RU2805065C1 - Method for producing titanium diboride powder - Google Patents

Abstract

FIELD: inorganic chemistry.

SUBSTANCE: invention can be used in the production of titanium diboride. The method of obtaining titanium diboride powder involves using X-ray amorphous boron powder and titanium powder with particle sizes of no more than 5 microns, taken in an atomic ratio of (2.1–12):1, mixing them for 20 minutes at the ratio of the mass of ball mill balls to the total mass of powders of 3:1. The resulting mixture is distributed over the surface of graphite paper, previously laid inside a vertically located first graphite glass, which is covered with a graphite lid, and coaxially placed inside a second graphite glass of a larger diameter, which is the cathode. After this, an arc discharge is ignited in the air by contacting the anode in the form of a solid graphite rod with the upper surface of the graphite cover at a current of 150 A for 20 s. Then the anode is pulled vertically upward, interrupting the combustion of the electric arc discharge. After cooling to room temperature, remove the graphite lid from the first graphite glass, remove the graphite paper from it and collect the finished product deposited on its surface. Used graphite paper is disposed.

EFFECT: invention makes it possible to obtain titanium diboride TiB₂ powder in an air atmosphere and to reduce the production time.

1 cl, 4 dwg, 1 tbl

Description

The invention relates to inorganic chemistry, namely to the production of compounds with boron and can be used to obtain titanium diboride powder.

There is a known method for producing titanium diboride by self-propagating high-temperature synthesis [Borovinskaya I.P., Merzhanov A.G. Metallothermic processes in chemistry and metallurgy. Novosibirsk "Science". 1971. P. 58].

However, this technology is complex and involves the use of shielding gas.

There is a known method for producing titanium diboride [G.V. Samsonov, T.I. Serebryakova, V.A. Neronov. Borides. M.: Atomizdat, 1975, p. 108], in which titanium diboride is obtained in vacuum by reacting titanium oxide with boron carbide with the addition of soot.

The disadvantage of this method is the need to first obtain dispersed powders of titanium oxide and boron carbide, which requires the organization of a complex multi-stage technological cycle.

There is a known method for producing titanium diboride [RU 25594829 C2, IPC C01B 35/04 ( 2006.01), B82B 1/00 (2006.01), B82Y 30/00 (2011.01), publ.: 08.10.2015], which consists of heating a charge from a mixture of dioxide titanium, a chemical reagent containing boron, and carbon material at a temperature of 1500-1700°C for 20-25 minutes. Mixing of the charge components is carried out by joint sifting. Highly dispersed nanofibrous carbon powder with a specific surface area of 138-160 m2/g is used as a carbon material. The charge is loaded into a glassy carbon crucible with an internal diameter of 15 mm and an internal height of 60 mm. The internal volume of the crucible is 10.603 cm ³ . With a charge density of 2.5 g/cm3, its mass is approximately 26 g. The glassy carbon crucible is covered with a graphite lid and placed in a quartz reactor, which in turn is inserted into the inductor of an induction furnace. To prevent nitriding of boron carbide, the quartz reactor is purged with argon.

The disadvantage of this method is the long process and the use of argon to purge the reactor.

The technical result of the proposed method is the production of titanium diboride powder in an air atmosphere under normal conditions, as well as reducing the time for obtaining titanium diboride powder.

A method for producing titanium diboride powder includes using X-ray amorphous boron powder and titanium powder with particle sizes of no more than 5 microns, taken in an atomic ratio (2.1-12):1, mixing them for 20 minutes at a ratio of the mass of ball mill balls to the total mass of powders as 3:1. The resulting mixture is distributed over the surface of graphite paper, previously laid inside a vertically located first graphite glass, which is covered with a graphite lid and coaxially placed inside a second graphite glass of larger diameter. After this, an arc discharge is ignited in the air by contacting the anode in the form of a solid graphite rod with the upper surface of the graphite cover at a current of 150 A for 20 s. Then the anode is pulled vertically upward, interrupting the combustion of the electric arc discharge. After cooling to room temperature, remove the graphite lid from the first graphite glass, remove the graphite paper from it and collect the finished product deposited on its surface. Used graphite paper is disposed of.

Thus, the proposed method makes it possible to obtain titanium diboride powder in an air atmosphere and reduce the time for its production.

In fig. Figure 1 shows a diagram of a device for producing powder based on titanium diboride.

In fig. Figure 2 shows the X-ray diffraction pattern of the resulting powder based on titanium diboride at a boron to titanium ratio of 2.1:1 (example 1), where the corresponding diffraction maxima are indicated.

In fig. Figure 3 shows an X-ray diffraction pattern of the resulting powder based on titanium diboride with a boron to titanium ratio of 2.5:1 (example 2) with the corresponding diffraction maxima indicated.

In fig. Figure 4 shows the X-ray diffraction pattern of the resulting powder based on titanium diboride at a boron to titanium ratio of 12:1 (example 3), where the corresponding diffraction maxima are indicated.

Table 1 presents the conditions for obtaining powders based on titanium diboride.

Powders of titanium Ti and X-ray amorphous boron with particle sizes of no more than 5 microns (with a purity of 99.0 wt.%) were used.

X-ray amorphous boron powder and titanium powder, taken in an atomic ratio in portions of 2.1:1; 2.5:1 and 12:1, weighing 1.5 g each, were placed in silicon nitride containers of a ball mill and mixed with silicon nitride balls for 20 minutes at a ratio of the mass of balls to the mass of powders as 3:1.

To implement the method, a device was used containing a graphite cathode (Fig. 1), consisting of a first graphite glass located vertically 1, in which a second graphite glass 2 is located coaxially. The outer diameter of the first graphite glass 1 is 30 mm, and the second graphite glass 2 is 20 mm. The second graphite glass 2 is covered with a graphite lid 3.

A dielectric holder 4 is attached to the wall of the first graphite glass 1, into the threaded hole of which a screw 5 is inserted, connected to the end of the graphite anode 6 in the form of a rod. The free end of the graphite anode 6 is located coaxially with the graphite glasses 1 and 2 with the possibility of longitudinal movement in the cavity of the first glass 1 until it comes into contact with the cover 3 of the second glass 2. The anode 6 is made in the form of a graphite rod

10 cm long and 8 mm in diameter. The anode 6 and the first graphite glass 1 are connected to a direct current source 7 (DCS).

A circle and a rectangle were previously cut out of 0.2 mm thick graphite paper with dimensions corresponding to the inner surface of the second glass 2.

These graphite paper blanks were placed inside the second graphite glass 2, completely covering its bottom and side surfaces.

1.5 g of the resulting mixture of boron and titanium powders was poured onto graphite paper. The second graphite glass 2 was placed inside the first graphite glass 1, coaxially with it. The second graphite glass 2 was covered with a graphite cover 3. After turning on the direct current source 7 (DCS), by rotating the screw 5, moved the anode 6 vertically down until it came into contact with the cover 3 and an electric arc discharge occurred at a current strength of 150 A. Heated the electric arc discharge on the mixture of boron powders and titanium for 20 s, then by rotating screw 5, anode 6 was retracted upward, thereby interrupting the combustion of the electric arc discharge. After this, the DC source 7 was turned off.

After the graphite glasses 1 and 2 cooled to room temperature, the second graphite glass 2 was removed from the first 1, the graphite lid was removed from the second graphite glass and the finished product in the form of a brown powder that had settled on the surface of the graphite paper was collected. The used graphite paper was disposed of.

The finished product was analyzed on a Shimadzu XRD 7000s X-ray diffractometer (CuKα radiation). The obtained X-ray diffraction patterns showed the presence of a hexagonal phase of titanium diboride, which corresponds to 8 diffraction maxima indicated in Fig. 2, fig. 3, fig. 4.

The initial data for examples of obtaining titanium diboride powder and the results of its analysis by X-ray diffractometry are given in Table 1.

METHOD FOR PRODUCING TITANIUM DIBOride POWDER

Table 1 No. Ratio of boron powder to titanium,
B:Ti Mass of initial titanium, g Mass of initial boron, g Mass of the resulting mixture, g Current, A Time, s Compound
product Product weight, g 1 2.1:1 1.018 0.482 1.5 150 20 TiB ₂ +Ti ₂ CN 1,496 2 2.5:1 0.959 0.541 1.5 150 20 TiB ₂ 1.256 3 12:1 0.404 1,096 1.5 150 20 TiB ₂ 0.915

Claims (1)

A method for producing titanium diboride powder, comprising use of X-ray amorphous boron powder and titanium powder with particle sizes of no more than 5 microns, taken in an atomic ratio (2.1-12):1, mixing them for 20 minutes at a ratio of the mass of ball mill balls to the total mass of powders 3:1, distribution the resulting mixture on the surface of graphite paper, previously laid inside a vertically located first graphite glass, which is covered with a graphite lid and coaxially placed inside a second graphite glass of a larger diameter, which is the cathode, an arc discharge is ignited in the air by contact of the anode in the form of a solid graphite rod with the upper surface of the graphite lids at a current of 150 A for 20 s, then remove the anode vertically upward, interrupting the combustion of the electric arc discharge, after cooling to room temperature, remove the graphite lid from the first graphite glass, remove the graphite paper from it and collect the finished product deposited on its surface, and used graphite paper is recycled.