Papers by Keyword: AL-CU-Fe

Abstract: The Al₆₅Cu₂₀Fe₁₅ (in at.%) rapidly solidified ribbon in the form of brittle flakes was produced by melt-spinning technique. It consists the cell or dendrites of the icosahedral quasicrystalline I-phase surrounded by copper rich cubic τ-Al(Cu, Fe). The pulverized ribbon (fraction <32 μm) was subjected to NaBH₄ or 20% aqueous NaOH treatment, which led to the formation of oxide in the form of thin flakes at the outer layer of the powder particles. Test of the catalytic properties of the as spun ribbon and powder before and after treatment was made in the reaction of phenylacetylene hydrogenation. It was shown that for as received ribbon, even at very mild conditions (60 °C, H₂ pressure of 5 bar), 40% of phenylacetylene was converted to hydrogenation products with 0.7 styrene/ethylbenzene ratio. The use of pulverized ribbon resulted in improvement of activity, with the same ratio of reaction products. The effect of treatment with NaBH₄ led to improvement of the catalyst activity, while strongly alkaline solution of NaOH worsened significantly the catalytic activity, but improved selectivity to styrene (styrene/ethylbenzene=1.2).

Abstract: Structural characteristics and thermal behavior of the conventionally solidified Al₈₀Cu₁₄Fe₆, was investigated by X-ray diffraction, optical microscopy, and differential thermal analysis techniques. It was found that the formation of quasi crystalline phase occurs after annealing for relatively low temperature (500°C) during a short time.

Abstract: Al-Cu-Fe with an atomic ratio of 70:20:10 was selected for preparing the quasicrystalline coating by low power plasma spraying. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used for analyzing the phase component and microstructure of the quasicrystalline coating. It was found that the best quality of quasicrystalline coating was obtained under a current of 400A and a voltage of 40V. XRD results show that, using these parameters, a relatively higher content of quasicrystalline phase can be acquired in the coating. SEM results show that the sprayed coating has a low level of porosity.