The mechanical grinding effects on the powders of YBa2Cu3Ox supercondu
ctor are examined. The grain size, the oxygen content of the powders d
ecrease, and the content of the amorphous phase, the crystal strain in
crease, with the increasing of grinding time. Except that for amorphou
s phase, the crystallized phase can be refined by the orthorhombic and
tetragonal phases. The refined results show that the diffraction peak
s broaden after continuous grinding. This broadening can be explained
from the crystal strain and the small grain size due to prolonged grin
ding. The lattice constants of the refined phases vary with the grindi
ng time.