Microstructure and thermal shock behaviour of BN composites

Investigation of the Physical and Mechanical Properties of Hot‐Pressed Boron Nitride/Oxide Ceramic Composites

“…The micrograph shows "stacked" grains of boron nitride with characteristic microcracking observed between basal planes. 9 The oxide phases formed during hotpressing are the dark regions located between the BN grains. No amophous regions were observed using selected area diffraction techniques.…”

“…These improvements may be due to microcracks that exist between basal planes in h-BN. [9][10][11] h-BN can also be used as a weak interface between layers 12 or filaments 13,14 of silicon nitride. However, recent research has shown that interfaces created with BN powders often include a secondary phase.…”

Mechanical Properties and Thermal Shock Resistance of Alumina/Hexagonal Boron Nitride Composite Refractories

“…Meanwhile, crack deflection occurred at the boundaries of flaky h-BN due to the weaker bonding. [14,38] Furthermore, as the BN content increased, the AP increased (Table I). The pores resulted in a weak interface in the refractories, indicating that when cracks propagate and come across to the pores, crack blunting occurred.…”

Electrical and thermal properties of silicon carbide–boron nitride composites prepared without sintering additives

“…Boron nitride (BN) ceramics have demonstrated advantages in terms of thermal shock resistance as well as machinability [10,11]. Hexagonal BN (h-BN) is also known to have a high electrical resistivity as well as a low thermal expansion coefficient [10]. These properties of BN have led to its use in a variety of specialized areas including crucibles for molten metals and the sintering of nitride ceramics, break rings for horizontal continuous casting of steel, and thermal protection tubes.…”

“…Rigid SiC ceramics with a high thermal conductivity and chemical stability have various industrial applications such as in mechanical seals, bearings, heat-sink plates, automobile and gas-turbine components, and protective walls for nuclear reactors. Boron nitride (BN) ceramics have demonstrated advantages in terms of thermal shock resistance as well as machinability [10,11]. Hexagonal BN (h-BN) is also known to have a high electrical resistivity as well as a low thermal expansion coefficient [10].…”