Creep rupture property of in situ synthesized (TiB + La2O3)/Ti composite

(TiB + La2O3)/Ti composite was synthesized in a consumable vacuum arc remelting furnace by a novel in situ technique based on the reaction between Ti, LaB6, and oxygen in the raw materials. The phases were identified by X-ray diffraction. The microstructures were examined by means of optical microscopy and scanning electron microscopy. TiB whiskers and nano-sized La2O3 spherical particles were distributed uniformly in the matrix. Creep rupture properties of the composite were tested at 873, 923 and 973 K. The results showed the creep rupture life of the composite increased significantly at elevated temperature while keeping good plasticity. The creep rupture life even exceeded the best elevated titanium alloy IMI 834. The improvement of creep rupture life and plasticity were mainly attributed to undertaking load by TiB whiskers, dispersion strengthening by nano-sized La2O3 particles and decrease of the oxygen content in the matrix by the addition of the LaB6.