Mechanical Properties of Nano Particle Dispersed Aluminum Alloys and Elucidation of Their Strengthening Mechanism

本课题的目的是研究用单辊淬火和粉末冶金法制备的快速凝固Al-Fe-Cr-Ti-M(M：Co和Ni)合金的力学性能，并阐明其强化机理。用单辊法制备的(Al_&lt；0.93&gt；Fe_&lt；0.03&gt；Cr_&lt；0.02&gt；Ti_&lt；0.02&gt；)_&lt；100-x&gt；(M：Co或Ni，x=0~3)合金为非晶态单相。2)快速凝固在VC=10 m/S条件下制备的M_x(M：Co或Ni，x=0~3)合金具有50 nm左右的准晶颗粒均匀弥散分布在面心立方Al相中的结构。3)在Al-Fe-Cr-Ti合金中加入稳定过冷液态的Co金属，控制Fe金属和Cr金属的最佳成分，使准晶颗粒弥散分布在Al-Fe-Cr-Ti合金中，可以细化准晶颗粒。Fe5Cr2Ti1Co1合金在573K和673K的高温强度分别为365和208 Mpa。5)准晶颗粒弥散的Al&lt；91&GT；Fe5Cr2Ti1Co1合金具有良好的热稳定性，即即使在573K保温200小时，其组织和力学性能也没有改变。6)准晶颗粒弥散的Al-Fe-Cr-Ti-Co合金在573K下具有压缩塑性加工能力。7)纳米颗粒弥散的Al基合金的强度可以根据Orowan-Martin的析出硬化机制来理解。

The purpose of this project are to study of mechanical properties of the rapidly solidified Al-Fe-Cr-Ti-M (M : Co and Ni) alloys prepared by a single roller quenching method and then by powder metallurgy method, which added a small amount of Co or Ni in order to fine particles in quasicrystalline particle dispersed Al-Fe-Cr-Ti alloys reported previously by us, and to elucidate their strengthening mechanism.Parts of the results obtained up to now are described below :1)Structure of rapidly solidified (Al_<0.93>Fe_<0.03>Cr_<0.02>Ti_<0.02>)_<100-x>M_x (M:Co or Ni,x=0 to 3) alloys prepared by a single roller method at a circumferential speed of copper roller (Vc) of 40 m/s show an amorphous single phase.2)Rapidly solidified (Al_<0.93>Fe_<0.03>Cr_<0.02>Ti_<0.02>)_<100-x>M_x (M:Co or Ni,x=0 to 3) alloys prepared at Vc=10 m/s have the structure in which quasicrystalline particles of about 50 nm dispersed homogeneously in fcc-Al phase.3)Quasicrystalline particles in quasicrystalline particles dispersed Al-Fe-Cr-Ti alloys can be fined down by an addition of Co metal stabilizing the supercooled liquid state and by controlling optimum composition of Fe metal and Cr metal with forming ability of quasicrystalline particles.4)Powder metallurgy quasicrystalline particle dispersed Al_<91>Fe_5Cr_2Ti_1Co_1 alloys show high elevated temperature strength of 365 MPa at 573 K and 208 MPa at 673 K, respectively.5)Quasicrystalline particle dispersed Al_<91>Fe_5Cr_2Ti_1Co_1 alloys shows good thermal stability, that is, its structure and mechanical properties do not change even after holding 200 hr at 573 K.6)Quasicrystalline particle dispersed Al-Fe-Cr-Ti-Co alloys are capable of compression plastic working at 573 K.7)Strength of nano particle dispersed Al based alloys can be understood based on precipitation hardening mechanism by Orowan-Martin.