Abstract: α-Al₂O₃ micropowder with the even coating of Y₂O₃ was obtained in such an experiment by
using　α-Al₂O₃ powder as base material and Y(NO₃)₃ solution as coating phase through the liquid phase coating method. The aluminium matrix
composite reinforced by α-Al₂O₃ particles modified by Y₂O₃ was fabricated. The microstructure of the composite is more even. The mechanical properties testing indicates that the strengthening effect of
the modified-Al₂O₃ porticles on the Al alloy is improved obviously and the tensile strength of the composites increases by 27.2%, yield strength increases
by 33.1%, and the elongation increases by 10.3%.

Key words: surface modification, liquid phase particle coating, micropowder, Al₂O₃/Al compos- ite, microstructure and mechanical properties