In order to achieve low cost rapid surface modification of mechanical components a broad beam (10 cm. dia.), ultrahigh current density (up to 1500 μA/cm2) ion implanter has been developed at Colorado State University. The characteristics of ultrahigh current density ion implantation are compared to those of conventional ion implantation and the relative advantages of the ultrahigh current density implantation are identified. The temperature rise that typical implanted surfaces experience during implantation at various current densities are measured and compared with numerical heat transfer calculations. It is shown that even though the temperature rise can be high at ultrahigh current density implantation conditions, the times at temperature are sufficiently short (typically, 11 sec.) so that no significant tempering, annealing or other diffusion based transformations in the bulk material (i.e. beneath the implanted layer) are induced. The microstructure and hardness beneath the implanted layer are compared before and after ultrahigh current density ion implantation. The results on 1018 martensitic steel, 440C martensitic steel, 52100 martensitic steel, 304 stainless steel, Ti-6A1–4V and 2024-T3 aluminum are presented. The substantial advantage of much deeper (fourfold) ion penetration observed with ultrahigh current density implantation is identified. It is suggested that this increased depth of penetration is due to the phenomenon of radiation enhanced diffusion.