution of nitric acid with a mass concentration of 69% and hydrochloric acid with a mass concentration of 36.5%, according to the volume ratio of nitric acid: hydrochloric acid = 1:3.

[0038] The room temperature is 28°C. When the prepared aqua regia is left for 1 minute, the color of the aqua regia is dark yellow. At this time, dip the cotton to wipe the sample, and the wiping time is about 60 seconds. When the test surface is no longer bright and slightly dark, the erosion effect is the best at this time, the surface of the sample is clear, the grain boundaries are clear, and the structure is twinned α.

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Abstract

The present invention describes a metallographic erosion method for displaying a cobalt-chromium alloy structure, including: preparing aqua regia; placing the aqua regia at a certain temperature for a specified time to make the aqua regia reach the chroma meet the requirements; dipping in the aqua regia with a flexible material to wipe a sample, wherein the wiping time is 30-90 seconds; removing the surface aqua regia; and drying to get a etched sample surface. The method of the present invention is clearly, completely and accurately displays the metallographic structure of the cobalt-chromium alloy. The good erosion effect of the reagent is reflected by a test of a cobalt-chromium alloy human body implantable material. According to the present invention, the cobalt-chromium alloy etchant is prepared by a conventional metallographic etchant, good erosion effect of cobalt-chromium alloy is achieved by using that the erosion abilities of the etchant during different periods are different, thus a clear, complete and accurate metallographic structure is displayed.

Description

technical field [0001] The invention relates to a metallographic etching method, in particular to a metallographic etching method showing cobalt-chromium alloy structure. Background technique [0002] Cobalt-chromium alloy has small specific gravity, light weight, high melting point, stable chemical properties, strong corrosion resistance, excellent mechanical properties, and no irritation to the body. It is currently widely used in human body implant materials. Because it is difficult to corrode, metallographic sample preparation is a difficult point. After consulting many metallographic sample preparation technical materials, no specific corrosion method for cobalt-chromium alloys has been found. Only the etchant of cobalt-based alloys is mainly hydrochloric acid + water + acetic acid + nitric acid + Solution, alcohol + hydrofluoric acid + nitric acid, hydrochloric acid + copper sulfate aqueous solution and lactic acid + heavy water + nitric acid. However, according to th...

Claims

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Application Information

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IPC IPC(8): G01N1/32C23F1/28
Inventor 王春芬李雪峰郭海霞
Owner 725TH RES INST OF CHINA SHIPBUILDING INDAL CORP
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