Production of Al-based Amorphous Powders and Properties of Their Consolidated Bulk Products

铝基非晶粉末的制备及其块体固结产物的性质近两年来的研究表明，在Al-Y-Ni系中，颗粒尺寸在0.025 mm以下的非晶粉末是用本研究人员开发的高压氦气雾化技术以80%~90%的高成品率获得的。随后，探索了从无定形粉末中制备无定形块体的最佳固结工艺。为探索开发新型轻质高强材料的可能性，对非晶态合金粉末进行了一年的温挤压法制备非晶态块体，并对挤压后材料的组织、密度和性能进行了研究。发现非晶态合金在晶化温度t…以下表现出玻璃化转变现象。在8~12at%Y和5~10%Ni的组成范围内，温度(T_X)较高，并伴随着粘度的显著下降。在此基础上，在T_g附近进行了温固结试验，结果表明，在553~573K范围内，块体材料是以单一的非晶相为主，在583~603K范围内非晶相和晶相共存的结构状态下产生的，但原非晶块体的密度约为98%，需要改进挤压条件才能获得更致密的块体材料。另一方面，这种共存结构的块体材料具有99%以上的高密度，其杨氏模量、抗压强度、弯曲强度和拉伸强度分别为138 GPA、1480 Mpa、1360 Mpa和940 Mpa。值得注意的是，这些强度比SuperJuralmin高2到3倍，SuperJuralmin在晶态铝基合金中具有最高的强度。因此，人们对利用铝基非晶合金开发轻质高强度合金寄予了很高的期望。较少

Production of Al-based Amorphous Powders and Properties of Their Consolidated Bulk Products In the research for the last two years, it has been clarified that amorphous powders in an Al-Y-Ni system with a particle size-below about 0.025 mm are produced in a high yield fraction of 80 to 90 % by using a high-pressure helium gas atomization technique which was developed by the present researchers. Subsequently, an optimum consolidation process to produce an amorphous bulk from the amorphous powders has been searched. For the last one year corresponding to the final year research program, a warm extrusion to produce an amorphous bulk has been tried for the amorphous alloy powders and the structure, density and properties of the extruded materials have been examined, in order to investigate the possibility of developing a new type of high strength material with light weight. The amorphous alloys were found to exhibit a glass transition phenomenon at temperatures just below crystallization t … More emperature (T_x) in a composition range of 8 to 12 at% Y and 5 to 10 %Ni, accompanied by a significant decrease in viscosity. On the basis of this information, the warm consolidation was tried at temperatures near T_g. As a result, it has been clarified that bulk materials are produced in structural states of a mostly single amorphous phase in the range of 553 to 573 K and coexisting amorphous and crystalline phases in the range of 583 to 603 K. However, the density of the former amorphous bulk is about 98 % and an improvement of extrusion condition is required to produce a more dense bulk material. On the other hand, the latter bulk material with the coexistent structure has a high density above 99 % and the Young's modulus, compressive strength, bending strength and tensile strength are 138 GPa, 1480 MPa, 1360 MPa and 940 MPa, respectively. It is notable that these strengths are 2 to 3 times higher than those of Superjuralmin which has the highest strengths in crystalline Al-based alloys. Accordingly, it is highly expected that a high- strength alloy with light weight is developed by utilizing the Al-based amorphous alloys. Less