급속응고된 Al81-(x+y)Si19NixCey 합금의 나노조직과 기계적 특성

Abstract

In order to produce good wear resistance powder metallurgy Al-Si alloys with high strength, addition of glass forming elements of Ni and Ce in Al81Si19 alloy was examined using SEM, TEM, tensile strength and wear testing. The solubility of Si in aluminum increased with increasing Ni and Ce contents for rapidly solidified powders. These bulk alloys consist of a mixed structure in which fine Si particles with a particle size below 500 nm and very fine Al3Ni, Al3Ce compounds with a particle size below 200 nm are homogeneously dispersed in aluminum matrix with a grain size below 600 nm. The tensile strength at room temperature for Al81Si19, Al78Si19Ni2Ce0.5, and Al76Si19Ni4Ce1 bulk alloys extruded at 674 K and ratio of 10 : 1 is 281, 521, and 668 MPa respectively. Especially, Al73Si19Ni7Ce1 bulk alloy had a high tensile strength of 730 MPa. These bulk alloys are good wear-resistance better than commercial I/M 390-T6. Specially, attactability for counterpart is very little, about 15 times less than that of the I/M 390-T6. The structural refinement by adding glass forming elements such as Ni and Ce to hyper eutectic Al81Si19 alloy is concluded to be effective as a structural modification method.