Improvement of Friction and Wear Resistance for Ta or Ta+C Implanted H21 Steel

Ta and C ions extracted from a metal vapor vacuum arc ion source were implanted into H21 steel, with an implantation dose of 3 x 10¹⁷cm^-2, extraction acceleration 42kV, and average ion beam flux about 40μA.cm^-2. Rutherford backscattering spectrum was used to measure the surface composition after Ta or Ta+C implantation. Observation of phase induced by Ta and C implantation was carried out by x-ray diffraction analysis. Experimental results showed that the wear rate of the implanted layer dropped 30% for Ta ion implantation and by a factor of 2.5 for Ta+C dual ion implantation. Thus Ta+C dual ion implantation was found to significantly reduce the friction coefficient of H21 steel. The wear mechanisms of the implanted layer were discussed.