Applied as a thin coating, TiN is used to harden and protect cutting and sliding surfaces, for decorative purposes (for its golden appearance), and as a non-toxic exterior for medical implants.

The typical TiN formation has a crystal structure of NaCl type with a roughly 1:1 stoichiometry; TiNx compounds with x ranging from 0.6 to 1.2 are, however, thermodynamically stable.

[12][13] A well-known use for TiN coating is for edge retention and corrosion resistance on machine tooling, such as drill bits and milling cutters, often improving their lifetime by a factor of three or more.

As a coating, it is used in aerospace and military applications and to protect the sliding surfaces of suspension forks of bicycles and motorcycles, as well as the shock shafts of radio-controlled cars.

Owing to their high biostability, TiN layers may also be used as electrodes in bioelectronic applications[20] like in intelligent implants or in-vivo biosensors that have to withstand the severe corrosion caused by body fluids.

[24] Its high Young's modulus (values between 450 and 590 GPa have been reported in the literature[25]) means that thick coatings tend to flake away, making them much less durable than thin ones.

Titanium-nitride coatings can also be deposited by thermal spraying whereas TiN powders are produced by nitridation of titanium with nitrogen or ammonia at 1200 °C.

[7] Bulk ceramic objects can be fabricated by packing powdered metallic titanium into the desired shape, compressing it to the proper density, then igniting it in an atmosphere of pure nitrogen.

These coatings offer similar or superior enhancements in corrosion resistance and hardness, and additional colors ranging from light gray to nearly black, to a dark, iridescent, bluish-purple, depending on the exact process of application.