Investigation into physicomechanical properties and structure of the Al–Al2O3 composite material fabricated using mechanical treatment of the PAP-2 aluminum powder and reaction sintering of powder billets

Abstract

Mechanical treatment of the PAP-2 powder for 15–180 min results in its granulation and an increase in bulk weight γ_f = 0.4–1.0 g/cm³ in a state of free pouring and γ_s after shaking. Several components of Al differing by the lattice parameter (a₀ = 0.40474–0.40636 nm) have been registered, which is a consequence of structural distortion due to the shocking effect of hard-alloy grinding bodies. The θ-Al₂O₃ crystalline phase is determined (2%). Physicomechanical properties of the Al–Al₂O₃ cermet obtained by reaction sintering in the filtration combustion mode of pressings fabricated from the PAP-2 granulated powder are as follows: density is 2.3–2.5 g/cm³; bending strength is 170–250 MPa; density under the axial and diametral compression is (4.3–7.0) × 10³ J/m², respectively; and relative deformation before destruction under the axial and diametral compression is 6.6–10.8 and 6.2–7.5%, respectively.