Chromium carbide, especially chromium carbide powder, is a compound with unique physical and chemical properties. It is widely used in industry and materials science, and stands out for its high hardness, high melting point, good wear resistance and oxidation resistance.

Typically, it exists as Cr₃C₂ – a gray, metallic luster powder belonging to the orthorhombic crystal system. It has a density of 6.68 g/cm³, a melting point up to 1890℃, and a boiling point of 3800℃. At high temperatures (1000-1100℃), chromium carbide powder shows excellent wear resistance, corrosion resistance and oxidation resistance. Besides, its microhardness reaches 2700 kg/mm², with a thermal expansion coefficient of 11.7×10⁻⁶/℃. Chemically, it resists acids and alkalis well and is insoluble in water.

Currently, the main methods to produce chromium carbide powder include high-temperature solid-state reaction, chemical vapor deposition (CVD) and chemical vapor infiltration (CVI). First, high-temperature solid-state reaction is the most common method: mix chromium powder and carbon powder, then react them at high temperature to form chromium carbide powder. This method yields high-purity powder but consumes much energy.

Second, CVD uses chromium and carbon atoms in the gas phase to react at high temperature – it creates uniform, dense coatings, suitable for high-precision coating needs.

Third, CVI lets chromium and carbon atoms penetrate the matrix via chemical reactions, forming chromium carbide composites.

Additionally, there’s the slag method: place carbon-containing samples to be coated in slag of specific temperature and composition, then generate chromium carbide through multiphase reactions to deposit on the matrix surface. This approach is easy to operate, low-cost and low-pollution.

Thanks to its excellent properties, chromium carbide powder has wide applications.

 First, it makes wear-resistant and corrosion-resistant coatings. For example, via plasma spraying, it acts as a high-temperature, wear/oxidation/acid-resistant coating – widely used on aircraft engines and petrochemical machinery parts to extend service life. Second, it serves as a grain refiner for cemented carbides, making high-performance cutting tools.

Third, it sprays semiconductor films for the electronics industry. Fourth, Ni-Cr/chromium carbide composite powder aids metallurgy: thermal spraying with it boosts material wear and oxidation resistance.

In recent years, as materials science advances, research on chromium carbide powder has progressed significantly. For instance, researchers used first-principles and laser cladding to study chromium carbide-reinforced nickel-based coatings. They found chromium carbide has three main morphologies: quadrilateral (Cr₃C₂), hexagonal (Cr₇C₃), and irregular (eutectic of Cr₇C₃ and Cr₃C₂). Through in-situ formation, the reinforcement phase disperses in the coating, greatly improving microhardness and wear resistance.

Additionally, its use in composites gains attention – adding chromium carbide particles to coatings enhances material performance, and this composite has broad prospects in aerospace and automotive manufacturing.