Preparation, Microstructure And Properties Of Dispersive Nano-oxide Reinforced Cu-3Ti Alloy

The nanometer oxide reinforced Cu-3Ti alloy powders were prepared by mechanical alloying, in which the nano-sized Y2O3 and CuO were used as oxygen carrying agents. The oxide dispersion reinforced Cu-3Ti alloy was prepared by hot pressing at 1000? for 2h and aging treatment at differenent temperatures for 4h. The microstructures and phase constituents were characterized by optical microscope (OM), scanning electron rmicroscope (SEM), X-ray diffractometer (XRD) and transmission electron microscope (TEM), and the hardness, electrical conductivity and elastic modulus were measured as well. The following conclusions can be obtained from above investigations.(1) With increase of milling time, the particle size of alloying powders increases and then decreases. The average particle size reaches up to 5?m after milling for 60-72h.(2) With increase of milling time, Y2O3 particles are gradually fractured, Y2O3 nanocrystalline and Y-Ti-O clusters are formed after ball milling.(3) The microstructure of nanometer oxide reinforced Cu-3Ti alloy consists of high density of non-stoichiometric Y-Ti-O clusters, Y2Ti2O7, titanium oxides (Ti02, Ti509) and Cu2Y2O5.(4) After hot press sintering at 1000? for 2h, the hardness, electrical conductivity and elastic modulus of the nano-oxide reinforced Cu-3Ti alloy with 2.0wt%Y2O3 addition are 245HV, 49.21%IACS and 142.68GPa, respectively. After ageing at 450? for 4h,?-Cu3Ti phase generate in the Cu matrix. In the range of experiments, ageing parameters for Cu-3Ti alloy with the addition of 2.0wt%Y2O3 is at 450? holding for 4h,and the electrical conductivity and hardness are 52.41%IACS and 244HV, respectively.(5) The Cu-3Ti alloy with 1.5wt%YH2 addition has the larrgest electrical conductivity and hardness, which are 49.17%IACS and 230HV, respectively, and the elastic modulus is 143.05GPa. In the range of experiments,ageing parameters for Cu-3Ti alloy with 1.5wt%YH2 addition is at 450? holding for 4h,and the electrical conductivity and hardness are 51.9%IACS and 262HV, respectively.