Ultra‐Low‐Temperature Sintering of Nanostructured β‐SiC

Abstract

A nanostructured SiC was successfully obtained through the decomposition of Al4SiC4 additive during spark plasma sintering at the lowest temperature so far published under the pressing condition of below 121 MPa. The specimen had a relative density of 95% after sintering at 1450°C, and nearly full densification with a grain size of around 70 nm was achieved at 1500°C. Heavy Al segregation occurred at the grain boundaries, which caused the low‐temperature sintering most presumably by promoting grain‐boundary diffusion.

Electrical resistivity of silicon carbide ceramics sintered with 1 wt% aluminum nitride and rare earth oxide

“…The enhanced densification in the specimens containing 5 wt% nano-sized SiC can be understood in terms of (1) the enhanced driving force of the powder compacts for densification due to the high surface area of nano-sized SiC and (2) the increased packing density of the specimens due to the addition of nano-sized to submicron-sized SiC. 23 The enhanced densification or almost complete densification at lower temperatures was observed when nano-sized SiC [26][27][28][29][30] or mechanically alloyed nano-sized SiC powders 20 were used as the starting material. Therefore, the addition of in situ-synthesized nano-sized SiC is beneficial for the densification of submicron-sized SiC with a small amount (1 wt%) of additives.…”

Fabrication, microstructure, and properties of SiC/Al4SiC4 multiphase ceramics via an in-situ formed liquid phase sintering

“…It should be mentioned that the β-to α-phase transformation of SiC was observed. This might have been caused by the dissolution of Al into the SiC grains, which promotes the β-to-α phase transformation of SiC [34,35]. The Al 4 SiC 4 phase could be formed at the temperatures above 1106 ℃, according to the pseudo binary phase diagram of the Al 4 C 3 -SiC system [19].…”

Synthesis of SiC nanoparticles by central composite design response surface methodology directed mechanical milling

“…1. Introduction: Silicon carbide (SiC) is a potential ceramic material for engineering applications such as gas-turbine components, heat exchangers, cutting tools, membranes and electronic devices owing to unique properties of SiC particles such as high melting point (2730°C), low density ((3.21 g/cm 3 ), high thermal conductivity (∼41 W/m°C), chemical stability, high resistance to corrosion, high hardness (HV∼24.5-28.2 GPa), excellent wear and creep resistance [1,2]. Moreover, high thermal conductivities, high melting point and high compressive strength make them attractive for power electronic devices which have high voltage, current and power density [3].…”