Method for local ion nitriding of deep cavity thread of titanium alloy part

Abstract

The invention relates to a method for local ion nitriding of a deep cavity thread of a titanium alloy part, and belongs to the technical field of chemical heat treatment. The method comprises the steps of 1, manufacturing a nitriding tool according to the size and shape of the titanium alloy part; 2, carrying out vacuum annealing treatment on the nitriding tool; 3, wiping the titanium alloy part and the nitriding tool, and blow-drying the titanium alloy part and the nitriding tool through oil-free compressed air or nitrogen; 4, coating the outer wall of the titanium alloy part with the nitriding tool; 5, repeating the step 1 to the step 4 for n times, manufacturing n nitriding tools for coating the titanium alloy part, and enabling the n nitriding tools to be annularly and evenly arrangedon an ionization disc, wherein n is a positive integer; and 6, conducting nitriding treatment on the titanium alloy part. According to the method, the outer surface of the part and the non-nitrided part of the deep cavity are protected against a nitriding layer through tool design, and the temperature, time, atmosphere and electric parameters in the nitriding process are adjusted, so that the whole deep cavity thread obtains the hardness and nitriding depth of the nitriding layer meeting the technical requirements.

Description

technical field [0001] The invention belongs to the technical field of chemical heat treatment, and relates to a method for local ion nitriding of deep cavity threads of titanium alloy parts. Background technique [0002] Titanium alloy has two significant advantages of high specific strength and good corrosion resistance. It has excellent properties such as high specific strength, high fatigue performance, high corrosion resistance, low expansion coefficient, and high stability. It has good application prospects in the aerospace field. . [0003] Due to the shortcomings of titanium alloys such as low surface strength, low thermal conductivity, and poor wear resistance, titanium alloy parts are prone to adhesion and bite during assembly, and then parts fail or even break. In order to improve the wear resistance of titanium alloy, the surface strength is increased through ion nitriding surface modification treatment, thereby increasing the life of parts. [0004] Ion nitrid...

AI Technical Summary

Problems solved by technology

During deep cavity nitriding, due to the characteristics of the glow cathode pressure drop, it is difficult for the glow layer to penetrate deep into the deep cavity, resulting in the failure of nitriding in the deep cavity or uneven distribution of the depth of the nitriding layer, which cannot meet the requirements for thread wear resistance.

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