Development of Aluminum-based Alloys with High Elevated-temperature Strength and Impact Strength by Dispersion of Nanoscale Quasicrystalline Particles

近年来，由于能源和环境问题的重要性增加，高强度铝基轻质合金引起了人们的极大兴趣。众所周知，普通铝合金是通过固溶、析出、细化晶粒度、弥散强化、加工硬化和纤维增强等强化机制发展起来的。然而，这些合金的最大抗拉强度仅为600兆帕左右。为了制备出在高温下仍具有较高抗拉强度的新型铝基合金，应采用硬度高、热稳定性好的非晶态或准晶态颗粒作为析出相。到目前为止，我们已经开展了高强度铝基合金的开发，即纳米级非晶和准晶颗粒弥散分布，应使用非晶或准晶颗粒作为析出物。在本工作中，我们对…的组织和机械特性进行了研究进一步研究了纳米准晶颗粒弥散分布于面心立方铝相的铝基合金。结果表明：(1)熔体淬火Al-Ln-Tm(Ln：稀土元素，Tm：过渡金属)和Al-Etm(Etm：Ti，V，Cr，Mn)-LTm(LTm：Fe，Co，Ni，Cu)高铝含量合金的组织随过渡金属基团数的减少按Al+compound→Al+quasicrystalline→Al+amorphous→amorphous顺序变化。弥散准晶颗粒的粉末冶金铝合金的力学性能为540~670 Mpa。粉末冶金Al&lt；93&gt；Fe3Cr2Ti2合金的σ&lt；Uts&gt；=670MPa值最大。该值优于常规超硬铝合金的σ=600 Mpa。(4)铝合金在573K保温100h后的抗拉强度(σ_&lt；Uts&gt；=350Mpa)大于高温强度目标值300 Mpa。(5)铝合金在573K热处理100h后的高温强度保持不变，与S45C钢的耐磨性也保持良好。

Recently, aluminum-based light alloys with high strength have attracted great interest because of the increase in the importance of energy and environmental problems. It is well known that ordinary aluminum-based alloys have been developed by the use of the following strengthening mechanisms ; i.e., solid solution, precipitation, grain size refinement, dispersion, work hardening and fiber reinforcement. However, the maximum tensile strength for those alloys is only about 600 MPa. In order to fabricate a new aluminum-based alloy with much higher tensile strength even at high temperatures, amorphous or quasicrystalline particles with high hardness and thermal stability should be used as precipitating particles. Until now, we have carried out the development of aluminum-based alloys with high strength were nanoscale amorphous and quasicrystalline particles are dispersed, we should use amorphous or quasicrystalline particles as precipitates.In this work, the structure and mechanical proper … More ties are studied for aluminum-based alloys with nanoscale quasicrystalline particles dispersed into fcc-Al phase. The results are summarized as follows.(1) Structure of melt-quenched Al-Ln-TM (Ln : rare earth element, TM : transition metal) and Al-ETM (ETM : Ti, V, Cr, Mn)-LTM (LTM : Fe, Co, Ni, Cu) alloys with high aluminum concentration changes in order of Al+compound→Al+quasicrystalline→Al+amorphous→amorphous according as decrease of group number of transition metals.(2) The quasicrystalline particle size in the powder metallurgy (P/M) aluminum alloys is in the range of 200 to 900nm.(3) Ultamate tensile strength (σ_<UTS>) of P/M aluminum alloys with dispersion quasicrystalline particles ranges from 540 to 670 MPa. The maximum value of σ_<UTS>=670 MPa was obtained for P/M Al_<93>Fe_3Cr_2Ti_2 alloy. This value is more excellent than σUTS=600 MPa of conventional extra super duralumin(4) Ultamate tensile strength (σ_<UTS>=350 MPa) after holding for 100 hours at 573 K is larger than target 300 MPa for high elevated-temperature strength of aluminum alloy(5) The high elevated-temperature strength remains unchanged after annealing for 100 hours at 573 K and the good wear resistance against S45C steel is also maintained for the extrued alloy tested at the sliding velocity of 0.5 to 2 m/s. Less