1. The lubricity of boron nitride

Boron nitride came out more than 100 years ago. The application polymorph is hexagonal boron nitride as a high-temperature lubricant, abbreviated as: h-BN, or a-BN, or g-BN (that is, graphite-type boron nitride), hexagonal nitride Boron is smooth, and the friction coefficient between powders is very low. Each layer of its atomic structure contains boron and nitrogen. There is no BN bonding between the layers, so the planes slide between each other to obtain a soft and lubricating effect. Very suitable for application as a high temperature release agent. Monomer boron

From the application occasion or the downstream product system of the application, there are generally the following types:

Various optical glass release agents

Mold release agent for metal forming and lubricant for metal wire drawing

Metallurgical separation ring used for continuous steel casting, etc.

2. Advantages of Boron Nitride Release Agent

Good lubricity: fine blending of various powders, strong and effective adhesion to the surface of the mold, forming a good lubrication effect.

Can prolong the life of the mold: effectively reduce mold loss and reduce the time required to clean the mold. During the glass process, the surface defects of the glass product can be reduced to make the glass easier to demold.

Good operability: spray formula, can be evenly coated on the surface of the mold using manual methods.

Fast drying speed: the quick-drying formula, fast drying speed, improve production efficiency and reduce.

Low friction coefficient: The friction coefficient u is 0.16, which does not increase at high temperature. Compared with molybdenum disulfide and graphite, the oxidizing atmosphere can be used up to 800°C, and it can be used up to 2000°C under vacuum.

Good corrosion resistance: with general metals (iron, copper, aluminum, lead, etc.), rare earth metals, precious metals, semiconductor materials (germanium, silicon, potassium arsenide), glass, molten salt (crystal stone, fluoride, slag ), inorganic acids and alkalis do not react.

Mechanical: Its Mohs hardness is 2, so it can be made into high-precision parts by general mechanical methods

Third, the application of boron nitride release agent in the release of glass molds

With the rapid development of industries such as our products, food and beverages, the demand for all kinds of packaging glass bottles and cans has increased. The determinant bottle making machine has become the mainstream model for glass bottle production and is widely used, and the running speed of the determinant bottle making machine is getting faster and faster, and the requirements for the lubricating release agent of the glass mold are getting higher and higher. The traditional method of lubricating and demolding glass molds uses manual application or mechanical spraying of animal and vegetable oils, which generally do not work well.

The use of boron nitride lubricating material significantly improves the lubrication and demoulding effect. At present, the most widely used boron nitride release agents are mainly divided into the following three categories:

One type uses water as the medium, adding high-temperature adhesives and other additives to make a water-based lubricant, which is applied to the surface of the mold at one time, and used after drying to form a film.

The other type uses oil as the medium and adds additives to make oily lubricants, which are continuously brushed or sprayed during the operation of the line-type bottle making machine.

A commonly used boron nitride release agent is to coat high-viscosity mineral oil with boron nitride and mix with water under the action of an emulsifier to make an emulsified oil type lubricating release agent for glass molds. When boron nitride: grease: water = 1:4:10, and the emulsifier dosage is 7wt%, the prepared emulsified oil release agent has good stability, good release performance, and has the characteristics of thin oil film and uniform distribution. The use of boron nitride lubricating mold release agent improves the yield of bottle making, reduces the consumption of lubricating mold release agent, and purifies the production environment.

Boron nitride release agent can also be applied to flat glass, which can greatly improve the working environment and product efficiency. The effect is more significant when used on curved glass:

Highly difficult deep bends, special shapes, hot melt, clear light, etc.

4. Application of Boron Nitride Release Agent in Metal Casting Melting and Welding

The chemical stability of hexagonal boron nitride can resist the neutron radiation of nuclear reactors, and neither acid nor alkali can affect it. In an inert atmosphere (nitrogen or argon), the decomposition temperature is 2500℃, and it exhibits excellent chemical stability under the conditions. Sex.

Hexagonal boron nitride can be made into boron nitride separation ring for horizontal continuous casting of steel. Hexagonal boron nitride is very stable to carbon and carbon monoxide at 1800°C, and it is not corroded by molten glass, silicon, boron, non-oxide slag, and molten salt (borax, cryolite) in steel.

Hexagonal boron nitride can be made into a composite shell for titanium casting. Titanium metal has poor chemical stability. When the forging is severely deformed at high temperature, the metal flow produces a fresh surface that is prone to sticking to the mold, causing the forging and the mold to be scrapped at the same time. The boron nitride release agent composite shell layer is coated on the surface of the mold to avoid direct contact between the titanium metal and the mold.

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