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The microstructure evolutions of cascade annealing in α-Zr crystals at T=300K, 400 K, and 500 K for energy of 2, 6 and 10 keV with initially driving directions ⟨0001⟩ and ⟨011¯0⟩ of the pri...

A cast Mg–3Gd–0.6Zr alloy with microscale {101¯2} growth twins was designed successfully. After the alloy was annealed at 350°C for 1 h, the volume fraction of the growth twins was increased by approximately 120%. Gd solute atoms segregated on both sides of twin boundaries and facilitated their formation in the as–cast alloy. The formation mechanism of {101¯2} growth twins in the as–cast alloy was discussed in five aspects: the supersaturation of Gd solute atoms, the segregation ability of Gd, the composition of Gd, the nucleate sites of growth twins, and the total energy of the system. The growth twins elicited remarkable toughening effect but a moderate strengthening effect on the alloy.

In this work, a facile in situ method to prepare the Mg-Al layered double hydroxide (LDH) films on an anodised AZ31 substrate was proposed. The morphology, structure and composition of the LDH films produced within a range of pH values were studied by scanning electronic microscopy, X-ray diffractometer, energy-dispersive spectrum and Fourier transform infrared. The corrosion behaviours of the LDH films were further investigated using electrochemical impedance spectroscopy and potentiodynamic polarisation. The influence of pH on the LDH films was also studied. The results revealed that the pH of solution is important in the formation of the LDH. The films, which formed within the pH range from 10.72 to 11.72, possessed higher crystallinity and denser layered structure. These LDH films could effectively seal the anodic oxide films and enhance the corrosion resistance of the AZ31 substrate.

In this paper, the effect of aluminium on microstructure and mechanical properties of as-cast magnesium–manganese alloy has been investigated by means of X-ray diffraction, optical microscopy and scanning electron microscopy. The results reveal that various Al–Mn intermetallic compounds form with an increase of Al content. As a result, microstructure of AM11 alloy has been effectively refined due to the formation of Al8Mn5 phase along the grain boundary, while Al addition is explained as the main reason on refining the microstructure of AM91 alloy due to its higher grain growth restriction factor value of ∼4.32. The tensile yield strength (TYS) has been improved steadily from 27.4 to 122.9 MPa with increasing Al content, because of the combined effects of grain boundary strengthening, solid solution strengthening and precipitation hardening behaviours.

In the present investigation, the influence of minor Ti addition on the microstructure and mechanical properties of as cast AZ91 magnesium alloy was investigated. The results indicated that the microstructure of the AZ91 alloy with 0·4 wt-% Ti was mainly composed of α-Mg matrix and β-Mg17Al12 eutectic phases. After the addition of 0·4 wt-% Ti to the AZ91 alloy, the average grain size was obviously decreased and the microstructure was drastically refined. The morphology of the β-Mg17Al12 phases was mainly changed from the original partially divorced eutectics to the fully divorced eutectics. A significant enhancement of the tensile properties was found because of titanium addition.

In the present work, thermal and electrical conductivity measurement was conducted on the cast Mg–Zn–Al alloys (ZA alloys) in the wide composition range (1–6 wt-%Zn, 1–10 wt-%Al). For alloys with t...

The harmful effect of silicon in high purity aluminium foils for capacitors could be decreased by additional heat treatment and additional deformation as well as two stage final annealing. It was found that the cube texture fraction in the high purity aluminium foils with higher silicon impurity was increased obviously by additional annealing and rolling. The cube texture of >95 vol.-% could be achieved when the additional rolling deformation of 20–40% was carried out. It was found that the annealing temperature of 200–250°C, not only for additional annealing but also for two stage final annealing, was reasonable for obtaining higher cube texture fraction. The experimental results also showed that the change of hot band annealing temperature had little influence on the cube texture fraction in high purity aluminium foils when additional annealing was carried out at ∼220°C.