What is boron carbide B4C? What is the preparation method?

Boron carbide preparation

Boron carbide was first reported in the Journal of the American Chemical Society. It was obtained through the reaction of coke and boron oxide in an electric furnace. This preparation method is also the method currently used in industrial production.

2B2O3+7C=B4C+6CO

Physical and chemical properties of boron carbide

It does not react with acid and alkali solutions, and has high chemical potential, neutron absorption, wear resistance and semiconductor conductivity. It is one of the most stable substances to acid, stable in all concentrated or dilute acid or alkali aqueous solutions. Boron carbide is basically stable below 800°C in an air environment. The boron oxide formed by its oxidation at a higher temperature is lost in the gas phase, leading to its instability and oxidation to form carbon dioxide and boron trioxide.

Boron carbide has special stability when some transition metals and their carbides coexist. The transition metals of groups IV, V and VI in the periodic table of the elements react strongly with boron carbide powder to form metal borides at 1000-1100°C. However, at higher reaction temperatures, literature reports indicate that boron carbide is easily nitridated or reacts with transition metal oxides to form corresponding boron nitrides and borides. The borides are rare earth and alkaline earth metal hexaborides. many.

When sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate are melted, boron carbide is easily decomposed, and the boron content is measured.

Its Mohs hardness is about 9.5, which is the third hardest substance known after diamond and cubic boron nitride, and its hardness is higher than that of silicon carbide.

Due to the factors of preparation methods, boron carbide is prone to form carbon defects, causing the boron-to-carbon ratio to vary in a large range without affecting its crystal structure, which often leads to a decrease in its physical and chemical properties. Such defects are often difficult to distinguish by powder diffraction, and often require chemical titration and energy loss spectroscopy to determine.

It should be noted that in addition to B4C, boron carbide materials may have different stoichiometric ratios. The currently known B:C stoichiometric ratio is 4 to 10.5.

Overview of boron carbide B4C powder

Boron carbide has the characteristics of low density, high strength, good high temperature stability, and good chemical stability. Therefore, it is widely used in wear-resistant materials, ceramic reinforcement phases, especially lightweight armor, reactor neutron absorbers, etc. In addition, compared with diamond and cubic boron nitride, boron carbide is easy to manufacture and low in cost, so it is more widely used. In some places, it can replace expensive diamonds, usually used for polishing, grinding, drilling, etc.

B4C powder has the characteristics of high purity, small particle size distribution, and large specific surface area. B4C powder is a synthetic superhard material with a hardness of 9.46; a microhardness of 56-6200Kg/mm2, a ratio of 252g/cm3, and a melting point of 2250 degrees Celsius.

Chemical characteristics, non-magnetic, high temperature and low temperature resistance, strong acid, strong alkali. In addition, boron carbide can effectively absorb neutrons, does not emit gamma rays harmful to the human body, and does not form secondary radiation pollution. The hardness is only lower than diamond. Boron carbide is one of the most stable substances to acid, and it is stable in all concentrated or dilute acid or alkali aqueous solutions. Boron carbide is basically stable below 800°C in an air environment. The boron oxide formed by high temperature oxidation is lost in the gas phase, making it unstable and oxidized to form carbon dioxide and boron trioxide.

Boron carbide can absorb a large number of neutrons without forming any radioactive isotopes. It is an ideal neutron absorber for nuclear power plants. Neutron absorbers mainly control the rate of nuclear fission. Boron carbide is used in nuclear reactors. Made into controllable rods, but sometimes made into powder due to increased surface area.

Application of boron carbide B4C powder

Control nuclear fission: can absorb a large number of neutrons without forming any radioactive isotopes. It is an ideal neutron absorber for nuclear power plants. Neutron absorbers mainly control the rate of nuclear fission. Boron is mainly made into controllable rods in the field of nuclear reactors, but sometimes it is made into powder due to the increase in surface area.

Abrasive: Because boron carbide has been used as a coarse abrasive for a long time. Because of its high melting point, it is not easy to cast into artificial products, but the powder can be smelted into simple shapes. high temperature. Used for grinding, grinding, drilling and polishing hard materials such as cemented carbide and gems.

Coating paint: Boron carbide can also be used as a ceramic coating for warships and helicopters. It is light in weight and can resist the penetration of armor-piercing projectiles through the hot-press coating to form an overall defense layer.

Nozzle: Boron carbide can be used as a spray gun nozzle in the ordnance industry. Boron carbide is extremely hard and wear-resistant, does not react with acid and alkali, is resistant to high temperature/low temperature, and is resistant to high pressure. Boron carbide is also used to make metal borides and smelt sodium-boron, boron alloys and special welding.

Price of boron carbide B4C powder

The price of boron carbide varies randomly with factors such as production costs, transportation costs, international conditions, exchange rates, and market supply and demand. Tanki New Materials Co., Ltd. aims to help various industries and chemical wholesalers find high-quality, low-cost nanomaterials and chemicals by providing a full set of customized services. If you are looking for boron carbide, please feel free to contact us for the latest boron carbide prices.

Supplier of Boron Carbide B4C Powder:

As a global boron carbide supplier, Tanki New Materials Co., Ltd. has extensive experience in the performance, application and cost-effective manufacturing of advanced engineering materials. The company has successfully developed a series of powder materials (including chromium carbide, aluminum carbide, titanium carbide, etc.), high-purity targets, functional ceramics and structural devices, and provides OEM services.