Similar element substitution has been applied for improving glass forming ability （GFA） in AI86NigLa5 amor- phous alloy. The effects of La-Ce and Ni-Co pairs on the GFA, magnetic properties and hardness of Al-Ni-La alloy were investigated by using X-ray diffraction （XRD）, transmission electron microscopy （TEM）, differential scanning calorimetry （DSC）, magnetometer and hardness-tester. The results show the GFA of the samples in the order of Al86（Ni0.5Co0.5）9（La0.5Ce0.5）5〈 A186Ni9Las〈A186Ni9（La0.5Ce0.5）5, implying that similar element substitution has a limited enhancing effect on the GFA of the present Al-Ni-La alloy. In addition, the measured samples display a diamagnetic behavior at room temperature. The variations of diamagnetic behavior as well as the microhardness of the samples are strongly dependent on the microstructure, i.e., the amounts of the icosahedral structure and precipitates, after the similar element substitution in the Al-Ni-La alloy.
Guihua Li Weimin Wang Xiufang Bian Li Wang Jiteng Zhang Rui Li Tao Huang
The effect of compression on the crystallization behavior and corrosion resistance of Al（86）Ni9La5 amorphous ribbons was investigated by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, scanning elec-tron microscopy （SEM） and electrochemistry test. The XRD and TEM results reveal that the compressed Al（86）Ni9La5 ribbons spun with the circumferential speed （R） of 29.3 m/s are in fully amorphous state; however, the compressed ribbons spun with R=14.7 m/s have crystalline phases embedded in the amorphous matrix. The SEM images indicate that after compression, the toughness of the ribbons increases. Electrochemical results show that the compression decreases the stability of the passive film of the Al（86）Ni9La5 amorphous ribbons, because of the compression-introduced free volume, shear bands and crystalline phases; meanwhile, with R=14.7 m/s, the compression-induced crystalline phases in the Al（86）Ni9La5 ribbons increase the corrosion potential.
The crystallization of the （Fe0.78Si0.09B0.13）100-xNix glassy alloys （x=O, 2 and 5） has been investigated by X-ray diffraction （XRD） and differential scanning calorimeter （DSC）. Corrosion resistance analyses have been carried out using electrochemical measurements and corrosion products have been analyzed by scanning electron microscopy （SEM）. The experimental results show that the addition of Ni can promote the nucleation of c^-Fe, retard the decomposition of the metastable borides, and alter the crystallization mode of the present Fe-based glassy alloys. The lattice constant （ao^e） of c^-Fe in the annealed samples shows a decreasing trend with increasing annealing time. The Ni addition can improve the corrosion resistance of the as-quenched Fe-based glassy alloys in H2S04, NaCI and NaOH solutions. The results indicate that Ni can promote the diffusion of Si atoms during quenching and annealing processes.
