Preparation And Properties Of Zr-based Bulk Metallic Glass And Composites

This paper mainly studied the following aspects. First studied the amorphous forming ability and the performance of Zr-Ni-Cu system alloys which is near the eutectic point and the effect of the added Al and Ti elements on the Zr-based amorphous forming ability and mechanical properties.The work also studied the influence of Cooling rate on mechanical properties of Zr-based bulk metallic glasses. Zr67Nil8Cul5,Zr63Ni20Cu17,Zr60Ni21Cu19,Zr56Ni22Cu22,(Zro.67Nio.1sCuo.15) ioo-xAlx (x=(0,2,,6,8,10) and (Zr0.603Ni0.162Cu0.135Al0.10) ioo-xTix (x=0,1,3,5) amorphous alloy were prepared by suction-casting process with copper mold and the diameter is 3mm. The stepped samples of (Zro.67Nio.1sCuo.15 ) ioo-xAlx ( x=8,10 ) and (Zr0.603Ni0.162Cu0.135Al0.10) ioo-xTix(x=l,3,5)amorphous alloy by the same ways, and the least diameter is 3mm and biggest diameter is 6mm, and the diameter of the middle section is 4mm. Fracture surface were examined by the X-ray diffraction (XRD). Compression tests were conducted on the cylindrical specimens at room temperature using universal testing machine. The appearance of the strained sample was examined using scanning electron microscopy (SEM).The hardness were examined by Vickers hardness tester and the polarization curve were tested by electrochemical workstation.Research shows that, for the Zr-Ni-Cu system alloys, Zr67Ni18Cu15 were crystal materials and the other were amorphous composite materisls.And when the content of Zr was reduced, Ni and Cu were rised thr compression fracture strength and corrosion reistance were enhanced.For the (Zro.67Nio.18Cuo.15) 1oo-xAlx (x =0,2,4,6,8,10) alloys, when x=10 the alloy was pure amorphous structure,but the other alloys were crystal materials or amorphous composite materisls.When x=10 the mechanical properties and hardness relatively high.And the rupture strength reached 1775MPa,plastic deformation reached 2.02% and hardness reached 781HV.For the (Zr0.603Ni0.162Cu0.135Al0.10) ioo-xTix (x=0,1,3,5) alloys when the x=5 the alloy was pure amorphous structure and its diameter is 3mm.Its rupture strength reached 1790 MPa while when x=3 the plastic deformation of alloy were up to highest of 2.91%. Electrochemical corrosion tested for the Zro.6O3Nio.l62Cuo.l35Alo.lo)loo-xTix(x=O,1,3,5)alloys ,results indicated that along with the increase of the content of Ti elements the corrosion resistance reduced and then increased.By XRD analysis,Compression test at room temperature and Microhardness analysis of Ladder-type specimens with different diameters.The results shows that Al element content of 10% and Ti element content of 5% the alloys were Amorphous alloy and the diameter is 3mm. While the diameter of 4mm and 6mm the alloys were amorphous composite materisls.The compressive fracture strength and hardness reduced with the diameter increase. The mechanical properties is little difference when the diameters between 3mm and 4mm, while when the diameter is 6mm whose mechanical properties is obviously lower than the diameter is 4mm.So we can see the mechanical properties of materials greatly influenced by the cooling rates.