Nanocrystalline alloy wlth graln size of about 10～20nm was prepared by mechanlcal alloying of elemen- tal powders in an imnliscible Ta-Cu system, The structure changes of Ta_70Cu_30 during mechanical alloying were mo...Nanocrystalline alloy wlth graln size of about 10～20nm was prepared by mechanlcal alloying of elemen- tal powders in an imnliscible Ta-Cu system, The structure changes of Ta_70Cu_30 during mechanical alloying were monitored by X-ray diffraction. scanning electron microscopy and transmission electron microscopy. High-energy ball milling can efficiently reduce the grain size and considerably increase the Cu solubility in Ta. The significant enhancement of hardness of alloyed powders was also observed.展开更多
The effects of Ta on the characteristics of the Zr-base BMG (bulk metallic glass) were investigated. Zr55Al10Ni5Cu30-xTax (x=1, 2,4) bulk metallic glasses (BMGs) with 3.5 mm diameter and 70 mm length were successfully...The effects of Ta on the characteristics of the Zr-base BMG (bulk metallic glass) were investigated. Zr55Al10Ni5Cu30-xTax (x=1, 2,4) bulk metallic glasses (BMGs) with 3.5 mm diameter and 70 mm length were successfully prepared by using combined jet and copper mold casting. A small amount of Ta addition does not change the glass transition temperature, crystallization temperature, and supercooled liquid region obviously, but Ta promotes composition separation and two-stage crystallization. The stable crystalline phases include Zr2Ni, CuZr2, Al2Zr3 intermetallic compounds and Ta-rich solid solution after annealing the Zr-Al-Ni-Cu-Ta alloys at 753 K. Zr55Al10Ni5Cu30-xTax (x=1,2,4) bulk glassy alloys exhibit a better compressive strength. The stress-strain curve shows a zigzag feature, and the fracture surface shows intersecting of shear bands. It may correlate with the inhomogeneous feature of amorphous structure.展开更多
基金Postgraduate Innovation Programs of Jiangsu Scientific Research(CXLX11_0921)The Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
基金Major National Science and Technology Special Projects(2016ZX02301003-004-007)Natural Science Foundation of Hebei Province,China(E2014202147,F2015202267)Key Laboratory of Electronic Materials and Devices of Tianjin,China
文摘Nanocrystalline alloy wlth graln size of about 10～20nm was prepared by mechanlcal alloying of elemen- tal powders in an imnliscible Ta-Cu system, The structure changes of Ta_70Cu_30 during mechanical alloying were monitored by X-ray diffraction. scanning electron microscopy and transmission electron microscopy. High-energy ball milling can efficiently reduce the grain size and considerably increase the Cu solubility in Ta. The significant enhancement of hardness of alloyed powders was also observed.
基金This work was financially supported by the National Natural Science Foundation of China (No.50171005 and 50171006) the National Hi-tech Research and Development Program of China (No.2001AA331010) the National Major Basic Research Project of China (No.G2000 67201-3) the Major Science and Technology Program of Beijing (No.H020420030320).
文摘The effects of Ta on the characteristics of the Zr-base BMG (bulk metallic glass) were investigated. Zr55Al10Ni5Cu30-xTax (x=1, 2,4) bulk metallic glasses (BMGs) with 3.5 mm diameter and 70 mm length were successfully prepared by using combined jet and copper mold casting. A small amount of Ta addition does not change the glass transition temperature, crystallization temperature, and supercooled liquid region obviously, but Ta promotes composition separation and two-stage crystallization. The stable crystalline phases include Zr2Ni, CuZr2, Al2Zr3 intermetallic compounds and Ta-rich solid solution after annealing the Zr-Al-Ni-Cu-Ta alloys at 753 K. Zr55Al10Ni5Cu30-xTax (x=1,2,4) bulk glassy alloys exhibit a better compressive strength. The stress-strain curve shows a zigzag feature, and the fracture surface shows intersecting of shear bands. It may correlate with the inhomogeneous feature of amorphous structure.
