Boron carbonitride powder and method for producing same, powder composition, boron nitride sintered compact and method for producing same, and complex and method for producing same

A powder composition comprising a lump particle of boron carbonitride having micropores and a sintering aid, wherein a specific surface area of the powder composition is 12 m2/g or more.

A boron nitride sintered body comprising primary particles of boron nitride,

• wherein, in a cross-sectional image including 100 or more particles observed at a magnification of 500 times with a scanning electron microscope, an average number of lump particles having a particle size of 30 μm or more formed by aggregation of the primary particles is 3 or less.

A method for manufacturing a boron carbonitride powder, the method comprising:

• a nitriding step of firing a raw material powder containing boron carbide in a nitrogen-containing atmosphere to obtain a fired product containing boron carbonitride;
• and
• a pulverizing step of pulverizing the fired product to obtain a boron carbonitride powder having a specific surface area of 12 m2/g or more.