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Mg-(4- x)Nd- x Gd-0·3Sr-0·2Zn-0·4Zr (wt.-%, x = 0, 1, 2, and 3) alloys with various Gd/Nd ratios were prepared by gravity casting, solution-treated and then hot extruded. The microstructures, mechanical properties at room temperature, corrosion behaviour in simulated body fluid of the as-extruded alloys were studied. The as-extruded alloys undergo partially dynamic recrystallisation, and the equiaxed grains become coarse with increasing Gd/Nd ratio. The strength of the alloys increases first and then decreases with increasing the Gd/Nd ratio; however, the elongation of the alloys increases apparently with increasing Gd/Nd ratio. Both immersion test and polarisation test indicate that the corrosion rate of the as-extruded alloys is reduced with increasing the Gd/Nd ratio, and the alloys exhibit relatively uniform corrosion morphologies. [ABSTRACT FROM AUTHOR]

Mg-2·2Nd- xSr-0·3Zr alloys (wt-%, x = 0, 0·4, 0·7 and 2·0) were prepared by gravity casting to study the effects of Sr addition on the microstructure and corrosion resistance of Mg-Nd-Zr alloys in simulated body fluid (SBF). Phases were identified by X-ray diffraction, and microstructure was observed with optical microscopy and scanning electron microscopy. Corrosion resistance of the alloys was determined by evaluating mass loss and hydrogen evolution during immersion in SBF. Mg17Sr2 phase was formed, and the grain size decreased with additional Sr addition. For the grain refinement and more continuous second phase, which could improve the corrosion resistance, the alloy with 0·7 wt-%Sr showed the slowest corrosion rate, whereas the alloy with 2·0 wt-% showed the fastest corrosion rate due to the increased volume fraction of Mg17Sr2, which led to severe local microgalvanic corrosion. [ABSTRACT FROM AUTHOR]

TiO2 nanomaterials have many promising applications in environmental and energy areas due to their advantages of physical and chemical stability, high activity, non-toxicity and low price. In the present paper, the hierarchical TiO2 nanomaterials with thickness >10 μm were synthesised using Ti-Cu amorphous alloy as the starting material. The field emission scanning electron microscopy, X-ray diffraction and transmission electron microscopy were used to characterise the morphology and structure of the TiO2 nanomaterials. The hierarchical TiO2 nanomaterials exhibited high specific areas of >100 m2 g−1. The phase composition of TiO2 was controlled by adjusting the concentration of SO42− in the immersing solution. The influence mechanism of SO42− on phase composition of TiO2 nanomaterials was discussed. The mixed phase of anatase and rutile had higher photocatalytic efficiency than single phase in degradation of rhodamine B under visible light. The hierarchical TiO2 nanomaterials had potential applications in photocatalyst and solar cell. [ABSTRACT FROM AUTHOR]

Mg-(4- x)Nd- xGd-0·3Sr-0·2Zn-0·4Zr (wt-%, x = 0, 1, 2 and 3) alloys were prepared by gravity casting. Microstructure was analysed by X-ray diffraction, optical microscopy and scanning electron microscopy respectively. The α-Mg and Mg41Nd5 phases existed in the as cast alloys with 4% and 3% Nd addition, while the new Mg3Gd was found in the alloys with 3% Gd addition. The volume fraction of the second phase reduced with increasing Gd addition and the microstructure was refined by the Gd addition. The corrosion resistance of the alloys was evaluated by mass loss, hydrogen evolution and Tafel polarisation tests. The results showed that the corrosion rate of the alloys decreased with increasing Gd addition even though the corrosion rates of the alloys obtained by different methods showed different values. Moreover, the corrosion morphologies of the alloys were uniform. [ABSTRACT FROM AUTHOR]

Effect of the particle size of TiC and TiN on the microstructure and mechanical properties of Ti(C,N) based cermets has been evaluated. Ti(C,N)–WC–Co cermets made from four groups of mixed raw powders of different sizes were manufactured by vacuum sintering. The microstructure and composition were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDX). The result shows that the four samples have the typical microstructures of 'black core/grey rim'. The mechanical properties of the cermet manufactured from submicron TiC and nano TiN are the best among the four samples. [ABSTRACT FROM AUTHOR]