Investigation on corrosion behaviors and mechanical properties of TiB2/7075Al composites with various particle contents

The TiB2/7075Al composites with various particle contents were fabricated through hot-pressing sintering and hot extrusion, and the influence of TiB2 particles on the mechanical properties and corrosion resistance were focused. The results indicated that the grain size was gradually refined and the texture strength was reduced with increasing the TiB2 content due to the greater deformation and recrystallization degrees in the matrix around particles. A high TiB2 content caused a reduction of friction coefficient and an improvement of wear resistance, and the fatigue wear transformed into abrasive wear. Since TiB2 particles hindered the corrosion channels and crack propagation of the composite, the resistances on intergranular and exfoliation corrosion were enhanced by the particles. However, the pitting corrosion was aggravated because the integrity of oxide film on the composite surface was destroyed by the particles. Although the composite exhibits lower electrochemical corrosion resistance than 7075Al without particle, while it could be improved again with increasing the TiB2 content.