Effect of calcination temperature on wear resistance of nanosized alumina alpha for biomedicals applications

Friction and wear problems in the prosthesis for substitution of hip joints have been widely studied [1–6]. The choice of the materials for the total hip prosthesis takes a many properties in consideration such as mechanical resistance, tribological proprieties [2-4]. Ceramics can be given a very high, scratch-resistant, low friction coefficient and hight wear resistance. [3-8]. Many studies were investigated friction and wear resistance of hip prostheses [16-21]. Nanocrystalline ceramics are extensively being studied with the aim of improving their mechanical properties by reducing grain sizes [9] crack propagation resistance [3-10]. The structural evolution and tribological behavior of the nanostructured alumina Alpha (α-Al 2 O 3 ) powder, formed by calcinations of gibbsite (Al 2 (OH) 6 ) at different temperatures (100-1200 °C) were reported using X Ray diffraction, XPS, MEB and Type ball on Disk tribometer. XRD analysis indicates that the transformation sequence involves the formation of κ-Al 2 O 3 as an intermediate phase between χ- and α-Al 2 O 3 . The crystallite size of treated alumina (α-Al 2 O 3 ) is as small as 10 nm after calcinations at 1200°C. The sliding wear rate and wear coefficient of friction were lower in the nanocrystalline samples calcined at 1200 °C at same applied load (3, 6 or 10 N). The enhanced friction and wear resistance is endorsed to the finer microstructure, hardness of the sample calcined at 1200 °C