Sliding wear resistance of biomorphic SiC ceramics

Abstract

Biomorphic SiC ceramics were fabricated from four different wood precursors and their Knoop hardness and sliding wear resistance when sliding against a Si3N4 ball in air were studied.Tribological experiments were performed using a pin on disk apparatus, under normal loads of 2 and 5 N, at a sliding speed of 100 mm/s. The effects of specimen porosity and microstructure on measured wear were evaluated. A commercial sintered silicon carbide ceramic was also tested for comparison. Small differences in friction coefficient comparable to monolithic SiC ceramics were obtained. Several concurrent wear mechanisms are taking place: microfracture, plastic deformation in the Si phase and oxidation of the Si and/or SiC phase. The presence of an oxide tribolayer was assessed using fluorescence microscopy. Wear rates were found to scale with SiC content and depend on residual porosity in the composite.

Conversion of biomorphic silicon carbide from wood powders carbon template

“…Very low hardness value of SiC with 2 hours holding time was attributed by insufficient and incomplete transformation of SiC during infiltration stage. As holding times were prolonged, hardness properties were increased with increasing of SiC content [15]. Dark Red Meranti shows higher hardness compared to Kapur.…”

Learning from Nature: Using bioinspired approaches and natural materials to make porous bioceramics

“…Fabrication of biomorphic SiC from wood templates was pioneered in the mid‐1990s by Ota et al., who developed a three‐stage process involving drying of the organic template at low temperature (60°C), pyrolysis and infiltration with molten Si at high temperature (above 1500°C). This approach was applied and optimized over time in a number of studies that discussed the production of cellular SiC from many ligneous species, such as Sapelli wood ( Entandrophragma cylindricum ), Sipo wood ( Entandrophragma utile ), mahogany ( Swietenia mahagoni ), sugar pine ( Pinus lambertiana ), black walnut ( Juglans nigra ), and maple ( Acer pseudoplatanus ) . Qian et al .…”

“…This approach was applied and optimized over time in a number of studies that discussed the production of cellular SiC from many ligneous species, such as Sapelli wood (Entandrophragma cylindricum), 75 Sipo wood (Entandrophragma utile), 76 walnut (Juglans nigra), and maple (Acer pseudoplatanus). 77 Qian et al 78 also produced cellular SiC at lower temperatures by infiltrating silica sol into a porous biocarbon template from oak wood using a vacuum/pressure infiltration process ( Figure 7A,B). Excellent pictures on wood-derived porous SiC were provided by Greil 79 and De Arellano-Lopez et al 80 Although typical uses of biomorphic SiC are addressed to filtering and phase separation in industrial applications, some studies have been focused on the biomedical field, too.…”

The applicability of WC–10Co–4Cr/Si3N4 tribopair to the different natural waters

“…Si 3 N 4 reacts rapidly with water to produce a film that is easily sheared. The reaction process can be described as follows: Si 3 N 4 + 6H 2 O → 3SiO 2 + 4NH 3 ; SiO 2 + 2H 2 O → Si(OH) 4 [16,17]. Because the SiO 2 and Si(OH) 4 films are easily sheared, the friction coefficient of the tribopair under water is lower than the friction coefficient of the self-mated WC-10Co-4Cr [24].…”

“…Furthermore, some materials with good wear and corrosion resistance, such as Si 3 N 4 and SiC, are not suitable for thermal spraying [15][16][17][18]. Although pure a Si 3 N 4 ceramic has a low toughness, some research indicates that silicon nitride ceramics with whisker additives have increased fracture toughness and wear properties compared to monolithic Si 3 N 4 under both dry and lubricated conditions [19,20].…”