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The optical absorption and fluorescence of Pr 3ϩ ions in yttria-stabilized zirconia single crystals are investigated. Fluorescence emissions from the 1 D 2 level are clearly dominant and low intensity emission lines from the 3 P 0 and 1 G 4 states are also observed. Analysis with the Judd-Ofelt theory of the absorption intensities has been made assuming that only ϳ40% of the praseodymium ions contribute to the optical absorption bands.Quantum efficiency values of ( 3 P 0 )ϳ0.2 and ( 1 D 2 )ϳ 1 are obtained at room temperature. 1 D 2 fluorescence quenching has been observed in heavily-doped samples due to cross relaxation processes among neighboring Pr 3ϩ ions. Analysis using the Inokuti-Hirayama model shows that electric dipole-dipole interactions are mainly responsible for the quenching effect. Pr 3ϩ ions are present in seven and sixfold configurations with a statistical distribution. The energy position of the 4 f 5d configuration is very different for each center. The fluorescence dynamics is explained by a mechanism involving thermally assisted population of the 3 P 1,2 ϩ 1 I 6 upper levels and fast relaxation to the 1 D 2 level via states of the excited 4 f 5d configuration.

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W and W V alloys reinforced with La 2 O 3 particles have been produced by MA and subsequent HIP at 1573 K and 195 MPa. The microstructure of the consolidated alloys has been characterized by scanning electron microscopy, energy dispersive spectroscopy analyses and X ray diffraction. The mechanical properties were studied by nanoindentation measurements. The results show that practically full dense billets of W V, W V La 2 O 3 and W La 2 O 3 alloys can be produced. The microstructure analysis has shown that islands of V are present in W V and W V 1La 2 O 3 alloys. In W 1La 2 O 3 islands of La 2 O 3 are also pres ent. The nanohardness of the W matrix increases with the addition of V, while decreases with the addi tion of La 2 O 3 .

Titanium Hydrostatic extrusion Texture Uni-axial deformation behavior Bi-axial deformation behavior Anisotropy Coarse-grained commercially pure (CP) Titanium is subjected to hydrostatic extrusion resulting in the formation of ultrafine lamellar-type microstructure having very strong fiber texture. Uni-axial tensile tests of longitudinal and transverse specimens are carried out to study anisotropy of uni-axial deformation behavior of hydrostatically extruded CP Titanium. Small punch testing of longitudinal and transverse specimens is performed to study the anisotropy of its bi-axial deformation behavior. It is demonstrated that there is significant anisotropy of both uni-axial and bi-axial deformation of CP Titanium after hydrostatic extrusion which is related to the specific microstructure and texture developed in the material during hydrostatic extrusion.