Investigation on Addition of Kaolinite on Sintering Behavior and Mechanical Properties of B4C

Abstract

The objective of the present investigation was to study the effect of kaolinite addition on sintering behavior and mechanical properties of pressureless sintered B 4 C ceramic. Different amounts of kaolinite, mainly 5 to 30 wt.%, were added to the base material. The in situ reaction of kaolinite with B 4 C generates SiC and Al 2 O 3 , which aid the sintering process and permit pressureless sintering at temperatures between 2050 and 2150°C. Addition of 30 wt.% kaolinite and sintering at 2150°C resulted in improving the density of the samples to about 98.5% of the theoretical density. The composite samples exhibited very good mechanical properties (hardness, flexural strength, and fracture toughness). As wt.% Kaolinite increases, strength and toughness increase, and hardness first increases and then decreases.

Effects of Added Kaolinite on Sintering of Freeze‐Cast Kaolinite–Silica Nanocomposite I. Microstructure and Phase Transformation

“…Above 980°C, metakaolin transforms into a defective crystalline spinel phase (Si 3 Al 4 O 12 ), which subsequently transforms into mullite at higher elevated temperatures . Kaolinite has been used to modify the sintering behavior and to improve the mechanical properties of many systems, such as boron carbide (B 4 C), and mullite . However, to the best of our knowledge, the effect of kaolinite on the sintering of silica nanoparticle has not been studied.…”

Recent progress in B4C–SiC composite ceramics: processing, microstructure, and mechanical properties

“…B 4 C–SiC binary ceramics exhibit better sinterability and mechanical properties than pure B 4 C and SiC ceramics. Recently, the performance of ternary or quaternary systems based on B 4 C–SiC binary ceramics has attracted much attention, such as B 4 C–SiC–TiB 2 , 193–205 B 4 C–SiC–CrB 2 , 206 B 4 C–SiC–NbB 2 , 207 B 4 C–SiC–MoB 2 , 208 B 4 C–SiC–HfB 2 , 209,210 B 4 C–SiC–ZrB 2 , 211,212 B 4 C–SiC–WC, 213 B 4 C–SiC–Al 2 O 3 , 214 B 4 C–SiC–rGO, 215 B 4 C–SiC–carbon nanotubes, 216 B 4 C–SiC–carbon fiber, 217 B 4 C–SiC–Si, 218,219 B 4 C–SiC–Mo, 220 B 4 C–SiC–Al, 221–223 B 4 C–SiC–Al 2 O 3 –MgB 2 , 224 and B 4 C–SiC–Si–TiB 2 . 225 The demand for B 4 C–SiC with good performance promotes further exploration of new materials of ternary or quaternary systems with improved properties based on B 4 C–SiC binary ceramics.…”

Effects of added kaolinite on the strength and porosity of freeze-cast kaolinite–silica nanocomposites

“…Along with other oxides (such as alumina [5][6][7][8], silica [9], and nickel oxide [10]) and in novel sintering processes (microwave sintering [11] and tape-cast-sintering [12]), kaolinite is sintered to fabricate ceramics such as mullite and nickel aluminate spinel. Recently, the reinforcement effects of kaolinite in matrix materials, such as boron carbide [13], have also been investigated.…”