According to the principle of metal cutting, in the normal cutting, tool wear mainly include the following: after the blade surface wear and tear; Before the blade wear, namely crater wear; Before and after the blade surface wear at the same time.

Coating refers to the strength and toughness good cemented carbide and high speed steel (HSS) substrate on the surface, using the method of vapor deposition coated with a thin layer of abrasion resistance good refractory metal or non-metallic compounds, as a chemical barrier and thermal barrier coating, reduce the diffusion and chemical reaction between the cutter and workpiece, thereby reducing the crater wear. Coated tools have high surface hardness, wear resistance, stable chemical performance, good heat resistance to oxidation, low friction factor, and low thermal conductivity characteristics. As shown in figure for Mr. Kang barr chass coated tools (OerlikonBalzers) do with uncoated tool cutting state diagram.

Physical vapor deposition (PVD) is a kind of physical gas instead should growth method. Deposition process is under the condition of vacuum and low pressure gas discharge, namely in the process of low temperature plasma. Solid material, coating material source is after "evaporation and sputtering", in the generation and substrate surface properties completely different new solid state material coating. PVD coating material for TiN, TiCN, CrN, TiAlN, AlTiN, AlCrN, WC/C, the DLC and diamond elements, different application field, need to choose different coating material. The thickness of the coating are usually only a few microns, hardness is 2 to 5 times of steel. Mr. Kang barr chass (OerlikonBalzers) coating company invented the chromium element to replace titanium coating technology, and in 2004 launched a product called "BalinitAlcorna" single AlCrN coating. AlCrN coating of high hardness makes it under high heat load is still can keep the stable performance, the high speed cutting, dry (or must) dry application performance test results show that machining conditions, the coating of high hardness and wear resistance that can achieve HRC70 cutting material hardness.

Through shaft product material for the 49 crmo4, technical requirements for heat treatment: induction hardening effect the depth of hardening layer 5-7 mm, surface hardness 50 to 55 HRC, heart for conditioning group, 35-40 HRC hardness requirements. Analysis in theory can fully use the coated tools through shaft after heat cutting.

Chooses spline hob, at the ou rui kang barr chass (OerlikonBalzers) after coating process test. Process method is: the heat before grinding cylindrical - hot - rolling spline D C C area after straightening, after hot rolling spline B, after transferring the original rolling spline process and heat processing.

In the original cutting parameters unchanged (S = 250 r/minF = 13 m/min), processing noise is decreased obviously. For processing the product quality tracking, arbitrary sampling 10 pieces through spline shaft beating and M values change quantity, can be seen from the recorded data, application of coated tools after hot rolling cut through axis machining accuracy completely conform to the requirements of the drawings, the accuracy can cancel the deviation. M change quantity decreased after improved and flange assembly back gap change amount, so as to improve the assembly accuracy.