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

本课题旨在研究快速凝固Al-Fe-Cr-Ti-M合金的力学性能（M：采用单辊淬火法制备了Co、Ni合金，并在Al-Fe-Cr-Ti准晶弥散合金中加入少量Co或Ni，用单辊法制备的（Al_<0.93>Fe_<0.03>Cr_<0.02>Ti_<0.02>）_<100-x>M_x（M：Co或Ni，x=0 ~ 3）合金，在铜辊圆周速度（Vc）为40 m/s时，其组织为单相非晶<0.93><0.03><0.02><0.02><100-x>;（M：Co或Ni，x=0 ~ 3）在Vc=10 m/s下制备的合金具有50 nm左右的准晶颗粒均匀分散在fcc-Al相中的结构; 3）在准晶颗粒分散的Al-Fe-Cr-Ti合金中，通过添加稳定过冷液态的Co金属和控制具有准晶颗粒形成能力的Fe金属和Cr金属的最佳成分，可以细化准晶颗粒。准晶颗粒弥散的Al_<91>Fe_5Cr_2Ti_1Co_1合金在573 K和673 K的高温强度分别达到365 MPa和208 MPa<91>。在573 K下保持200 h后，其结构和机械性能没有变化。6）准晶颗粒分散的Al-Fe-Cr-Ti-Co合金能够在573 K下进行压缩塑性加工。7）纳米颗粒分散的Al基合金的强度可以基于Orowan-Martin的沉淀硬化机制来理解。

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.