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

在过去两年的研究中，本研究人员开发了一种高压氦气雾化技术，在Al-Y-Ni体系中，制备了粒径小于0.025 mm的非晶态粉末，产率高达80% ~ 90%。随后，寻找了从非晶粉末中制备非晶体的最佳固结工艺。根据最后一年的研究计划，在过去的一年里，对非晶合金粉末进行了热挤压生产非晶体的试验，并对挤压材料的结构、密度和性能进行了测试，以探索开发一种新型轻质高强材料的可能性。非晶合金在低于结晶温度的温度下表现出玻璃化转变现象，在% Y和5% ~ 10% Ni的成分范围内，温度（T_x）为8 ~ 12，粘度显著降低。在此基础上，在T_g附近进行了热固结试验。结果表明，块状材料在553 ~ 573 K范围内以单一非晶相的结构状态产生，在583 ~ 603 K范围内以非晶相和晶相共存的结构状态产生。然而，前者的非晶块体密度约为98%，需要改善挤压条件才能生产出更致密的块体材料。而共存结构的后一种块体材料具有99%以上的高密度，杨氏模量为138 GPa，抗压强度为1480 MPa，抗弯强度为1360 MPa，抗拉强度为940 MPa。值得注意的是，这些强度比在结晶铝基合金中强度最高的Superjuralmin的强度高2 ~ 3倍。因此，利用铝基非晶合金开发高强度、轻量化的合金是人们寄予厚望的。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