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日益重要，高强度铝基轻合金引起了人们的极大兴趣。众所周知，普通铝基合金是利用以下强化机制发展起来的：即固溶体、析出、晶粒细化、分散、加工硬化和纤维增强。然而，这些合金的最大抗拉强度仅为600 MPa左右。为了制备在高温下也具有较高抗拉强度的新型铝基合金，应采用硬度高、热稳定性好的非晶或准晶颗粒作为析出颗粒。到目前为止，我们所进行的高强度铝基合金的开发都是纳米级非晶和准晶颗粒的分散，我们应该使用非晶或准晶颗粒作为析出物。本文研究了纳米准晶颗粒分散在fcc-Al相中的铝基合金的结构和力学性能。结果总结如下：(1)高铝浓度熔淬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）合金的结构随过渡金属族数的减少依次为Al+化合物→Al+准晶→Al+非晶→非晶。(2)粉末冶金（P/M）铝合金的准晶粒度在200 ~ 900nm之间。(3)具有弥散准晶颗粒的P/M铝合金的极限抗拉强度（σ_<UTS>）在540 ~ 670 MPa之间。P/M Al_<93>Fe_3Cr_2Ti_2合金的σ_<UTS>=670 MPa最大。这个值比生产σ= 600 MPa优秀传统的超硬铝(4)Ultamate抗拉强度(σ_ < ut, > = 350 MPa)持有100小时后573 K大于目标300 MPa铝合金的高温强度高(5)较高的高温强度保持不变后退火100小时在573 K和良好的耐磨性S45C钢也维持extrued合金滑动速度的测试0.5到2米/秒。少

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