Biomedical Engineering Reference
In-Depth Information
are produced inside the particles or on their surfaces. As the milling
duration increases, the content fraction of such intermediate
compounds increases, leading to a inal product whose properties
are the function of the milling conditions.
Figure 7.1
XRD spectra of Ti and HA (10 vol%) powders mechanically
alloyed: (a) Ti — 0 h, (b) HA — 0 h, (c) Ti-HA — 44 h MA [23].
Figure 7.2
TEM micrographs and electron diffraction patterns (insets) of
the milled Ti-10 vol% HA sample for 44 h — typical amorphous
fragment [23].
The microstructure of milled titanium and hydroxyapatite
powder was also studied by TEM. The sample milled for 44 h was
mostly amorphous (broad rings in the SEAD pattern) as appears
from high-resolution image (Fig. 7.2). Apart from prevailing
amorphous phase, the milled powders contained a small amount
of ine-crystalline and crystalline phases. Lack of any sharp
relections in the XRD pattern (Fig. 7.1c) suggests that the amount
