Cutter coating layer having nanometer columnar crystal for enhancing wear resistance and toughness

The invention discloses a cutter coating layer having a nanometer columnar crystal for enhancing wear resistance and toughness; and the wear resistance and the impact resistance are prominently improved through optimizing the grain size and the microstructure. The improved coating layer comprises the nanometer columnar crystal; and the control to the grain size and shape is guaranteed through adopting CH4, C2H6, C2H4, C2H2, N2 and CH3CN to serve as the composition of carbon and nitrogen sources. The composition ratio of all gases is necessarily and carefully controlled so as to maintain the structure of the nanometer columnar crystal. Preferably, the grain size of the columnar crystal is 50-150 nm, and the length-width ratio is greater than 10. The cutter coating layer overcomes the defects of weak wear resistance and impact resistance when grains of the columnar crystal of an MT-TiCN coating layer are thick, and overcomes the defect that a fine MT-TiCN coating layer is easy to form an isometric crystal to result in reduced wear resistance. The cutter coating layer has excellent toughness and good wear resistance, and has excellent cutting performance in the cutting of such materials as steel, cast iron and stainless steel.