Product Name: Chromium Diboride (CrB2) 
Specification: 0.8-10um (D50) 
Appearance: Irregular 
Color: Black Grey 
Features: high melting point, high hardness, excellent wear resistance, high temperature resistance, corrosion resistance, thermal conductivity 
Usage: Sputtering targets, wear-resistant components, fire-resistant materials and other fields

Product Name: Chromium Diboride 
Chromium diboride: B2Cr 
English name: Chromium boride (CrB2) 
EINECS：234-499-3 
Density: 5.6g/mL 
Flash point: Melting point: 1550 ℃ 
CAS:12006-80-3 
Molecular weight: 112.9969 
Property: Insoluble in water, soluble in molten sodium peroxide 
Usage: Used as wear-resistant, high-temperature oxidation resistant coating and neutron absorption coating in nuclear reactors. Used for ceramics, melt blown on metal and ceramic surfaces to form wear-resistant and corrosion-resistant films. Used for spraying semiconductor films. Chromium boride and aluminum oxide sintered or hot pressed products in a micro oxidizing atmosphere have practical value in high-temperature wear resistance. 
Synthesis method: 
Pure metal process: Chromium and an appropriate amount of boron powder are heated in a vacuum or inert atmosphere at 1600 ℃ or sintered at 1150 ℃ for 48-72 hours, forming borides such as CrB, Cr2B, Cr3B2, Cr3B4, and CrB2. After hot pressing at high temperatures, CrB2, CrB, or Cr3B4 can be formed. 
Chromium diboride (CrB2) coating has high melting point, high hardness, high wear resistance, and corrosion resistance. In addition, it has good chemical inertness and is not easy to bond with metals. As a hard protective coating, it is expected to meet these special chip processing requirements. 
This paper is mainly based on the research progress of CrB2 coatings and the development trend of hard coatings at home and abroad. The focus is on the preparation, structure, and properties of CrB2 coatings deposited by composite PVD technology. The research results have important scientific significance and application value. 
This article first uses high-power pulsed magnetron sputtering deposition technology (HiPIMS) to deposit CrB2 coating, characterizes the composition, phase structure, and mechanical properties of the coating, and focuses on studying the friction and wear behavior of the coating under different testing environments (dry friction, distilled water, and seawater environment). The results showed that the CrB2 coating exhibited a (101) preferred orientation, with the main phase structure composed of CrB2 and a small amount of Cr. The atomic ratio of B/Cr in the coating was 1.76, and the hardness and elastic modulus were 26.9 ± 1.0 GPa and 306.7 ± 6.0 GPa, respectively. The friction coefficients of the coating in dry friction, distilled water, and seawater environments are 0.75, 0.26, and 0.22, respectively. When the coating rubs in distilled water and seawater environments, the friction coefficients are significantly reduced due to the boundary lubrication effect of distilled water and seawater. The friction and wear mechanism in dry friction and distilled water environment is abrasive wear, while in seawater environment, it is a synergistic effect of corrosion wear and abrasive wear. Secondly, as a comparison with HiPIMS technology, direct current magnetron sputtering technology was used to obtain a coating with a chemical stoichiometric ratio close to CrB2 by adjusting the target substrate distance. As the deposition temperature changed, the B/Cr atomic ratio was between 1.9 and 2.0. XPS results showed that the coating was still mainly composed of CrB2 and a small amount of Cr, with a relatively small roughness and Rq between 1.11 and 1.95 nm; As the deposition temperature increases, the diffusion ability of adsorbed atoms on the substrate surface increases, and the crystallinity of the coating gradually increases. The crystal structure changes from a mixed orientation of (101) and (001) to a preferred orientation of (001); The cross-sectional morphology of the coating changes from a loose and porous fibrous structure to a coarse columnar structure (with a diameter of about 50 nm), and finally to a dense nano columnar structure (with a diameter of about 4-7 nm). With the increase of deposition temperature, the mechanical properties of the coating are significantly improved. When the deposition temperature is above 300 ℃, a superhard CrB2 coating with a hardness greater than 40 GPa can be obtained. When the deposition temperature is 400 ℃, the hardness of the coating can reach as high as 50.7 ± 2 GPa. The evolution of microstructure and mechanical properties with deposition temperature is attributed to the (001) preferred orientation and densification of the microstructure resulting from the increasing diffusion motion of deposition atoms. Finally, this article also investigated the thermal stability of CrB2 coatings with (101) and (001) preferred orientations, and tested the basic electrochemical properties of CrB2 coatings on hard alloy substrates and at different deposition temperatures in 3.5 wt.% NaCl solutions. Research has shown that (101) preferentially oriented CrB2 coatings generate new phases at 1000 ℃, while (001) preferentially oriented CrB2 coatings do not undergo significant phase decomposition and transformation at 1000 ℃ and below, exhibiting higher high-temperature stability. This is attributed to the higher surface energy and lattice distortion energy of (101) preferentially oriented CrB2 coatings, which have lower phase transition activation energy; Although the corrosion potential of CrB2 coating is higher than that of cemented carbide, the corrosion current density is reduced by nearly two orders of magnitude, indicating that CrB2 coating can effectively protect cemented carbide in corrosive media containing Cl-1.