The history of aluminium-lithium alloys development has been reviewed in this paper. According to the strength, weld ability and corrosion resistance, thermal stability and plasticity, aluminium-lithium alloy has been categorized and the defects of aluminium-lithium alloys in early stage have been analyzed. As compared the third generation of aluminium-lithium alloy with normal aluminum alloy and composite materials, it indicates aluminium-lithium alloy has better performance, lower cost and reduced weight. After analyzing the advantages and disadvantages of the rapid solidification, ingot casting metallurgy and electromagnetic simulated microgravity methods in synthesis of aluminium-lithium alloy, it has been found microgravity method has prominent effect on reducing the alloy segregation and lithium losses. Finally, the future development of aluminium-lithium alloys has been discussed.

Grain refinement can greatly enhance the material mechanics, magnetism and other physical properties. Exploration of grain refinement methodology has been one of the hottest fields of material research. Among all the methods, deep supercooling technology is an effective way to refine the grains. In this paper, the grain refinement mechanism has been explored by deep supercooling and rapid solidification technique with introducing grain refined process of pure metal, binary uniform crystalline alloy and the binary eutectic alloy. Furthermore, peritectic grain refinement mechanism and rapid solidification technique have been discussed.

The effects of NiO-doping on the microstructure and piezoelectric properties of PMSZT ceramics were investigated. The experimental results indicate that pure perovskite structure was obtained in the doping range. With the increasing of doping amounts, phases shift from tetragonal phase to rhombohedral phase. The mechanical quality factor (Qm) , Dielectric constant (εr) , electromechanical coupling factor (Kp) and piezoelectric constant (d33) increase with the increasing of doping amounts and then decrease, whereas, dielectric loss (tanδ) decrease and then increase. The ceramics with doping amount of 0.1wt.% sintered at 980 °C have the optim properties of Qm=1345, εr=1853, Kp=0.62, d33=375 and tanδ=0.21%。

Ti-6Al-4V alloy ribbons were successfully prepared by rapid solidification at different roller speeds. The morphology and microstructure of Ti-6Al-4V alloy ribbons were studied by X-ray diffractometer, scanning electron microscope and energy spectrum analysis. The effect of SiO2 on the microstructure and properties of Ti-6Al-4V alloy ribbons were discussed. It is found that the Ti-6Al-4V alloy ribbons consist of β phase with alternated distribution of α' phase and α'' phase. And quicker roller speed promotes the formation of α' phase for the higher rapid solidificationg cooling rate. According to the analysis of energy spectrum data, it is found that there is chemical reactions between the Ti-6Al-4V material and the quartz tube wall during electromagnetic induction melting at high temperature, and the Si elements are segregated at the embossment induced by quick solidification and the phase interfaces between α′ phase and β phase.

No abstract