Amorphous forming ability of Co-X(X=Cr,Mo,W) magnetic thin films

Co-X （X=Cr, Mo, W） magnetic thin films were prepared by using DC magnetron sputtering, and their structures were examined by using X-ray diffraction （XRD）. The amorphous forming ability （AFA） of the three alloy systems was discussed based on thermodynamic calculation and experiments. The results show that the Co-Mo thin films exhibit the largest AFA among them, and the Co-W thin films are conditiondependent amorphous while the Co-Cr thin films are hard to be amorphous, which is consistent with the thermodynamic calculation. The difference in AFA for the alloys of these three systems is finally ascribed to three main factors： differences in electronegativity, electron density and atomic size between Co and X elements.

Design of FeSiBPCu soft magnetic alloys with good amorphous forming ability and ultra-wide crystallization window

The Fe_(81.3)Si_(4)B_(13–x)PxCu_(1.7) soft magnetic alloys with high Cu and proper P elements addition were synthesized with the aim of ensuring the amorphous forming ability(AFA)while expanding the crystallization window(CW).It is found that the atomic ratio of P/Cu of∼3 is advantageous for AFA whereas a small amount of P addition promotes the precipitation ofα-Fe grains and excessive P addition induces surface crystallization behavior of the present alloys.High Cu concentration can expand the annealing temperature(Ta)window whereas proper P addition effectively expands the annealing time(ta)window.The Fe_(81.3)Si_(4)B_(13-x)PxCu_(1.7) soft magnetic alloy was successfully synthesized with a large Ta window of up to 130°C and ta window of 90 min,which is a breakthrough for nanocrystalline alloys with high saturation magnetization.Microstructure analysis reveals that the ultra-wide CW is related to the unique nucleation mechanism,that is,theα-Fe grains are precipitated attaching to the Cu or CuP clusters and enveloping the Cu clusters,resulting in the high number density ofα-Fe nanocrystals.The ultra-wide CW promises the potential material in flexibly choosing the annealing process according to the performance.

Fabrication of Ti-based Amorphous Composite and Biocompatibility Research

Ti-based alloy Ti64Zr5Fe6Si17Mo6Nb2 （At %） and Ti70Zr6Fe7Si17 （At %） ribbons with a width of 3-5 mm and thickness of about 80 um were fabricated by a single roller spun-melt technique. The feature of the alloy composition satisfies the three empirical rules. Amorphous structures of both alloys were confirmed by the X-ray diffraction pattern. To test the biocompatibility, both alloys were cultivated in the simulate body fluid （SBF）. After 15 days, the Ca phosphates depositions on alloys surfaces were gained. Moreover, n（Ca）/n（P） atom ratio of the deposition is about 1.6/1, which approaches to that of human bone—1.66/1, suggesting that both alloys were with a favorable biocompatibility.

Effect of Rare Earth and Transition Metal Elements on the Glass Forming Ability of Mechanical Alloyed Al–TM–RE Based Amorphous Alloys

The present work aims to compare the amorphous phase forming ability of ternary and quaternary Al based alloys （Al86Ni8Y6, Al86GNi6Y6Co2, Al86NigLa6 and Al86Ni8Y45La15） synthesized via mechanical alloying by varying the composition, i.e. fully or partially replacing rare earth （RE） and transition metal （TM） elements based on similar atomic radii and coordination number. X-ray diffraction and high resolution transmission electron microscopy study revealed that the amorphization process occurred through formation of various intermetallic phases and nanocrystalline FCC Al. Fully amorphous phase was obtained for the alloys not containing lanthanum, whereas the other alloys containing La showed partial amorphization with reappearance of intermetallic phases attributed to mechanical crystallization. Differential scanning calorimetry study confirmed better thermal stability with wider transformation temperature for the alloys without La.