Anyone in the high-temperature coatings industry knows there are two things to fear most: first, that the coating won’t withstand the heat, and second, that the material will “stick” to molten metal. Hexagonal boron nitride powder, however, solves both of these problems.

First, let’s discuss why it can withstand high temperatures. Hexagonal boron nitride can withstand temperatures of 900 to 1,000°C in air for extended periods, and in an inert atmosphere, it remains rock-solid even at temperatures above 3,000°C. What does that mean? Ordinary coatings would have burned away long ago, but it’s still sitting there just fine.

Now, let’s discuss why it doesn’t stick. Its crystal structure is very similar to graphite—layered, with interlayer bonds held together by van der Waals forces—making it non-wetting to molten metals, glass, and ceramics alike. When molten aluminum at 700°C or higher is poured onto it, the coating surface remains spotless, and demolding is exceptionally smooth. Here are the actual figures: After applying hexagonal boron nitride coating to aluminum casting molds, mold life is extended by more than three times, and the defect rate on castings is reduced by 60%. When used in glass furnace flow channels, melt residue is reduced by 85%, and equipment maintenance frequency drops from once a week to once a month.

Its lubricity is also exceptional. The coefficient of friction ranges from just 0.16 to 0.25 and does not increase at high temperatures. Unlike traditional lubricants such as molybdenum disulfide and graphite, which fail at high temperatures, it can even be used at 2000°C in a vacuum environment.

There is another point that many people overlook: it is both insulating and thermally conductive. With a breakdown strength of 30 to 40 kV/mm—twice that of aluminum oxide—and a thermal conductivity of up to 300 W/(m·K), it is used in electronic heat dissipation coatings to reduce thermal resistance by 40% and keep equipment temperatures consistently below 65°C. This technology is already in use in heat sinks for 5G base stations.

In the metallurgical industry, it is applied to submerged nozzles for molten steel and continuous casting protective sleeves to prevent sticking and resist corrosion, resulting in more stable metal flow. In ceramic sintering, it acts as a barrier between the sintered body and the sintering tray, preventing adhesion and contamination, and significantly improving yield rates. When used in aircraft engine components, it completely resolves the issue of titanium alloy sticking to crucibles, raising the product pass rate from 72% to 98%.

Currently, hexagonal boron nitride powder on the market can achieve a purity of over 99.5%, with particle sizes precisely controlled between 4 and 12 microns. When formulated into water-based coatings, it is environmentally friendly with no volatile emissions, and its adhesion has been improved by 50%.

Simply put, hexagonal boron nitride powder is the all-around performer in high-temperature coatings—it is “heat-resistant, non-stick, lubricating, and insulating.” It can single-handedly tackle the majority of the long-standing challenges in high-temperature industries, such as mold sticking, ablation, and oxidation.