Si 3 N 4 as a structural ceramic is desirable for applications in spacecraft, transportation, and energy, but its poor high-temperature properties still do not satisfy the actual requirements. Here, a TiC 0.3 N 0.7 reinforced Si 3 N 4 ceramic is successfully designed and fabricated via the high-temperature nitridation of TiC x . It is found that TiC 0.3 N 0.7 grains with the size of 1-2 μm are uniformly dispersed in the Si 3 N 4 matrix and show a firm bond with substrate. Compared with pure Si 3 N 4 , the doping of harder TiCN phase can effectively improve ceramic's hardness and fracture toughness at a certain temperature. Importantly, the ceramic material displays extraordinary wear resistance across a wide temperature range (eg, the wear rate of TiC 0.3 N 0.7 containing Si 3 N 4 over 63 times and 178 times better than pure Si 3 N 4 at 600 and 900°C, respectively). More broadly, a correlation between wear mechanism and temperature is established, and the result shows that the mechanical strength and tribochemical oxidation as two key factors determine the wear behavior of the material. These results developed here can provide a springboard for preparation and optimization of multiphase ceramics that serve under hightemperature conditions. K E Y W O R D S high temperature, mechanical properties, nitridation, Si 3 N 4 , wear/wear resistance
In this work, a design concept of bioinspired functional
surfaces
is proposed for lubricant control at surfaces and interfaces subjected
to external thermal gradients. Inspired by the conical structures
of cactus and the motion configuration of Centipedes, a bioinspired surface of wedged-groove with
an oriented capillary pattern is constructed. The effect of geometrical
parameters on the directional lubricant manipulation capacity and
sliding anisotropy is discussed. It is found that by regulating the
orientation of the capillary pattern, a controllable lubricant self-transport
capacity can be achieved for varying conditions from surfaces to interfaces,
with or without thermal gradients. The lubricant self-transport process
is captured, and the mechanism is revealed. The design philosophy
of the proposed bioinspired functional surface is believed to have
potential applications for lubricant control in modern machinery and
complex liquid control in lab-on-a-chip and microfluidics devices.
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