TITLE:
XRD Evaluation of Relative Mechanical Strength and Irradiation Resistance of Synthetic Diamond
AUTHORS:
E. M. Shishonok, V. G. Luhin
KEYWORDS:
Synthetic Diamond, Crushing Strength, Electron Irradiation, XRD, Crytsalline Distortion
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.3 No.12,
December
17,
2015
ABSTRACT: We continue here our previous work where SD
powders were significantly strengthened by irradiation with electrons of lower
energy under smaller dose. Previous results were obtained from the crushing
strength analysis, no XRD was applied. In present work, powders of synthetic
diamond with low strengthwere sorted on sets with different grain size. As
established, the sets had various crushing strengths and morphology. They were
irradiated with high energy electrons (6.5 MeV, D = 2 × 1019 and D = 6 × 1019 cm?2, Tirr = 450 K) and analyzed using XRD (CuKα) before and after irradiation.
Nonlinear dependences a(Θ) = f{R(Θ), where a(Θ) is lattice constant and R(Θ) is
Raily function, and the discovered extra-splits (additional to α1-α2-doublets
on CuKα) of basic peaks in XRD patterns from the SD sets, testified that
crystal lattice of diamond in sets was variously distorted, like of cBN doped
with rare earth elements. As established, the first irradiation led to decreasing
distortions, the more significantly the higher initial strength of the set. The
second irradiation produced softening and increasing distortions of crystal
lattice of diamond, the more effectively the less initial strength of diamond.
XRD allows indirectly to presort synthetic diamond off the material with
critically low relative mechanical strength as well as evaluate resistance of diamond
crystal lattice against heavy irradiation and other external impacts.