Experimental study on friction and wear behaviour of amorphous carbon coatings for mechanical seals in cryogenic environment

► The coefficient of friction of a-C coatings was in the range of 0.10 to 0.15 under cryogenic environment. ► The coatings had a graphite-like characteristic and were available to cryogenic environments. ► The deposition of the a-C coatings could significantly reduce the specific wear rate of seal rings. ► We explore the suitability of a-C coatings used in cryogenic mechanical seal.