Advanced Materials Research Vols. 535-537

Abstract: 6063 aluminum alloys are used as the luggage rack’s material on high-speed trains recently. The study on the AZ31B magnesium alloy is aimed to demonstrate the feasibility of the magnesium alloy’s application as the material of the luggage rack on high-speed trains. First, the mechanical properties of the AZ31B magnesium was obtained after a series of experimental tests on basic mechanical properties of the AZ31B magnesium alloy. The results show that the strength of the magnesium alloy is 1.25 times of the 6063 aluminum alloy and the impact toughness of the AZ31B magnesium alloy is twice as much as the 6063 aluminum alloy. Second, the stress distribution and the maximum value of the equivalent stress in given loading conditions was obtained by finite element strength analysis on the structure of the aluminum alloy luggage rack on high-speed trains. And the FE analysis results indicate that if the AZ31B magnesium alloy is used as the material of the luggage rack instead of the 6063 aluminum alloy, it will have a weight loss of the luggage rack for approximately 33%. In addition, the application of AZ31B magnesium alloy has more advantages in energy-saving, environmental protection and safety control.

Abstract: Two high boron alloyed stainless steel composite plates(HBASSCP) which have different Cr and Ni contents were prepared by composite casting and hot rolling process. By means of metallographic observation and x-ray diffraction analysis, the matrix microstructure of calding and core is ferrite and the boride phase in core material is identified as brittle Fe2B for HBASSCP which has lower Cr and Ni contents, while the matrix microstructure of calding and core and the boride phase are mainly austenite and (Fe,Cr)2B respectively for HBASSCP which has higher level of Cr and Ni contents. After solution treatment, ferrite had changed into martensite which do not have plasticity for composite plate with lower Cr and Ni contents, but the elongation and the tensile strength of HBASSCP with high contents of Ni and Cr has reached up to 12.45 % and 558MP respectively. The mechanical properties has met ASTM standard specification for borated stainless steel plate for nuclear application.

Abstract: The creep and microstructures of DD6 single crystal superalloy with [001] orientation at 760°C and 785MPa were investigated. The results show that large a/2 dislocations are spread and concentrated in matrix channels during incubation period, and few of stacking faults are observed at later stage of incubation period. The stage of primary creep is characterized by the stacking faults shearing γ' phases, and the density of a/2 dislocations in the matrix continues to increase. The density of the stacking faults increases during the stages of secondary and tertiary creep.

Abstract: In this paper, we used a simple process of anodization fabrication TiO2, TiO2, TiO2-MoO3, and TiO2-Ta2O5 nanotubes. Those high dielectric constant and large surface area of NT materials are suitable used for the ultracapacitors. Based on the nanotube structural characteristics such as pore diameter, porosity, and tube length, we also investigated and calculated the NT specific capacitance.

Abstract: The heat treatment microstructure of Fe-0.36C-1.4B alloy after austenitizing at 1000°C and water quenching then tempering at 200°C were studied by TEM and selected area diffraction. The results indicate that the alloy has typical microstructure of hypoeutectic cast iron because of boron addition. After quenching, the microstructure of the alloy was made up of martensite and B-containing carbide Fe23(C, B)6.

Abstract: In this study, the Al-Zn-Mg-Cu alloy was prepared by spray forming process. The ageing precipitation and strengthening behavior of the spray formed Al-Zn-Mg-Cu alloy were studied by microhardness tests, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) .The results show that the main strengthening precipitates of the spray formed Al-Zn-Mg-Cu alloy are GPI (solute-rich clusters), GPII (vacancy-rich clusters) under peak aging condition. The effect of the microstructure on ageing hardness is controlled by the size and amount of the existing precipitates, and therefore depends critically on the ageing temperature and ageing time. Strength of this alloy is influenced significantly during natural ageing at room temperature, which is related to the dominant formation of GPI. During the initial stage of artificial ageing at 120°C, strong age-strengthening response is due to the formation of GP zones (both GPI and GPII ) .During later stages of artificial ageing , GPII precipitation is accelerated significantly but GPI is not affected clearly.

Abstract: To analysis the microstructure and properties of super-high strength Al-Zn-Mg-Cu alloys containing Zr ,Ni and Mn, the apparatus of SEM、TEM、and Tensile machine was used. The results show that the microstructure was fine and homogeneous, the phases became finer for the alloys with adding Zr, Mn, Ni than the alloy with Zr only after solid solution. The ultimate tensile strength of the alloy was 850MPa and the elongation was 5% respectively at peak aging.

Abstract: Al-Ti-B-RE master alloy was prepared by casting of pure Ti. To improve the quality and reduce the cost of α- Al, the Al-Ti-B-RE master alloy was added to α-Al in molten and diluted state. The refining method had the advantages of shorter contact time and better refining effect. The array of the second phase particles was separated and the nucleating rate was greatly increased. Analysis and comparison of the refining effects were by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy (OM).The refining experiment showed that the molten and diluted state Al-Ti-B-RE by oneself had better grain refining performance and had obvious advantages over Al-Ti-B in domestic.

Abstract: Ni-Ti-Nb wide hysteresis shape memory alloys of three Ni/Ti ratio components were manufactured by vacuum induction melting. The transformation temperature, mechanical properties and recovery strain were studied by using differential scanning calorimeter and material testing machine. It shows that with Ni/Ti ratio increase, the transformation temperature and mechanical properties decrease. Shape recovery strain is higher when Ni/Ti ratio is 1.068, with recovery strain range from 6.8 to 7.5. The faster the cooling rate after annealing, the higher is the transformation temperature, and the lower are the mechanical properties and recovery strain.

Abstract: Mg-8.5Li-1Al-1Ce alloys were prepared with vacuum induction melting method. Uniaxial rolling deformation of alloys was obtained by two-roll milling. The effect of rolling deformation was studied on the microstructure and mechanical properties of Mg-8.5Li-1Al-1Ce. The results show that the microstructure morphologies of α-phase, β-phase and Al2Ce-phase go through different changes under different rolling percentages, and the mechanical properties are improved with increasing deformation. Besides the basal slip system, the prism and pyramidal slip systems are also activated in α(Mg) phase, with all the slip systems in β(Li) phase being uniformly activated.