Forming of the Ti6Al4V-60 %TiB2 metal-ceramic microcomponent under coupled multi-physical fields for improved microstructures and mechanical performances

Abstract

Abstract In the presented study, a coupled multi-physical fields activation forming method was utilized to form the Ti6Al4V/TiB2 metal ceramic microcomponent with 60wt% TiB2 powders and the effects of the processing parameters on the microstructure, densification and mechanical performance of the formed sample were studied. The result shows that a relative density, 96.43 %, of the formed sample is achieved when the case of temperature 1500°C, heating rate 30°C /s, pressure 125MPa and dwell time 1 min, is used. Microstructures of the formed sample suggest the forming process involves the formation of TiB nanocrystalline in the Ti matrix due to the chemical reaction between the TiB2 and Ti phases and the formations of the defects in TiB2 grains and the liquid phase of Ti. Many stacking faults, lattice distortion and vacancy defects are produced in the TiB2 grain owing to the particles’ deformation during the forming process. The liquid Ti phase is formed in some local areas due to the Joule heat generated by the current. The variation tendency of Vickers hardness is in accordance with that of relative density, which initially shows a significant increase and then decreases with the forming time and a peak hardness of 1690 HV is achieved.