What is the difference between boron carbide and boron nitride?

What is the difference between boron carbide and boron nitride?
Boron carbide, also known as black diamond, has a molecular formula of B₄C and is usually a gray-black micropowder. It is one of the three hardest known materials (the other two are diamond, cubic boron nitride) and is used in tank armor, body armor and many industrial applications. It has a Mohs hardness of 9.3.
Boron carbide can absorb a large number of neutrons without forming any radioisotopes, so it is an ideal neutron absorber in nuclear power plants, and neutron absorbers mainly control the rate of nuclear fission. Boron carbide is mainly made into controllable rods in nuclear reactors, but sometimes it is made into powder to increase the surface area.
Because of its low density, high strength, high temperature stability and good chemical stability. It is used in wear-resistant materials, ceramic reinforced phases, especially in lightweight armor, reactor neutron absorbers, etc. In addition, compared with diamond and cubic boron nitride, boron carbide is easy to manufacture and low in cost, so it is more widely used. It can replace expensive diamond in some places and is commonly used in grinding, grinding, drilling, etc. applications.
Boron oxide, chemical formula: B2O3, also known as boron trioxide, is the most important oxide of boron. It is a white waxy solid that generally exists in an amorphous state and is difficult to form crystals, but can also crystallize after high-strength annealing. It is one of the most difficult substances known to crystallize. When melted, it can dissolve many alkaline metal oxides to generate glassy borate and metaborate (glass) with characteristic color, which is used to prepare elemental boron and fine boron compounds. It can also be combined with various oxides to make boron glass, optical glass, heat-resistant glass, instrument glass and glass fiber, light protection materials, etc. with characteristic colors. It can also be used as a fire-resistant olefin additive and desiccant for paints.