Authors

Abstract

This work focuses on studying the addition effect of the prepared HA powder as
a filler material before and after the calcination process with different volume
fractions (2.5, 5, 7.5, 10, 12.5, 15) vol% to the unsaturated polyester resin matrix.
Many mechanical and physical tests were used to determine the properties of the
prepared composite material which involved tensile strength, the modulus of
elasticity, the elongation percentage at break, compression strength, compression
modulus, bending strength, impact strength, fracture toughness, hardness and water
absorption percentage. For the prepared HA powder, the Ca/P ratio was increased
after the calcination process from 2.45 to 2.51. X- ray diffraction patterns for the
prepared HA powder before and after the calcination process revealed an increase
in the HA peak intensity after the calcination process. Secondary phases also
appeared after the calcination process like (α- Ca3(PO4)2 ) and (β- Ca2P2O7). For the
prepared composite material with both groups of HA filler particles, the results had
shown that the mechanical properties which included: tensile strength, modulus of
elasticity, compression strength, compression modulus, bending strength, fracture
toughness and hardness have been increased with increasing volume fraction of
HA filler particles and reached their maximum value at (7.5 vol%). Furthermore,
the increasing in volume fraction revealed a decreasing in the evaluated properties.
Both the elongation percentage at the break point and the impact strength
decreased with increasing volume fraction of HA filler particles. The water
absorption percentage as a physical property for the prepared composite material
showed an increase with increasing volume fraction of HA filler particles. The
improvement of unsaturated polyester resin with calcined HA filler particles had
shown greater values for the fore-mentioned properties than the improvement of
unsaturated polyester resin with uncalcined HA filler particles.

Keywords