CN112475309A - Method for preparing spherical titanium nitride powder by reaction atomization method - Google Patents

Abstract

The invention discloses a method for preparing spherical titanium nitride powder by a reaction atomization method, which comprises the following steps: acid washing the surface of the titanium wire to remove an oxide layer; before milling, the atomizing reaction chamber is vacuumized and charged with N₂An active gas; preheating the titanium wire material by high-frequency induction heating equipment; then high temperature N generated by a radio frequency plasma torch₂The plasma fuses the preheated titanium wire into a continuous stream or droplets while N is present₂The plasma reacts with the liquid stream or droplets to form titanium nitride droplets; crushing and atomizing the titanium nitride liquid drops into fine liquid drops through an atomizing nozzle, condensing the fine liquid drops into spheres under the action of the surface tension of the liquid, solidifying the spheres in the cooling process to keep the shapes, and finally deeply nitriding the spheres in an atmosphere furnace to obtain the titanium nitride liquid drops. Hair brushThe stable N is established by utilizing the technology of combining high-frequency induction heating and radio frequency plasma for gas atomization powder preparation₂Plasma realizes the integration of titanium and N through plasma melting and reaction spheroidization₂The high-temperature chemical reaction to prepare the high-quality titanium nitride ceramic spherical powder.

Description

Method for preparing spherical titanium nitride powder by reaction atomization method

Technical Field

The invention belongs to the technical field of powder metallurgy, and particularly relates to a method for preparing spherical titanium nitride powder by a reaction atomization method.

Background

Titanium nitride (TiN) is a novel multifunctional cermet material, has high melting point, high hardness, acid and alkali resistance, corrosion resistance and small friction coefficient, and is a good conductor of heat and electricity. Are commonly used as coatings for titanium alloys, steel, cemented carbides and aluminum structures to improve surface properties. As a thin coating, titanium nitride is used to harden, protect the cutting and sliding surfaces, and also for decorative purposes, and also as a non-toxic external medical implant.

The traditional titanium nitride powder preparation methods, such as a metal titanium powder nitriding method, a titanium dioxide carbothermic reduction nitriding method, a gas phase method and the like, have the defects of irregular powder shape, poor flowability, great loss of service performance, low nitriding rate, long nitriding time, wide particle size range and high energy consumption. At present, no effective solution covering the above problems exists. Compared with non-spherical titanium nitride powder, the mechanical properties of spherical titanium nitride are the same in all directions, and products with excellent properties are more easily obtained in powder metallurgy and 3D printing.

Application patent CN201810089385.1 provides a method for preparing spherical titanium nitride powder by using radio frequency plasma method. The method uses non-spherical titanium powder as raw material, and the powder is melted in a plasma high-temperature zone and mixed with N₂And reacting to generate spherical titanium nitride. In the method, the raw material is non-spherical titanium powder, and when the granularity of the non-spherical titanium powder is smaller than 300 meshes, on one hand, the specific surface area of the powder is increased, so that the oxygen content of the raw material is increased, and further, the oxygen content in the titanium nitride powder obtained by spheroidization is higher; on the other hand, the powder has poor flowability, and is difficult to feed and disperse, which makes continuous production difficult.

With the rapid development of additive manufacturing (3D printing), injection molding, thermal spraying and other technologies, high-quality spherical titanium nitride powder is an important raw material necessary for the fields, the powder production has a great relationship in the whole product production process, and the quality of the powder raw material is an important guarantee for the quality of the final product.

Disclosure of Invention

In view of the above, the present invention is to provide a method for preparing spherical titanium nitride powder by a reactive atomization method, which can solve the above-mentioned problems in the prior art and realize titanium and N₂The high-purity titanium nitride spherical powder is prepared by the high-temperature chemical reaction.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a method for preparing spherical titanium nitride powder by a reaction atomization method comprises the following steps:

a) carrying out oxide layer removing treatment on a raw material pure titanium wire, specifically, putting the raw material pure titanium wire into a solution with the ratio of hydrogen fluoride to nitric acid being 1:5, carrying out ultrasonic cleaning for 5-30 minutes at 30-60 ℃, and drying for later use;

b) before milling, the atomizing reaction chamber is vacuumized to 10 DEG^-1~10^-3Pa, recharging N₂Establishing a protective atmosphere by using active gas, and adjusting the pressure of the atomization reaction chamber to-50 KPa to +50 KPa;

c) preheating the titanium wire material subjected to the oxide layer removing treatment to 500-1000 ℃ by using high-frequency induction heating equipment; then high temperature N generated by a radio frequency plasma torch in the radio frequency plasma equipment₂The preheated titanium wire material is melted into continuous liquid flow or liquid drops by the plasma, and simultaneously, the N with extremely high activity₂The plasma can rapidly react with the liquid flow or the liquid drop to generate a titanium nitride liquid drop;

d) the titanium nitride liquid drops enter an atomization reaction chamber, the titanium nitride liquid drops are crushed and atomized into fine liquid drops through an atomization nozzle, and meanwhile, the titanium nitride fine liquid drops which are not completely reacted in the step c) and N can be mixed with each other₂Continuing the reaction, condensing the fine liquid drops into a spherical shape under the action of the surface tension of the liquid, and solidifying and keeping the shape in the subsequent cooling process to obtain primary spherical titanium nitride powder;

e) and deeply nitriding the obtained preliminary spherical titanium nitride powder in an atmosphere furnace at the temperature of 1000-1400 ℃ for 1-10 hours to obtain the titanium nitride spherical powder.

Further, the radio frequency plasma modulation and stabilization in step c): using radio frequency plasma power of 30-80 KW, and stabilizing the plasma by two steps, wherein in the first step, argon is used as main gas to ignite the plasma, the flow rate is 20-40L/min, argon is used as side gas cooling and compression plasma, and the flow rate is 200-350L/min; secondly, after the plasma is stabilized, the main gas and the edge gas are respectively switched to N₂The main air flow is 20-30L/min, the side air flow is 200-300L/min, and N is measured₂After the plasma is stabilized, the smelting and atomization in the subsequent steps are carried out.

Preferably, the preliminary spherical titanium nitride powder in step e) is deeply nitrided in an atmosphere furnace at 1200 ℃.

The invention has the following beneficial effects: 1) according to the invention, the high-purity titanium wire material is used as a raw material instead of titanium powder, so that the carrying of adsorbed gas, moisture and the like from the powder raw material is reduced, the limitation of the purity and granularity of the raw material for powder preparation by sending powder by using a radio frequency plasma technology alone is avoided, and the high-purity spherical titanium nitride powder with lower oxygen content can be obtained; 2) the invention adopts the technology of combining induction heating with radio frequency plasma and gas atomization, and the whole heating, melting, nitriding and gas atomization processes are carried out in N₂As a reaction gas and N₂No other gas pollution and no electrode pollution under the protective atmosphere; 3) the invention uses N₂The plasma gas is adopted, the heat enthalpy value of the plasma is improved, and the production efficiency of melting is improved; 4) the invention uses two-step synthesis process (plasma reaction spheroidization and deep nitridation) to deeply nitride the spherical titanium nitride powder, thereby improving the nitrogen content of the spherical titanium nitride powder.

Drawings

FIG. 1 shows titanium nitride powder prepared in example 1 of the present invention;

FIG. 2 shows titanium nitride powder prepared in example 2 of the present invention;

FIG. 3 shows titanium nitride powder prepared in example 3 of the present invention.

Detailed Description

So that the manner in which the features and aspects of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings.

The invention relates to a method for preparing spherical titanium nitride powder by a reaction atomization method, which comprises the following steps:

a) carrying out oxide layer removing treatment on a raw material pure titanium wire, specifically, putting the raw material pure titanium wire into a solution with the ratio of hydrogen fluoride to nitric acid being 1:5, carrying out ultrasonic cleaning for 5-30 minutes at 30-60 ℃, and drying for later use;

in the method, the titanium wire is subjected to oxide layer removing treatment, and the high-purity titanium wire is used instead of titanium powder as a raw material, so that the carrying of adsorbed gas, moisture and the like from the powder raw material is reduced, the limitation of the purity and the granularity of the raw material for powder preparation by powder conveying by using a radio frequency plasma technology alone is avoided, and high-purity spherical titanium nitride powder with lower oxygen content can be obtained;

b) before milling, the atomizing reaction chamber is vacuumized to 10 DEG^-1~10^-3Pa, recharging N₂Establishing a protective atmosphere by using active gas, and adjusting the pressure of the atomization reaction chamber to-50 KPa to +50 KPa;

c) preheating the titanium wire to 500-1000 ℃ by using high-frequency induction heating equipment; then high temperature N generated by a radio frequency plasma torch in the radio frequency plasma equipment₂The preheated titanium wire material is melted into continuous liquid flow or liquid drops by the plasma, and simultaneously, the N with extremely high activity₂The plasma can rapidly react with the liquid flow or the liquid drop to generate a titanium nitride liquid drop;

the above radio frequency plasma modulation and stabilization: preferably, the power of radio frequency plasma is 30-80 KW, the plasma is stabilized in two steps, in the first step, argon is used as main gas to ignite the plasma, the flow is 20-40L/min, argon is used as side gas cooling and compression plasma, and the flow is 200-350L/min; secondly, after the plasma is stabilized, the main gas and the edge gas are respectively switched to N₂The main air flow is 20-30L/min, the side air flow is 200-300L/min, and N is measured₂After the plasma is stabilized, the smelting and atomization of the subsequent steps can be carried out;

the technology of combining high-frequency induction heating and preheating of the titanium wire and radio frequency plasma melting solves the problem of low yield caused by limited heat absorption rate of the titanium wire in a simple induction melting or plasma melting process, and increases the yield per unit time; in the process of radio frequency plasma melting, the superheat degree of titanium nitride liquid flow or liquid drops is improved;

d) the titanium nitride liquid drops enter an atomization reaction chamber, the titanium nitride liquid drops are crushed and atomized into fine liquid drops through an atomization nozzle, and meanwhile, the titanium nitride fine liquid drops which are not completely reacted in the step c) and N can be mixed with each other₂Continuing the reaction, condensing the fine liquid drops into a spherical shape under the action of the surface tension of the liquid, and solidifying and keeping the shape in the subsequent cooling process to obtain primary spherical titanium nitride powder;

the gas atomization nozzle is used for atomizing titanium nitride liquid drops melted by radio frequency plasma, so that the problem that the high-quality fine spherical titanium nitride powder cannot be obtained by independently using a radio frequency plasma torch to melt a titanium wire raw material is solved, and the high-quality fine spherical titanium nitride powder can be obtained;

e) and deeply nitriding the obtained preliminary spherical titanium nitride powder in an atmosphere furnace at the temperature of 1000-1400 ℃ for 1-10 hours to obtain the titanium nitride spherical powder.

The invention uses N₂The method has the advantages that the method is plasma gas, the enthalpy value of the plasma is improved, the production efficiency is improved when melting is carried out, and the nitrogen content of the spherical titanium nitride powder is improved by deep nitriding the spherical titanium nitride powder through plasma reaction spheroidization and deep nitriding processes.

EXAMPLE 1

a) Putting the titanium wire into a solution with the ratio of hydrogen fluoride to nitric acid being 1:5, ultrasonically cleaning the titanium wire for 20 minutes at 50 ℃, and drying the titanium wire for later use;

b) before milling, the atomizing reaction chamber is vacuumized to 10 DEG^-1Pa, recharging N₂Establishing a protective atmosphere by using active gas, and adjusting the pressure of an atomization reaction chamber to +50 Kpa;

c) preheating the titanium wire to 500 ℃ by using high-frequency induction heating equipment; then high temperature N generated by a radio frequency plasma torch in the radio frequency plasma equipment₂The preheated titanium wire material is melted into continuous liquid flow or liquid drops by the plasma, and simultaneously, the N with extremely high activity₂Plasma bodyRapidly reacting with the liquid stream or droplets to produce titanium nitride droplets;

the above radio frequency plasma modulation and stabilization: using radio frequency plasma power of 50KW, and stabilizing the plasma by two steps, wherein in the first step, argon is used as main gas to ignite the plasma, the flow is 30L/min, argon is used as side gas cooling and compression plasma, and the flow is 250L/min; secondly, after the plasma is stabilized, the main gas and the edge gas are respectively switched to N₂Main air flow of 20L/min, side air flow of 200L/min, wait for N₂After the plasma is stabilized, carrying out subsequent smelting and atomization;

d) the titanium nitride liquid drops enter an atomization reaction chamber, the titanium nitride liquid drops are crushed and atomized into fine liquid drops through an atomization nozzle, and meanwhile, the titanium nitride fine liquid drops which are not completely reacted in the step c) and N can be mixed with each other₂Continuing the reaction, condensing the fine liquid drops into a spherical shape under the action of the surface tension of the liquid, and solidifying and keeping the shape in the subsequent cooling process to obtain primary spherical titanium nitride powder;

e) and deeply nitriding the obtained preliminary spherical titanium nitride powder in an atmosphere furnace at 1200 ℃ for 5 hours to obtain the titanium nitride spherical powder, wherein the titanium nitride spherical powder is shown in figure 1.

EXAMPLE 2

a) Putting the titanium wire into a solution with the ratio of hydrogen fluoride to nitric acid being 1:5, ultrasonically cleaning the titanium wire for 30 minutes at 30 ℃, and drying the titanium wire for later use;

b) before milling, the atomizing reaction chamber is vacuumized to 10 DEG^-2Pa, recharging N₂Establishing a protective atmosphere by using active gas, and adjusting the pressure of the atomization reaction chamber to 10 Kpa;

c) preheating the titanium wire to 1000 ℃ by using high-frequency induction heating equipment; then high temperature N generated by a radio frequency plasma torch in the radio frequency plasma equipment₂The preheated titanium wire material is melted into continuous liquid flow or liquid drops by the plasma, and simultaneously, the N with extremely high activity₂The plasma can rapidly react with the liquid flow or the liquid drop to generate a titanium nitride liquid drop;

the above radio frequency plasma modulation and stabilization: the plasma was stabilized in two steps using RF plasma power of 60KW, the first step, using argonThe gas is main gas ignition plasma, the flow rate is 35L/min, the argon gas is side gas cooling and compression plasma, and the flow rate is 300L/min; secondly, after the plasma is stabilized, the main gas and the edge gas are respectively switched to N₂The main air flow is 25L/min, the side air flow is 250L/min, and the quantity is N₂After the plasma is stabilized, carrying out subsequent smelting and atomization;

d) the titanium nitride liquid drops enter an atomization reaction chamber, the titanium nitride liquid drops are crushed and atomized into fine liquid drops through an atomization nozzle, and meanwhile, the titanium nitride fine liquid drops which are not completely reacted in the step c) and N can be mixed with each other₂Continuing the reaction, condensing the fine liquid drops into a spherical shape under the action of the surface tension of the liquid, and solidifying and keeping the shape in the subsequent cooling process to obtain primary spherical titanium nitride powder;

e) and deeply nitriding the obtained preliminary spherical titanium nitride powder in an atmosphere furnace at 1300 ℃ for 6 hours to obtain titanium nitride spherical powder, wherein the titanium nitride spherical powder is shown in figure 2.

EXAMPLE 3

a) Putting the titanium wire material into a solution with the ratio of hydrogen fluoride to nitric acid being 1:5, performing ultrasonic cleaning for 10 minutes at 60 ℃, and drying for later use;

b) before milling, the atomizing reaction chamber is vacuumized to 10 DEG^-3Pa, recharging N₂Establishing a protective atmosphere by using active gas, and adjusting the pressure of the atomization reaction chamber to-10 Kpa;

c) preheating the titanium wire to 800 ℃ by high-frequency induction heating equipment; then high temperature N generated by a radio frequency plasma torch in the radio frequency plasma equipment₂The preheated titanium wire material is melted into continuous liquid flow or liquid drops by the plasma, and simultaneously, the N with extremely high activity₂The plasma can rapidly react with the liquid flow or the liquid drop to generate a titanium nitride liquid drop;

the above radio frequency plasma modulation and stabilization: using radio frequency plasma power of 40KW, and stabilizing the plasma by two steps, wherein in the first step, argon is used as main gas to ignite the plasma, the flow is 25L/min, argon is used as side gas cooling and compression plasma, and the flow is 300L/min; secondly, after the plasma is stabilized, the main gas and the edge gas are respectively switched to N₂Main air flow 20L-min, the flow rate of the waste gas is 300L/min, and N is required₂After the plasma is stabilized, carrying out subsequent smelting and atomization;

d) the titanium nitride liquid drops enter an atomization reaction chamber, the titanium nitride liquid drops are crushed and atomized into fine liquid drops through an atomization nozzle, and meanwhile, the titanium nitride fine liquid drops which are not completely reacted in the step c) and N can be mixed with each other₂Continuing the reaction, condensing the fine liquid drops into a spherical shape under the action of the surface tension of the liquid, and solidifying and keeping the shape in the subsequent cooling process to obtain primary spherical titanium nitride powder;

e) and deeply nitriding the obtained preliminary spherical titanium nitride powder in an atmosphere furnace at 1200 ℃ for 8 hours to obtain titanium nitride spherical powder, wherein the titanium nitride spherical powder is shown in figure 3.

The specific type of the above-mentioned devices is not limited and detailed, and the deep connection mode of the above-mentioned devices is not detailed, and can be understood by those skilled in the art as the common general knowledge.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, and any modifications, equivalents, improvements, etc. that are within the spirit and principle of the present invention should be included in the present invention.

Claims (3)

1. A method for preparing spherical titanium nitride powder by a reaction atomization method is characterized by comprising the following steps:

a) carrying out oxide layer removing treatment on a raw material pure titanium wire, specifically, putting the raw material pure titanium wire into a solution with the ratio of hydrogen fluoride to nitric acid being 1:5, carrying out ultrasonic cleaning for 5-30 minutes at 30-60 ℃, and drying for later use;

b) before milling, the atomizing reaction chamber is vacuumized to 10 DEG^-1~10^-3Pa, recharging N₂Establishing a protective atmosphere by using active gas, and adjusting the pressure of the atomization reaction chamber to-50 KPa to +50 KPa;

c) preheating the titanium wire material subjected to the oxide layer removing treatment to 500-1000 ℃ by using high-frequency induction heating equipment; then high temperature N generated by a radio frequency plasma torch in the radio frequency plasma equipment₂Plasma will beThe preheated titanium wire is melted into a continuous liquid flow or liquid drops, and the activity of N is extremely high₂The plasma can rapidly react with the liquid flow or the liquid drop to generate a titanium nitride liquid drop;

d) the titanium nitride liquid drops enter an atomization reaction chamber, the titanium nitride liquid drops are crushed and atomized into fine liquid drops through an atomization nozzle, and meanwhile, the titanium nitride fine liquid drops which are not completely reacted in the step c) and N can be mixed with each other₂Continuing the reaction, condensing the fine liquid drops into a spherical shape under the action of the surface tension of the liquid, and solidifying and keeping the shape in the subsequent cooling process to obtain primary spherical titanium nitride powder;

e) and deeply nitriding the obtained preliminary spherical titanium nitride powder in an atmosphere furnace at the temperature of 1000-1400 ℃ for 1-10 hours to obtain the titanium nitride spherical powder.

2. The method for preparing spherical titanium nitride powder by the reactive atomization method according to claim 1, wherein the radio frequency plasma modulation and stabilization in step c): using radio frequency plasma power of 30-80 KW, and stabilizing the plasma by two steps, wherein in the first step, argon is used as main gas to ignite the plasma, the flow rate is 20-40L/min, argon is used as side gas cooling and compression plasma, and the flow rate is 200-350L/min; secondly, after the plasma is stabilized, the main gas and the edge gas are respectively switched to N₂The main air flow is 20-30L/min, the side air flow is 200-300L/min, and N is measured₂After the plasma is stabilized, the smelting and atomization in the subsequent steps are carried out.

3. The method for preparing spherical titanium nitride powder by a reaction atomization method according to claim 1, wherein the preliminary spherical titanium nitride powder in the step e) is subjected to deep nitridation in an atmosphere furnace at 1200 ℃.

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