Tanyun Logo

LocationHome » » News&FAQ » Chemical Study » Application of boron nitride in release agent for high temperature mold

Application of boron nitride in release agent for high temperature mold

Boron nitride came out more than 100 years ago. The hexagonal boron nitride with polyhedron as a high temperature lubricant, in short: h-BN, or a-bn, or g-bn (graphite boron nitride). The hexagonal boron nitride is absolutely smooth and the coefficient of friction between powders is very low. Each layer of its atomic structure contains boron and nitrogen, and there is no BN bond between each layer, so the plane slides between each other, providing softness. The soft and lubricating effect is very suitable for applying a high temperature release agent.

What are the advantages of using boron nitride as a release agent?

Good lubrication: mixing special fine powder, strong and effective adhesion to the mold surface, creating an excellent lubricating effect.

It can extend the life of the mold: it can effectively reduce the mold loss and the time it takes to clean the mold. During glass processing, it can reduce the surface defects of the glass products to make the glass easier to demould.

Easy to operate: the special spray formula can be applied manually on the surface of the mold.

High temperature resistance: excellent thermal shock resistance, even if heated quickly and repeatedly cooled to 1500 1500, it will not crack even if heated to 2200 ℃, it can still be used safely.

High drying speed: special fast drying formula, high drying speed, improving production efficiency and lower cost.

Low coefficient of friction: the coefficient of friction u is only 0.16, which does not increase at high temperature. It is more resistant to high temperatures than molybdenum disulfide and graphite. The oxidation atmosphere can reach 2000 2000 and 2000 in in vacuum.

Good corrosion resistance: no reaction with general metals (iron, copper, aluminum, lead, etc.), rare earths, precious metals, semiconductor materials (germanium, silicon, potassium arsenide), glass, molten salt (crystal, fluoride, slag), inorganic acid and alkali, etc.

Machinability: The Mohs hardness is 2, so it can be machined into parts with general precision.

Application of boron nitride release agent in glass mold release

With the rapid development of alcohol, food, beverage and other industries in China, the demand for all types of glass bottles and cans is increasing. The determining bottle making machine has become the main model of glass bottle manufacturing and is widely used, and the operating speed of the determining bottle making machine is faster and faster, and the requirements for lubricating the glass mold release agent are increasing. The traditional method of glass mold lubrication and demoulding adopts manual coating or mechanical spraying of animal and vegetable fat, and the overall effect is not good.

The use of boron nitride lubricant material significantly improves the effect of deformation lubrication. Currently, widely used boron nitride delivery agents are divided into the following three categories:

One is to use water as a medium, add high temperature glue and other additives to make water based lubricant, brush it once on the mold surface and use it after drying and film forming.

The other is to use oil as a medium, add additives, make oil lubricant, and brush or spray continuously in the operation of the defining bottle making machine.

A commonly used boron nitride release agent is the coating of high viscosity mineral oil with boron nitride and the mixing of water under the action of an emulsifier to make an emulsified oil type lubricant dispenser. When boron nitride: oil: water = 1: 4: 10 and the amount of the emulsifier is 7% by weight, the emulsified oil demoulding agent has good stability, demoulding performance, thin oil film and uniform distribution. The use of boron nitride lubricant improves bottle making yield, reduces lubricant consumption and purifies the production environment.

Boron nitride release agent can also be applied in sheet glass processing, which can greatly improve the working environment and product efficiency. Especially for bending glass machining, the effect is more significant: high difficulty deep bending, special shape, heat melting, light removal, etc.

Application of boron nitride release agent in metal casting melting and welding

Hexagonal boron nitride has excellent chemical stability, which is resistant to neutron radiation from the nuclear reactor and cannot be affected by acid and alkali. In an inert atmosphere (nitrogen or argon), the decomposition temperature is as high as 2500 ° C, which shows excellent chemical stability under extreme conditions.

Hexagonal boron nitride can be converted into boron nitride separating ring for horizontal continuous casting of steel. Hexagonal boron nitride is very stable to carbon and carbon monoxide at 1800 ° C and is unaffected by molten glass, silicon, boron, non-oxide slag and molten salt (borax and cryolite) in steel.

A composite shell for casting titanium can be made from hexagonal boron nitride. The chemical stability of titanium is poor. When the forging deforms violently at high temperature, the fresh surface is produced by easily sticking metal flow to the die, resulting in the forging scrap and die at the same time. The composite shell coating of boron nitride release agent can prevent the direct contact between titanium metal and mold.

Hexagonal boron nitride can also be used in the welding and furnace brazing process, which can protect the surface of the workpiece from damage from welding spatter and also play a protective role in metal welding.

Recommended Article