Cubic boron nitride particle population with highly-etched particle surface and high toughness index

A method for producing an etched monocrystalline cubic boron nitride particle population, comprising:

• blending an amount of from 20 wt. % to 90 wt. % of a reactive zirconium powder with an amount of from 10 wt. % to 80 wt. % of a plurality of monocrystalline cubic boron nitride particles based on a total amount of a blended mixture;
• compressing the blended mixture to form a compressed blended mixture;
• subjecting the compressed blended mixture to a temperature and a pressure of 3 gigapascals to cause etching of the plurality of monocrystalline cubic boron nitride particles by reaction of the plurality of monocrystalline cubic boron nitride particles with the reactive zirconium powder, such that boron nitride remains in a cubic phase and does not convert to hexagonal boron nitride and a plurality of etched monocrystalline cubic boron nitride particles are formed;
• and
• recovering the plurality of etched monocrystalline cubic boron nitride particles free of the boron nitride being in a hexagonal phase from the compressed blended mixture to form the etched monocrystalline cubic boron nitride particle population,
• wherein a toughness index of the plurality of etched monocrystalline cubic boron nitride particles is 10 to 20 points lower than non-etched, non-rough cubic boron nitride particles with the same chemical composition, crystal structure, and shape.