Effect of Textures on Tensile Properties of Extruded Ti64/VGCF Composite by Powder Metallurgy Route

Monolithic Ti-6Al-4V and Ti-6Al-4V composited with vapor grown carbon fibers (VGCFs) were fabricated by powder metallurgy (P/M) route in this research. Spark plasma sintering (SPS) subsequent by hot extrusion was applied in order to fabricate a full-density and high strength composite materials. A severe plastic deformation during hot extrusion resulted in a dynamic recrystallization (DRX) in α-Ti grains. Dynamic recrystallization was observed in a low deformation temperature region, which yield point of material was also observed in the stress-strain curve. Furthermore, the addition of VGCFs encouraged the dynamic recrystallization during hot extrusion. Ti64+0.4 wt-% VGCFs shows the highest tensile strength of 1192 MPa at the end part of the extruded rod where the temperature of material was lower compared to the tip and middle part during extrusion. Additionally, the improvement in tensile strength was contributed by solid-solution strengthening of carbon element originated from VGCFs in α-Ti matrix.