The invention relates to a nano
niobium aluminum
yttrium nitride /
amorphous silicon nitride dual-phase ultra-hard
coating and a deposition method thereof. The ultra-hard
coating is of a four-layer structure, wherein the innermost layer is a pure
niobium bonding layer, and thickness of the innermost layer is 0.05-0.5 micron; the secondary inner layer is a
niobium nitride transition layer, and the thickness of the secondary inner layer is 0.05-1 micron; the secondary outer layer is a gradient layer, component of the
niobium nitride is gradually reduced from inside to outside, and components of the niobium aluminum
yttrium nitride / the
silicon nitride are gradually increased, the thickness of the secondary outer layer is about 0.1-1.0 micron, and concentration on a stress interface can be prevented; and the outermost layer is composite wear-resistant layer of the niobium aluminum
yttrium nitride / the
silicon nitride, the thickness of the composite wear-resistant layer is 1-10 microns. The
total thickness of the
coating is 1.2-12.5 microns.
Binding force of the coating and a hard
alloy matrix reaches 70-105 N,
hardness of the coating is 40-60 GPa,
friction coefficient of the coating is 0.20-0.55,
antioxidant temperature of the coating is 750 DEG C or higher, and service life of a coated micro
drill or
milling cutter is prolonged by 4-8 times compared with that of an uncoated micro
drill or
milling cutter.