EFFECTS OF IMPLANTATION TREATMENTS ON MICROMECHANICAL PROPERTIES OF M2 STEEL

This work reports on the use of a depth-sensing technique at loads bel ow 25.6 mN to evaluate properties of implanted M2 steel. Implantations were carried out on polished discs with N+, Cr+ + N+ and Cr+ ions at energies from 25 to 180 keV and total doses above 10(17) ions/cm2. Sin gle and multiple energy implants were carried out to evaluate the effe ct on mechanical properties of M2 steel by implantation with interstit ial and substitutional elements. Nitrogen implantation showed improvem ents on surface hardness up to about 50% and higher elastic recovery t han the substrate material. This can confirm the wear resistance resul ts already obtained on tool steels used in cold forming and the proces sing of reinforced, plastics. Combination of nitrogen and chromium ion s presented similar hardening effects even at greater depths, while im plantation of chromium showed only a very marginal improvement in hard ness, with limited effect on elastic recovery values. XPS data are als o presented to show the chemical effects of the implanted element rela ted to the benefit in properties obtained.