A series of metal cutting experiments was performed on a CNC lathe to evaluate the performance of various coatings on different tool substrates. The workpiece material was plain medium carbon steel and the cutting too...A series of metal cutting experiments was performed on a CNC lathe to evaluate the performance of various coatings on different tool substrates. The workpiece material was plain medium carbon steel and the cutting tool materials were carbide and cermet inserts coated with various single as well as multilayer coatings. Machining was done under various cutting conditions of speed and feed-rate, and for various durations of Cutting. The output parameters studied were the cutting forces (axial, radial and tangential), the surface roughness of the workpiece, as well as the tool wear (crater and flank wear). From these results, the performances of the various cutting inserts are evaluated and compared. Results show that cutting forces are significantly lower when using coated cermets than when using coated carbides although different coatings on the same substrate also result in different cutting forces. However, there is less difference in the surface roughness of the finished workpiece for the various coatings and substrates.展开更多
Based on the principle of Statistical Energy Analysis (SEA) for non-conservatively coupled systems under general excitations, relationship between noise radiated from and excitations on coupled complex structures is s...Based on the principle of Statistical Energy Analysis (SEA) for non-conservatively coupled systems under general excitations, relationship between noise radiated from and excitations on coupled complex structures is studied, which lays a foundation for the determination of noise/vibration energy by evaluation of exciting forces, and from that the quantitative analysis of the effects of an excitation on sound power from a sub-structure can be done. With extending of the relationship to the study of cutting noise, regression analysis method for evaluating the effects of cutting process on machine tool noise is established. Results show that cutting process has generally negligible effects on machine tool noise, and there is no apparent difference between machine tool noise in cutting condition and in idle one.展开更多
文摘A series of metal cutting experiments was performed on a CNC lathe to evaluate the performance of various coatings on different tool substrates. The workpiece material was plain medium carbon steel and the cutting tool materials were carbide and cermet inserts coated with various single as well as multilayer coatings. Machining was done under various cutting conditions of speed and feed-rate, and for various durations of Cutting. The output parameters studied were the cutting forces (axial, radial and tangential), the surface roughness of the workpiece, as well as the tool wear (crater and flank wear). From these results, the performances of the various cutting inserts are evaluated and compared. Results show that cutting forces are significantly lower when using coated cermets than when using coated carbides although different coatings on the same substrate also result in different cutting forces. However, there is less difference in the surface roughness of the finished workpiece for the various coatings and substrates.
文摘Based on the principle of Statistical Energy Analysis (SEA) for non-conservatively coupled systems under general excitations, relationship between noise radiated from and excitations on coupled complex structures is studied, which lays a foundation for the determination of noise/vibration energy by evaluation of exciting forces, and from that the quantitative analysis of the effects of an excitation on sound power from a sub-structure can be done. With extending of the relationship to the study of cutting noise, regression analysis method for evaluating the effects of cutting process on machine tool noise is established. Results show that cutting process has generally negligible effects on machine tool noise, and there is no apparent difference between machine tool noise in cutting condition and in idle one.
