Interlayer laser cladding SiC regulates microstructure and mechanical properties of Ti-6Al-4V arc-directed energy deposited components

Abstract

The existing methods for preparing titanium matrix composites (TMCs) are less efficient and more expensive. An interlayer laser cladding SiC during arc-directed energy deposition Ti-6Al-4V was developed to efficiently prepare the TMCs, whose microstructure and mechanical properties were analysed to explore the mechanism for change. TiC and Ti5Si3 precipitated at grain boundaries, hindering the growth of α-Ti and β-grains and reducing the size difference between different deposition heights. The fine grain strengthening produced by the reduction in the size of the α phase and the prior β columnar grains, as well as the precipitation strengthening produced by the formed ceramic phase, increased the microhardness of the LCS component by 21.1%. The ceramic phase and the disappearance of the α/β interface phase increased the brittleness of the LCS component, whose tensile properties were slightly decreased than the directed energy deposited (DED) components.