Development on research of advanced rare-earth aluminum alloy

The active mechanisms of rare earth element erbium ( Er ) in part of aluminum alloys were investigated. Based on the investigation of the effect of the unitary rare earth elements (Er, La, Y, Ce, Nd, Gd, and Sc) and the transition element zirconium on the aluminum alloys, it is concluded that, with Er alloyed, high purity aluminum and Al Mg alloys are featured with refined grain structure, superior heat stability and even higher hardness or tensile strength with unchanged ductility; but Er is not beneficial to the mechanical property of Al Cu alloy, so is Sc. It may also be concluded, to most of the aluminum alloys, Er can be an effective alloying element, like Sc; and for the lower price of Er, the cost of modifying aluminum alloys by Er will be reduced.

Preparation and Mechanical Properties of Misch Metal Based Bulk Metallic Glasses

The formation, thermal stability and mechanical properties of Misch metal （Mm）-based alloy bulk metallic glasses （BMGs） with composition of Mm55Al25Cu10Ni5Co5 were investigated by means of X-ray diffraction, differential scanning calorimetry, differential thermal analysis and compression test. The results indicate that the Mm-based BMGs exhibit a distinct glass transition and a wide supercooled liquid region Δ Tx（ 〉 60 K） before crystallization. The alloy can be fabricated into bulk glassy form of 3 mm in diameter by copper mold casting methods. Compared with the La55Al25Cu10 Ni5Co5 BMG, the Mm55Al25Cu10Ni5Co5 BMG shows higher compression fracture strength and lower cost. A new parameter γ and melting temperature Tl are closely correlated with the glass forming ability （GFA） of Mm-based alloys.

Influences of Misch Metal on Microstructure and Mechanical Properties of Mg-10Li-4Al Alloy

Mg-10Li-4Al and Mg-10Li-4Al-0.6RE alloys were prepared with vacuum induction melting method. The influence of RE on microstructure and mechanical properties was studied with SEM, XRD and tensile tester. The results showed that, the addition of RE made the α(Mg) phase disappeared and caused the formation of Al3La phase. And it improved both the tensile strength and elongation percentage of alloys.

Crystallization Kinetics of Misch Metal Based Bulk Metallic Glasses

The crystallization kinetics of Mm55Al25Cu10Ni5Co5 bulk metallic glass （BMG） was investigated by means of differential scanning calorimetry （DSC） in the mode of continuous heating or isothermal annealing. It was found that the apparent activation energy Eg, Ex and Ep of the BMG calculated by Kissinger＇s method were 189.58, 170.68 and 170.41 kJ·mol^-1, respectively, which was bigger than those of La55Al25Cu10Ni5Co5 BMG indicating that thermal stability of the former was higher than that of the latter. The local activation energy obtained using Ozawa equation decreased as crystallization proceeded except for the initial stage. The Avrami exponents were calculated to be in the range of 3.26 - 5.23 for different crystallization stages and isothermal temperatures. This implied that crystallization of Mm55Al25Cu10Ni5Co2 BMG was governed by diffusion-controlled three-dimensional growth with either reduced or increased nucleation rate, depending on isothermal temperature. Inconsistency of thermal stability with glass-forming ability for Mm（La）-Al-Cu-Ni-Co BMGs was discussed.

稀土对ZnAl27合金组织性能影响的研究

本文对ZnAl 27合金及加入稀土后合金的室温及高温机械性能、超塑拉伸性能及抗蚀性能进行了系列实验,微量稀土加入能使合金的所有性能得到改善。文中还初步分析了加入稀土RE后的不同状态的金相显微组织,并探讨了RE对合金的作用机理。

富镧混合稀土镍铝系合金贮氢特性的研究

本文研究了以富镧混合稀土(简称Ml)为吸氢元素组成的MlNi_(5-x)M_x(M为Al等合金元素)合金的贮氢特性。测定了试验合金在不同温度下的等温线和动力学曲线及吸、放氢前后的品格常数的变化,计算出该合金氢化物的热焓和熵变,并就主要贮氢特性与MlNi_5和LaNi_5比较,说明本合金只有一系列的优点,特別是抗中毒和再生性能优良,是一种很有价值的贮氢合金。