Method for preparing TiCN coating on surface of screw tap

Abstract

The invention discloses a method for preparing a TiCN coating on a surface of a screw tap. The method comprises the following steps that after the screw tap made from high-speed steel is treated in advance, the screw tap is placed on a rotating frame rod of electric arc ion coating equipment, a Ti target is used as a Ti element source for preparing the TiCN coating, and a sputtering rate of the Titarget is controlled through a current of an arc power supply; high-purity Ar is adopted as a main ionization gas, high-purity N2 and high-purity CH2 are adopted as reaction gases, the N2 gas and theCH2 gas are enabled to be ionized and combined with the Ti element, and the TiCN coating is formed on the surface of the screw tap; and the prepared TiCN coating is of a multi-layer structure, namelya Ti / TiN / TiCN / TiN / TiCN structure. The total thickness of the TiCN is 2 microns, the TiCN coating comprises the following atomic components of 52at.% of Ti, 28at.% of C and 20at.% of N; coating hardness is HV3000, under the condition of room temperature dry friction and GCr15 friction pairs, a friction coefficient of the coating is 0.15 through detection by a pin-on-disc test, the coating has excellent antifriction performance, and the method is suitable for being applied to tapping machining of refractory materials.

Description

technical field [0001] The invention belongs to the technical field of application of coatings in cutting tools, relates to the preparation of coatings on the surface of cutting tools, and further relates to a method for preparing TiCN coatings on the surface of taps. Background technique [0002] Tap is a tool for processing various small and medium-sized internal threads. It has a simple structure and is easy to use, and is widely used in production. According to the way of use, it can be divided into hand taps and machine taps. Generally, high-speed steel or cemented carbide molar taps with high manufacturing precision are called machine taps, and carbon tool steel or alloy tool steel hobbing (or cutting) Tooth) taps are called hand taps. In fact, the structure and working principle of the two are basically the same. Generally, a tap consists of a working part and a shank. The working part is divided into a cutting part and a calibration part. The former is ground with ...

AI Technical Summary

Problems solved by technology

[0003] 1. Poor chip removal causes chip blockage and breakage;

[0004] 2. Tooth collapse caused by too much cutting thickness of each tooth of the tap;

[0005] 3. The tap is severely worn due to excessive speed, improper selection of cutting fluid, and excessive hardness of the workpiece material when tapping the thread of the tap.

When the nitrogen content is zero, it is a TiC coating, and the appearance is dark gray. The hardness of the TiC coating reaches the maximum HV3500, but the toughness drops sharply, which is not suitable for the surface coating application of taps.

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