Oscillatory pressure-assisted sinter forging for preparation of high-performance SiC whisker reinforced Al_(2)O_(3) composites

In this work,a novel process,oscillatory pressure-assisted sinter forging(OPSF),for the preparation of high-performance ceramic composites was reported.Compared with the samples made by conventional sinter forging(SF)and hot oscillatory pressing(HOP),the SiC whisker reinforced Al_(2)O_(3) composites(SiCw–Al_(2)O_(3))prepared by OPSF at the same temperature exhibited a higher density and significantly improved the mechanical properties.The improvements in densification and performance are attributed to simultaneous enhanced shear deformation at both macro-and micro-scales,resulting from the combination of die-free configuration and oscillatory pressure of OPSF.And the strength of grain boundary is greatly increased when the temperature reaches 1600℃ of OPSF,due to that the grain-boundary sliding became pronounced at higher temperatures.The current results shed light on a powerful technique for preparing ceramic composites,which is likely applicable to other systems.

Two-dimensional vanadium carbide(V2CTx) MXene as supercapacitor electrode in seawater electrolyte

In this study,two-dimensional V2CTx MXene has been prepared by selectively etching Al layers from V2 AlC MAX phase by NaF+HCl etching at 90℃for 72 h and its performance as supercapacitor(SC)electrode were tested using simulating seawater as electrolyte.V2CTx MXene-based electrodes shows a good capacitance of 181.1 F/g,which is in accordance with the volumetric specific capacitance of 317.8 F/cm^3,and with 89.1%capacitance retention even after 5000 cycle.Compared with other MXenes,V2CTx have better electrochemical performance as SC electrode.This work provides an innovative strategy to apply V2CTx MXene as SC electrode in safety and effective seawater electrolyte.

Sintering behavior of alumina whisker reinforced zirconia ceramics in hot oscillatory pressing

Alumina whisker reinforced zirconia ceramic composite was prepared by both hot oscillatory pressing(HOP)and conventional hot pressing(HP).The results show that compared with HP,HOP can significantly increase the final density and densification rate of the material.Analysis of densification kinetics reveals that the predominant densification mechanism transits from grain boundary sliding in the beginning to the diffusion in the later stage.The main effect of the oscillating pressure is to increase the densification rate in the process of grain boundary sliding.The current study suggests that HOP is a promising technique for densifying whisker reinforced ceramics.