Structure and thermal stability of nanoscale Al3(Zr,Yb) dispersoids in Al–Zr–Yb alloy was studied by TEM, OM observation combined with XRD, SAED, EDAX and hardness analysis. The results showed that addition of Zr and Yb forms high-density homogeneous Al3(Zr,Yb) dispersoids with coherent cubic L12 structure, compared to add Zr. Al3(Zr,Yb) dispersoids contains two types, which one is Yb incorporating Al3Zr, the other is Zr incorporating Al3Yb. Zr incorporating Al3Yb dispersoids exhibit unique core/shell structure, which structure leads to have better thermal stability and inhibit-recrystallization ability compared to Al3Zr in pure aluminum.Highlights► Addition of Zr and Yb forms high-density homogeneous Al3(Zr,Yb) dispersoids. ► Al3(Zr,Yb) dispersoids contains two types. ► Zr incorporating Al3Yb dispersoids exhibit unique core/shell structure. ► Al3(Zr,Yb) has good thermal stability and inhibit-recrystallization ability.

Ti-X-N (X=Al, Si or Al+Si) coatings were grown onto cemented carbide substrates by cathodic arc evaporation. The hardness of the coatings was obtained by nanoindentation and the microstructure was investigated by XRD, XPS and SEM. Solid solution hardening results in a hardness increase from 24 GPa for TiN to 31.2 GPa for TiAlN. The higher hardness values of 36.7 GPa for TiSiN and 42.4 GPa for TiAlSiN are obtained by the incorporation of Si into TiN (TiAlN) coatings due to the formation of special three-dimensional net structure consisting of nanocrystalline (nc) TiN (TiAlN) encapsulated in an amorphous (a) Si3N4 matrix phase. Furthermore, the nc-TiAlN/a-Si3N4 coating shows the best machining performance.

The effect of adding magnesium to lithium on lithium electrochemical behavior in 4 mol L−1 LiOH is studied using electrochemical techniques. The results show that the hydrogen evolution rate is decreased with increasing Mg content. Through theoretical analysis and X-ray (XRD) investigation, MgH2 and Mg(OH)2 are created on the surface film of lithium–magnesium alloys after discharge. The porosity of the lithium surface film is decreased by MgH2, Mg(OH)2 combined with LiOH and LiOH·H2O and the hydrogen evolution rate is decreased effectively. Magnesium addition to lithium reduces the extent of hydrogen evolution by alteration of the hydride–hydroxide layer also reduces the extent of anodic dissolution without a significant change in the system efficiency.

The effect of cerium as an inhibitor on the discharge and hydrogen evolution at a lithium anode in alkaline electrolyte with additives was evaluated. The electrochemical behaviors of lithium and lithium–cerium alloy are assessed by hydrogen evolution collection, discharge current density, anodic potential, XRD (X-ray diffraction) and scanning electron microscope (SEM). For these conditions, the results show that minor addition of cerium to lithium decreased the hydrogen evolution on the surface of lithium–cerium alloy in an alkaline electrolyte containing corrosion inhibitors. SEM and XRD observation showed that the slow dissolution of lithium–cerium alloy generates the formation of LiOH, LiOH·H2O and Ce(OH)3. The lithium–cerium surface is less porous than the lithium surface. Hydrogen evolution decrease, prompted by adding cerium to lithium, which is related to reduced porosity of the film enhanced by Ce(OH)3.

The effects of the alkaline earth metal calcium on the electrochemical behavior of lithium anode in 4 mol L−1 LiOH and NaOH solutions were investigated via hydrogen collection, X-ray diffraction (XRD) and scanning electron microscope (SEM). It was found that adding minor calcium to lithium decreased the hydrogen evolution on the surface of lithium–calcium alloy in the alkaline electrolyte containing corrosion inhibitors. The SEM image and XRD analysis showed that calcium formed calcium hydride on the surface of lithium–calcium alloy anode. The hypothesis has been proposed that the hydrogen inhibition effect is caused by calcium hydride combined with LiOH and LiOH·H2O formed on the anode surface. The formation of calcium hydride and LiOH and LiOH·H2O reduced the porosity of the film and water penetration onto the active sites of the lithium–calcium alloy.