The HSS samples were implanted with 3×10`17cm-2 of 60keV C ions and (2-6) 10`17cm-2 of 102keV Co ions respectively

from a MEVVA ion source.The average beam flux was about 26.5 A. cm-2 The surface friction coefficient and hardness were measured

and wearing test was made. It was shown that the surface hardness of C

Co or C+Co implanted HSS increased from 15% to 50%

and the C+Co dual implanted surface of HSS was the hardest.The surface friction coefficient of HSS implanted with Co or C+Co ions decreased from 0.42 to 0.14. The wear resistance of the surface modified by C+Co dual implantation was better than that modified by C or Co single implantation. The surface of HSS implanted with Co ions had better lubricity

elasticity and tenacity. The C+Co dual implantation was one of the best methods to improve the surface wear resistance of HSS.