Research On Preparation And Milling Performance Of AlTiN/AlCrN Coated Cemented Carbide Milling Cutter

The development of advanced coating tools is the need of the development of modern manufacturing industry.As a representative of the excellent tool coating,it is significant of researching the failure law of AlTiN/AlCrN coating on milling 420 die steel.It helps evaluating the milling performance of the coated milling cutter accurately and effectively,providing an accurate and reliable basis for the selection of reasonable coating and the development of new coating for coated milling cutter,also a strong support for the practical application of coating and the acceleration of its industrialization.A new AlTiN/AlCrN coated cemented carbide milling cutter was developed and manufactured to mill 420 die steel and this paper focused on its failure law comparing to another two coated cemented carbide milling cutter through characterizing the coating quality,cutting process,microstructure and composition by Vivtorinox hardness tester,Rockwell hardness tester,film adhesion strength scratch tester,surface profiler,ultra-depth microscope,SEM&EDS and so on.The below are the main studies and results:(1)Studied on mechanical properties of the three kinds of YG10 cemented carbide X/Y/Z and chose X,with a bending strength of 4300 N/mm,as the matrix.And a new milling cutter was developed and manufactured with a 6° rake angle and a 8° clearance angle of circumferential cutting edge,a 2° rake angle and a 6° clearance angle major cutting edge,a 30° helix angle and a 2° inclination angle.The single AlTiN coating,single AlCrN coating and AlTiN/AlCrN doublelayer composite coatings were deposited by multi arc ion plating method and compared and analysised by experiment.The AlTiN/AlCrN coating,with a 0.09 ?m Ra and a 3063.09 HV0.05 Vickers hardness,was not broken to expose the maxtri in the scratch test and indentation test,showing a good adhesion,uniform quality and suitable thickness to be the chosen coating.(2)The coating quality,microstructure,properties and chemical composition of the self-manufactured AlTiN/AlCrN doublelayer composite coating milling cutter and other brands of single AlTiN coated milling cutter and AlTiN/Al CrN multilayer composite coating milling cutter were studied comparatively.The average roughness value Ra of the three cutters' coatings was about 0.83?m,the water contact angle about 80°,the oil contact angle about 50°.The Rockwell hardness of the three cutters' matrices was about 87 HRA.The value of film-substrate cohesion,from large to small,was arranged in AlTi N coating,AlTiN/AlCrN multilayer composite coating,AlTiN/AlCrN doublelayer composite coating and the matrix of AlTiN/AlCrN multilayer composite coating proved to be brittle.(3)Based on the 420 die steel,the milling performance of the three kinds of milling cutters was characterized by end milling and edge milling separately.The cutting life of self-manfactured AlTiN/AlCrN doublelayer composite coating milling cutter was in the middle of the three with the best processing quality.In the end cutting,the self-manufactured AlTiN/AlCrN dobulelayer composite coating milling cutter's flank face wear was a hard point wear.While another two had a diffusion wear in addition.In the edge cutting,the self-manufactured AlTiN/AlCrN dobulelayer composite coating milling cutter's flank face wear was a hard point wear and the rake face an adhesive wear.While another two had a diffusion wear in the flank face wear in addition.