Investigation Of Deposition Processes And Cutting Properties Of (Ti,Al,Cr)N-coated HSS Cutting Tools

The preparation of(Ti,Al,Cr)N quaternary constituent hard nitride composite films by introducing Cr in Ti Al N hard film. Composition gradient film was formed by changing the nitrogen partial pressure during the deposition process. The performance of the(Ti,Al,Cr)N films deposited at different three bias are compared with each other and the optimization of process is reached. The optimal deposition process is then applied to the preparation of the(Ti,Al,Cr)N-coated drills and milling cutters. Through the cutting experiments, it is concluded that the(Ti,Al,Cr)N-coated cutting tools raise cutting performance and prolong service life.The(Ti,Al,Cr)N films are deposited on M42 HSS(high cobalt content) using physical vapor deposition technology. The combination of TiAl alloy target and pure Cr target is adopted in the depositions. The microstructure and properties of the(Ti,Al,Cr)N films change with changing bias voltages. The(Ti,Al,Cr)N-coated samples required for the performance test are then obtained. The surface morphology, hardness, adhesion, thermal shock resistance and friction and wear performance are tested and analyzed. The results showed that under the deposition negative bias 150 V the(Ti,Al,Cr)N film reached hardness value of HV3400, film/substrate adhesion larger than 146 N and thermal shock cycles of 8 times. On this basis, the optimal deposition process parameters were determined and applied to the preparation of(Ti,Al,Cr)N-coated cutting tools.The 45 # steel was adopted as material for actual cutting test and the contrast analysis on the cutting performances was carried out. By changing cutting parameters, the test is divided into five groups and each group underwent three stages of testing. The analysis of cutting performance of the(Ti,Al,Cr)N-coated cutting tools and the uncoated tools, also with the worn surface morphology at the stages are completed. In every stage the flank wear width of the cutting tool is measured to quantitively describe the wear of coated cutting tool and cutting tool without coatingThe analysis and comparison show that the(Ti,Al,Cr)N film has a good adhesion with high speed steel cutting tools and improves cutting performance. Compared with uncoated cutting tools, the(Ti,Al,Cr)N-coated drill and milling cutter significantly reduce, The flank wear significantly mitigate. The abrasion resistance is increased significantly. The cutting prerformances and service life of the(Ti,Al,Cr)N-coated cutting tools are both improved obviously. The(Ti,Al,Cr)N-coated drill prolongs service life by 4-5 times.The(Ti,Al,Cr)N-coated milling cutter prolongs service life by 3 times.