Sliding Wear of Alumina/Silicon Carbide Nanocomposites

Abstract

The wear resistance of four Al 2 O 3 /SiC nanocomposites that contained SiC particles of varying average size (40, 200, and 800 nm) was studied under dry sliding conditions and compared with the results obtained in unreinforced alumina. The wear rate of the alumina and the nanocomposites of equivalent grain size increased as the contact load increased; however, the nanocomposite wear resistance at high contact loads was better than that of the alumina by a factor of 3-5. The wear resistance of the nanocomposites of submicrometer grain size was fairly independent of the contact load, and their wear resistance at high contact loads was up to two orders of magnitude better than that of the alumina. The mechanisms responsible for these behaviors were discussed in terms of the microscopic wear mechanisms that were observed on the worn surfaces.

Al2O3–SiC composites prepared by warm pressing and sintering of an organosilicon polymer-coated alumina powder

“…The fracture toughness is slightly higher than the toughness of monolithic aluminas (typically 3-4 MPa m 1/2 ) and is comparable to the values usually reported for Al 2 O 3 -SiC micro-nanocomposites. However, our recent results indicate that the resistance of polymer-derived alumina-SiC nanocomposites to abrasive wear has, in accord with previously published data, [23][24][25] markedly improved with respect to monolithic polycrystalline alumina with comparable grains size. A detailed summary of the results is in preparation.…”

Influence of the SiC grain size on the wear behaviour of Al2O3/SiC composites

“…The smaller sizes led to the more wear resistant composites due to a change in the fracture mode from brittle intergranular fracture to plastic deformation. Rodriguez et al 13 carried out reciprocating ball-on-flat wear tests on Al 2 O 3 and different Al 2 O 3 /SiC composites containing either submicron particles (800 nm) or nanoparticles (40 and 200 nm) of SiC. At high contact loads, the nanocomposites increased their wear resistance in two orders of magnitude referred to the base Al 2 O 3 , meanwhile the submicron SiC particles only increased its wear resistance by a factor of ∼5.…”

“…It was observed that the fracture changed from intergranular in the composites containing coarse SiC particles to transgranular in the nanocomposites. 4,5 The tribological properties of Al 2 O 3 composites containing SiC whiskers, platelets or nanoparticles have been also studied, [6][7][8][9][10][11][12][13][14][15] although a comprehensive analysis of data reported in the literature is complicated, due to the wide gamut of test configurations and experimental parameters. As a general rule, the addition of SiC particles improves the wear resistance of the composites compared to that of the monolithic alumina as detailed below.…”

Quantitative optical fluorescence microprobe measurements of stresses around indentations in Al2O3 and Al2O3/SiC nanocomposites: The influence of depth resolution and specimen translucency

“…The residual stresses drive near-surface cracks that can lead to material removal in these processes. A recent example of such an investigation is provided by the work of Wu et al [5], who studied indentations and scratches in Al 2 O 3 and Al 2 O 3 /SiC nanocomposites in order to further the understanding of the improved surface finish and wear resistance of the nanocomposites compared with Al 2 O 3 [6][7][8][9][10][11]. The investigation centred on residual stress measurements by Cr 3+ fluorescence microscopy.…”