Microstructures and Tensile Mechanical Properties of Titanium Rods Made by Powder Compact Extrusion of a Titanium Hydride Powder

Nearly fully dense titanium with good mechanical properties was fabricated rapidly by induction heating, holding, and hot extrusion of the TiH2 powder compacts. The dehydrogenation and consolidation processes took less than 15 minutes in total. The microstructures, contents of interstitial elements (H, O), tensile mechanical properties, and fracture behaviors of titanium samples made with different holding and extrusion temperatures [1273 K, 1373 K, and 1473 K (1000 A degrees C, 1100 A degrees C, and 1200 A degrees C)] were investigated. The results showed that the hydrogen content in the extruded rods was around 0.09 wt pct when the holding and extrusion temperature was 1373 K or 1473 K (1100 A degrees C or 1200 A degrees C), with almost all of the TiH2 phase being transformed into Ti phase during the heating, holding, and extrusion process steps. The extruded Ti samples had a lamellar structure consisting of fine alpha lamellae with random orientations in different lamellar colonies and the relative density of all the extruded samples exceeded 99.5 pct. The residual TiH2 phase can reduce the ductility of extruded rods. The sample extruded at 1373 K (1100 A degrees C) has the best elongation to fracture of 21.0 pct, and its average yield strength and ultimate tensile strength reached 536.8 and 691.8 MPa, respectively.