Surface alloying of Cr on Ti6Al4V alloy induced by high-current pulse electron beam

摘要

In current investigation, an alloying treatment of Cr on Ti6Al4V surface was successfully materialized through a high-current pulsed electron beam (HCPEB) irradiation with different number of pulses. For characterizing the evolutions of the phase and microstructure, X-ray diffraction, optical microscopy, scanning electron microscopy and transmission electron microscopy were adopted, and the results showed that, after HCPEB irradiation, a Cr-alloyed layer was formed on the irradiated surface, which layer thickened as the number of pulse increased. In addition, within the alloying layer, the martensitic transformation occurred, and alpha' martensite laths and equiaxed beta grains were formed. Moreover, evenly distributed Cr2Ti particles (Laves phase) were observed in the Cr-alloyed layer, and the forming mechanism of this Laves phase was also discussed. Properties, including surface microhardness, wear resistance and corrosion resistance, were evidently improved after the surface alloying treatment induced by HCPEB, and the relevant mechanisms were also analyzed.