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Qiu Y.,Control Iron and Steel Research Institute, China | Qiu Y.,Advanced Technology and Materials Co. | Zhang S.,Nanyang Technological University | Lee J.-W.,Ming Chi University of Technology | And 3 more authors.
Applied Surface Science

Vanadium nitride (VN) is easily oxidized to form vanadium oxides and becomes lubricious under stress. CrAlN is hard thus CrAlN/VN multilayer coatings render both hardness and lubricious properties attractive in dry machining of soft metals. This study investigates the effect of multi-layering on the coating's mechanical and tribological properties at room temperature. The CrAlN/VN multilayer coatings are deposited on cemented tungsten carbide and Si wafer (1 0 0) substrates in an in-line magnetron sputtering system. A period contains one layer of CrAlN plus one adjacent layer of VN. The period thickness varies roughly from 3 nm to 30 nm; the total number of the periods varies from 30 to 300. X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and electron probe micro-analyzer are employed to characterize the microstructures and chemistry. Nanoindentation and ball-on-disk wear test are used in mechanical and tribological studies. The CrAlN/VN multilayer coatings have good lubricant property with lowest coefficient of friction of 0.26. At the period thickness of 20 nm, the multilayer coatings obtained the best mechanical properties (hardness of 32.4 GPa, elastic modulus of 375 GPa, minimum wear rate of 1.1 × 10-7 mm3/Nm). © 2013 Published by Elsevier B.V. Source

Lv W.,Advanced Technology and Materials Co.
Materials Science Forum

The morphology, microstructure and magnetic properties in 1K107 alloy annealed bynitrogen and transversal magnetic (N2) are studied. The results show that coercivity(Hc), remanenceratio(Br/Bs), core loss(Pc), and effective permeability(μe) are efficiently optimized by transversalmagnetic annealing(N2) according to the methods of digital electric bridge, rectifier bridge, X-raydiffraction(XRD), and field emission scanning electron microscopy(FESEM), etc. © (2013) Trans Tech Publications, Switzerland. Source

Xu Z.-W.,University of Science and Technology Beijing | Jia C.-C.,University of Science and Technology Beijing | Kuang C.-J.,Advanced Technology and Materials Co. | Qu X.-H.,University of Science and Technology Beijing
International Journal of Minerals, Metallurgy and Materials

High-nitrogen nickel-free stainless steels were fabricated by the metal injection molding technique using high nitrogen alloying powders and a mixture of three polymers as binders. Mixtures of metal powders and binders with various proportions were also investigated, and an optimum powder loading capacity was determined as 64vol%. Intact injection molded compacts were successfully obtained by regulating the processing parameters. The debinding process for molded compacts was optimized with a combination of thermo-gravimetric analysis and differential scanning calorimetry analysis. An optimum relative density and nitrogen content of the specimens are obtained at 1360°C, which are 97.8% and 0.79wt%, respectively. © University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg 2010. Source

Recent advance and application about Fe-based amorphous nanocrystalline alloy have been reviewed, the latest achievement of static stress annealing, continuous moving stress annealing, and magnetic field annealing for the alloy discussed, and future tendency of Fe-based amorphous nanocrystalline prospected in the paper. © (2014) Trans Tech Publications, Switzerland. Source

Lu W.,Advanced Technology and Materials Co.
Cailiao Kexue yu Gongyi/Material Science and Technology

To improve magnetic performances of Finemet alloy, annealing in Ar, transversal and longitudinal magnetic stress annealing were used for the alloy to study the effect of annealing on magnetic properties, microscopic structure and morphology. Magnetic performances were tested by the methods of LCR digital bridge, three of the voltage, and impact, microstructure was measured by XRD, amorphous-nanocrystalline morphology of Finemet alloy was investigated by FESEM. The results show that after annealing in Ar at 540°C, μi reaches the highest and Hc is minimum, and bcc α-Fe(Si) nano-particles emerge on the amorphous matrix, but after annealing in Ar at 580°C, the number and size of nano-particles are both increased and magnetic properties are decreased. Narrow and flat hysteresis, low values of Br/Bs and Pc are achieved by transversal magnetic annealing at 540°C, rectangular hysteresis, high values of Br/Bs and Pc are obtained by longitudinal magnetic annealing at 540°C, and transversal and longitudinal magnetic annealing at 540°C can reduce the values of μi and Hc. So appropriate annealing processes can optimize the magnetic performances of Finemet alloy to meet different applications. Source

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