Characterization of alumina titania carbon nanotube composite prepared by powder metallurgy method

The present work investigates the characterization of alumina titania carbon nanotube (Al2O3–TiO2–CNT) composite prepared by powder metallurgy (PM). The properties of Al2O3-TiO2 composite have high hardness, chemical and thermal resistance, wear and corrosion resistance. This made Al2O3–TiO2 composite used in various applications. However, Al2O3–TiO2 composite have lack due to low fracture toughness and brittle. To overcome the problem, CNT was reinforced into Al2O3–TiO2. CNT are most suitable material as reinforcement due to attractive mechanical properties, low density and high fracture toughness. Elemental powders of Al2O3, TiO2 and CNT were milled in a low energy ball mill using different milling time at 15, 30, 45 and 60 h with 10 mm ball size. Then, the powder was compacted at different pressure at 200, 400, 600 and 800 MPa. The peak XRD of TiO2 and CNT become diminished with increasing milling time. The powder that milled at 60 h has lowest crystallite size and highest internal strain due to finer and homogenous particle size deform during milling. The microstructure of particle size milled powder become smaller and finer with increasing milling time. Apart from that, after compaction, 45 h of milled powder have highest green density and densification parameter with increasing the compaction pressure from 200 to 800 MPa. This due to small particle of TiO2 and CNT become diffuse into void of Al2O3 matrix. Thus,Al2O3–TiO2–CNT composite have low porosity and increase in fracture toughness.