There has been great progress in the last decade in the synthesis of nanopowders with highly controlled size and size distribution. Meanwhile, the development of an unconventional pressureless two-step sintering strategy enabling densification without grain growth provides a novel technology suitable for commercial production of nanograin ceramics. The particular interest concerning bulk dense nanograin ceramics is the manifestation of ferroelectricity, which remains a fundamental issue to be...

The study of cordierite ceramic is the need of the hour in present technological world for various advanced engineering applications. Cordierite, which has relatively poor mechanical properties, has induced the use of various dopants to study the improvement in mechanical properties. Thirst of seeking new materials with good mechanical properties has revived the research on ceria doped cordierite. Present research conducted on pure cordierite and ceria doped cordierite ceramics has investigat...

SiC fiber reinforced SiBCN ceramic matrix composites (CMCs) have been prepared by mechanical alloying and consolidated by hot pressing. During the sintering process, amorphous SiC fibers crystallized seriously and transformed into β-SiC. Meanwhile, the interfacial carbothermal reactions caused the strong bonding between the matrix and fibers. As a result, SiC_f/SiBCN fractured in a typical catastrophic manner. Room-temperature mechanical properties reached the maximums...

Novel environmentally friendly inorganic red pigments based on calcium bismuth oxide, Ca₃(Bi_1−xRE_x)₈O₁₅ (0 ≤ x ≤ 0.09; RE = Sc³⁺, Er³⁺, Y³⁺, Ho³⁺ and Dy³⁺), were successfully synthesized and the color properties were characterized. The color of these pigments depended on the composition and the synthesis condition, and the most vivid red color...

Barium strontium titanate (Ba_0.8Sr_0.2TiO₃, BST) nanocrystalline ceramics have been synthesized by high energy ball milling. As the sintering temperature increases from 1200 ℃ to 1350 ℃, the average grain size of BST ceramics increases from 86 nm to 123 nm. The X-ray diffraction (XRD) studies show that these ceramics are tetragonal. The phase and grain size of the sintered pellets have been estimated from the XRD patterns, scanning electron micros...

Bismuth layer-structured ferroelectric ceramics of Na_0.5Bi_4.5-x(Nd_0.5Ce_0.5)_xTi₄O₁₅ (NBT-x, 0.0 ≤ x ≤ 0.4) were synthesized by a traditional solid-state reaction. The effect of (Nd,Ce) substitution for A-site on the microstructure and electrical properties of Na_0.5Bi_4.5Ti₄O₁₅ (NBT)-based piezoelectric ceramics was investigated. X-ray...

A flower-like hematite microstructure has been successfully prepared by a facile hydrothermal synthesis method without using any organic solvents or templates. It is revealed that the flower-like hematite microstructure consists of well-crystallized nanorods with the average diameter of about 100±15 nm and average length of about 900±100 nm growing from the centers. A possible growth mechanism of the flower-like α-Fe₂O₃ microstructure is proposed and discus...

Literature has reported the synthesis of barium calcium titanates by various synthesis methods such as solid state reaction, co-precipitation and polymer precursors. These compounds are usually obtained using calcium carbonate (CaCO₃), barium carbonate (BaCO₃) and titanium oxide as starting materials. This study investigated the effect of different starting reagents on the synthesis of Ba_0.8Ca_0.2TiO₃ (BCT) by complex polymerization method...

A Pt/CeO₂–ZrO₂–Bi₂O₃/SBA-16 (Santa Barbara Amorphous No. 16) catalyst was prepared by hydrothermal and wet impregnation methods for catalytic purification of 1,4-dioxane in water. SBA-16 has a number of mesopores and the average size of the pores is 9.4 nm. In the present catalyst, platinum and CeO₂–ZrO₂–Bi₂O₃ were successfully dispersed in the pores of the SBA-16 support, and the temperature dependence of...

Yttria stabilized zirconia (YSZ) film has been screen printed and sintered on a rigid substrate. The constrained sintering caused the formation of multiple microcracks and most critically large “blister” defects. The morphology of such defects has been characterized by scanning electron microscopy (SEM). It was revealed that the film surface exhibits noticeable roughness. Microhardness testing revealed little variation in green density distribution. Rheological measurement, however, showed th...