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

Al基非晶粉末的制备及其固结块状产品的性能在过去两年的研究中，已经阐明，通过使用本研究人员开发的高压氦气雾化技术，以80 - 90%的高产率制备了粒径小于约0.025 mm的Al-Y-Ni系非晶粉末。随后，一个最佳的固结过程中产生的非晶块从非晶粉末已被搜索。在本研究计划的最后一年，我们尝试了用非晶合金粉末进行温挤压，制备非晶块体，并对挤压材料的结构、密度和性能进行了测试，以探讨开发一种新型轻质高强材料的可能性。发现非晶态合金在低于结晶温度的温度下表现出玻璃化转变现象。 关于我们 当Y含量为8 ~ 12原子%，Ni含量为5 ~ 10原子%时，随着温度的升高，粘度显著降低。在此基础上，在T_g附近进行了温固结试验。结果，已经阐明，在553至573 K的范围内以主要单一非晶相和在583至603 K的范围内共存的非晶相和结晶相的结构状态生产块体材料。然而，前一种无定形块体的密度约为98%，需要改进挤出条件以生产更致密的块体材料。另一方面，具有共存结构的后者块体材料具有99%以上的高密度，杨氏模量、压缩强度、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至3倍，Superjuralmin在结晶Al基合金中具有最高强度。因此，高度期望通过利用Al基非晶合金开发具有轻质的高强度合金。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