Hardness improvement of surface alloyed materials fabricated with Fe based metamorphic powders by high energy electron beam irradiation

Abstract

In the present study, surface alloyed materials were fabricated with Fe based metamorphic powders by the high energy electron beam irradiation. A surface alloyed layer was fabricated by depositing metamorphic powders on a carbon steel substrate and by irradiating with high energy electron beam. On top of this surface alloyed layer, metamorphic powders were deposited once again and irradiated with electron beam to fabricate a two layered surface alloyed material. In the surface alloyed layers, 53–64 vol.-%Cr_1·65Fe_0·35B_0·96 borides were densely precipitated in the martensitic matrix. A large amount of hard borides improved the hardness of the surface alloyed layers 2–3 times greater than that of the substrate. In addition, they showed high hardness of ∼500 VHN even at 450°C, because borides were thermally stable at high temperatures. These results suggested potentials of the fabricated surface alloyed materials for applications requiring good wear and thermal resistance.