Cutting Tools Nitriding in Plasma Produced by a Fast Neutral Molecule Beam

Nitrogen plasma produced by a broad beam of fast neutral nitrogen molecules has been studied and used for cutting tools nitriding. The study results prove that fast molecules play a leading role in gas ionization in working vacuum chamber and current of ions produced by the molecules may be several times higher than the beam current. After 1-hour-long treatment microhardness of HSS cutting inserts rotating in reactive plasma and heated by 4-keV beam up to 500~$^{\circ}$C increased from 950HV to 1400HV and the mean radius of cutting edges decreased from $\sim $ 20 $\mu $m down to $\sim $ 17 $\mu $m.