Biomedical Ti-55.78 (wt%) Ni alloy samples were prepared by vacuum induction melting, and their hot compression deformation behavior was studied in the deformation temperature range of 750-950℃, the strain rate range of 0.001-1.000 s^-1 and the true strain range of 0.1 -0.7. The constitutive equation of the as-cast biomedical Ni-Ti alloy was established based on the Arrhenius constitutive model, and error analysis of the constitutive equation was carried out. The processing zone and unstable thermal deformation zone of the as-cast biomedical Ni-Ti alloy were obtained by establishing hot processing maps based on a dynamic material model. The results showed that deformation temperature and strain rate were the main factors affecting the flow stress. The results of error verification of the constitutive equation show that the predicted flow stress curves agree well with the measured ones. Therefore, the constitutive equation based on Arrhenius can accurately predict the high temperature flow stress of as-cast biomedical Ni-Ti alloy. The optimum parameters for forging process of biomedical Ni-Ti alloy are the strain rate less than 0.003 s^-1 and the hot deformation temperature range of 930-950℃.
A new silver(Ⅰ) compound 4 containing thiosemicarbazone with group 2-quinoline was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. Compound 4 crystallizes in triclinic, space group P1 with a = 12.2710(9), b = 16.9281(13), c = 17.2984(13), α = 112.8500(10), β = 103.4890(10), γ = 102.6860(10)°, V = 3020.9(4) 3, C80H94Ag6N28O6S6, Mr = 2383.41, Dc = 1.310 g/cm3, μ(MoKα) = 1.108 mm-1, F(000) = 1196, Z = 1, the final R = 0.0567 and wR = 0.1368 for 5112 observed reflections (I > 2σ(I)). Similar to the structure of compound 2 we have reported, compound 4 also exhibits a hexanuclear silver(Ⅰ) cluster. In the cluster, the S atom of ligand L4 (L4 = 2-quinolinecarboxaldehyde thiosemicarbazone) serves as a triply bridged chelator to connect the six silver atoms into a Ag6L46 cluster. The luminescence property of 4 is investigated at room temperature and compared with that of 2.
