A method for producing titanium nitride and titanium carbonitride by two-stage reduction nitriding

Abstract

The invention relates to a method for producing titanium nitride and titanium carbonitride through two-section reduction nitridation. The method comprises the following steps of (1) preparing materials: using titanium dioxide and carbon black as raw materials for mixing and uniform stirring; (2) putting the mixed powder obtained in step (1) into a high-temperature furnace to be heated; performingthermal insulation for 1 to 4 hours at 1300 to 1600 DEG C in a normal pressure argon gas environment to obtain a first-section reduction product; (3) detecting the carbon content and oxygen content ofthe first-section reduction product obtained in step (2); regulating the carbon quantity according to the relationship between the required product and raw material carbon, oxygen and nitrogen; and performing ball milling mixing; (4) putting the mixed powder obtained in step (3) into a high-temperature furnace; performing thermal insulation for 2 to 8 hours under the condition of 1600 to 1800 DEGC in the normal pressure nitrogen environment; after cooling, obtaining the titanium nitride and the titanium carbonitride. The method has the advantages that the product purity is high; the granularity is fine and uniform; the dispersion performance is good; the technical flow process is simple; the industrial production is easy; the defect of carbon content control difficulty in the productionprocess is avoided; the carbon and nitrogen proportion in the product is controllable; the produced titanium nitride and titanium carbonitride are single in phase; the oxygen content is low; and the free carbon content is very low.

Description

technical field [0001] The invention belongs to the field of cermets, and in particular relates to a preparation method of titanium nitride and titanium carbonitride. Background technique [0002] In recent years, due to the characteristics of high melting point, high hardness, low friction and wear and corrosion resistance, titanium carbonitride and titanium nitride have been widely used in the preparation of cermets, cutting tools, electrode lining materials, coating materials, etc. value. Especially in cutting tools, titanium carbonitride and titanium nitride have become a potential material to replace WC-Co cemented carbide due to their high hardness, high red hardness, high wear resistance and relatively low density. In metal cutting, titanium carbonitride and titanium nitride-based cermet tools can resist the formation of cutting nodules, peeling and pits, and the dimensional accuracy and surface quality of high-speed grinding rough machining and semi-machined workpie...

AI Technical Summary

Problems solved by technology

The problems of this method are that the use temperature is high, time-consuming, high energy consumption, high requirements on equipment, large product particles, and the introduction of sintering aids is often required, resulting in a decrease in product purity.

This method can prepare titanium carbonitride with low oxygen content, but there are three main problems: 1. Vacuum equipment is required, which is not easy for industrial production; 2. Rapid cooling device is required, which is difficult to implement industrially; 3. The C / N ratio in titanium carbonitride is controlled by controlling the nitriding time at 1300-1500°C. The principle is that titanium carbide can react with nitrogen at this temperature. Although titanium carbonitride can be produced, it will By-product elemental carbon is produced, such as shown, and this reaction will be reversed at 1600°C and above, which limits the temperature of nitriding, and the solid solution process will be very slow