Metallographic corrosive agent suitable for multi-component aluminum alloy and corrosion method of metallographic corrosive agent

Abstract

The invention discloses a metallographic corrosive agent suitable for a multi-component aluminum alloy and a corrosion method of the metallographic corrosive agent. According to the formula of the corrosive agent, every 100 ml of the corrosive agent comprises 0.5-2 g of NaF, 4-10 ml of HCl with the concentration being 36%, 1-3 ml of HNO3 with the concentration being 66%, 1-3 ml of CH3OH and 82-95 ml of H2O. The method comprises the following steps: (1) quantitatively taking a metallographic corrosive agent; (2) grinding the multi-component aluminum alloy sample with metallographic abrasive paper, and polishing the multi-component aluminum alloy sample into a mirror surface; (3) uniformly smearing a corrosive agent on the surface of the sample; (4) corroding the sample under a certain temperature condition, starting timing when the corrosive agent is in contact with the surface of the aluminum alloy, and keeping the corrosion for a period of time; and (5) after completion, washing with cleaning fluid and blow-drying. The corrosion agent does not contain an HF solution, the danger of the corrosion agent in the preparation process is reduced, and the corrosion agent is wide in application range and suitable for various series of aluminum alloys.

Description

technical field [0001] The invention relates to a metallographic etchant for aluminum alloys and a corrosion method thereof, in particular to a metallographic etchant suitable for multi-component aluminum alloys and a corrosion method thereof. Background technique [0002] Aluminum alloys have many excellent properties, such as small mass, high hardness, corrosion resistance, and good thermal conductivity. These excellent properties make light-weight and high-strength aluminum alloys have broad applications in the aerospace field. The most widely used aluminum alloys in aerospace are 2000 series, 5000 series, 6000 series, 7000 series, etc. At present, the common aluminum alloy etchant is Keller reagent (the ratio is: 1mlHF+1.5mlHNO 3 +1.5HCl+95ml H 2 O) and Weck reagent (the ratio is: 100ml H 2 O+4g KMnO 4 +1 g NaOH). Some related patents also report formulations of multi-component aluminum alloy etchants different from the above two reagents, such as H 2 SO 4 Corros...

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Problems solved by technology

[0004] (1) HF needs to be used in the preparation of corrosive agents, which has great potential safety hazards;

[0005] (2) The metallographic structure corroded by common corrosive agents is not clear, and it is difficult to see the grain boundary;

[0006] (3) Many corrosive agents only target single or several aluminum alloys, and have poor corrosion effects on most aluminum alloys;

[0007] (4) The Keller reagent and the Weck reagent have extremely high requirements on the corrosion time, and the corrosion time of the sample is not easy to control. If a little more corrosion is performed for 1 second, over-corrosion will occur;

[0008] (5) Many corrosive agents and corrosion methods have high temperature restrictions, and the scope of application is small;

[0009] (6) Anode coating sample preparation is more troublesome, and the success rate is low, which affects the experimental efficiency

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