Correlations between milling conditions and iron contamination, microstructure and hardness of mechanically alloyed cubic BN particle reinforced NiCrAl matrix composite powders

► Under optimized conditions, the iron contamination decreased from 10.8 to 2.2 wt.%. ► NiCrAl crystals were refined to be ∼35 nm with high dislocation density of ∼1016 m−2. ► By 'step-fashion' method, NiCrAl can incorporate as many as 40 vol.% of cBN. ► Embedded cBN dispersoids facilitated the multiplication of dislocations. ► Composite powders with cBN uniformly distributed and hardness of 1150 HV were gained.