High speed machining has received an important interest because it leads to an increase of productivity and a better workpiece surface quality. However, at high cutting speeds, the tool wear increases dramatically due...High speed machining has received an important interest because it leads to an increase of productivity and a better workpiece surface quality. However, at high cutting speeds, the tool wear increases dramatically due to the high temperature at the tool-workpiece interface. Tool wear impairs the surface finish and hence the tool life is reduced. That is why an important objective of metal cutting research has been the assessment of tool wear patterns and mechanisms. In this paper, wear performances of PCBN tool, ceramic tool, coated carbide tool and fine-grained carbide tool in high speed face milling were presented when cutting cast iron, 45# tempered carbon steel and 45# hardened carbon steel. Tool wear patterns were examined through a tool-making microscope. The research results showed that tool wear types differed in various matching of materials between cutting tool and workpiece. The dominant wear patterns observed were rake face wear, flank wear, chipping, fracture and breakage. The main wear mechanisms were mechanical friction, adhesion, diffusion and chemical wear promoted by cutting forces and high cutting temperature. Hence, the important considerations of high speed cutting tool materials are high heat-resistance and wear-resistance, chemical stability as well as resistance to failure of coatings. The research results will be great benefit to the design and the selection of tool materials and control of tool wear in high-speed machining processes.展开更多
In machining titanium alloys, cutting tools generally wear out very rapidlybecause of the high cutting temperature resulted from the low thermal conductivity and density ofthe work material. In order to increase the t...In machining titanium alloys, cutting tools generally wear out very rapidlybecause of the high cutting temperature resulted from the low thermal conductivity and density ofthe work material. In order to increase the tool life, it is necessary to suppress the cutting heatas much as possible by applying an abundant amount of coolant, but this will entail serioustechno-environmental and biological problems. To study the performance and avoid these limitations,a PVD-coated insert was used to the dry face mill of (alpha + beta) titanium alloys. As a result itwas found that the inserts exhibit an excellent cutting performance at low cutting speeds and feedrates, and there is no significant difference in the dominant insert failure mode between the wetand dry cutting in discontinuous cutting.展开更多
文摘High speed machining has received an important interest because it leads to an increase of productivity and a better workpiece surface quality. However, at high cutting speeds, the tool wear increases dramatically due to the high temperature at the tool-workpiece interface. Tool wear impairs the surface finish and hence the tool life is reduced. That is why an important objective of metal cutting research has been the assessment of tool wear patterns and mechanisms. In this paper, wear performances of PCBN tool, ceramic tool, coated carbide tool and fine-grained carbide tool in high speed face milling were presented when cutting cast iron, 45# tempered carbon steel and 45# hardened carbon steel. Tool wear patterns were examined through a tool-making microscope. The research results showed that tool wear types differed in various matching of materials between cutting tool and workpiece. The dominant wear patterns observed were rake face wear, flank wear, chipping, fracture and breakage. The main wear mechanisms were mechanical friction, adhesion, diffusion and chemical wear promoted by cutting forces and high cutting temperature. Hence, the important considerations of high speed cutting tool materials are high heat-resistance and wear-resistance, chemical stability as well as resistance to failure of coatings. The research results will be great benefit to the design and the selection of tool materials and control of tool wear in high-speed machining processes.
文摘In machining titanium alloys, cutting tools generally wear out very rapidlybecause of the high cutting temperature resulted from the low thermal conductivity and density ofthe work material. In order to increase the tool life, it is necessary to suppress the cutting heatas much as possible by applying an abundant amount of coolant, but this will entail serioustechno-environmental and biological problems. To study the performance and avoid these limitations,a PVD-coated insert was used to the dry face mill of (alpha + beta) titanium alloys. As a result itwas found that the inserts exhibit an excellent cutting performance at low cutting speeds and feedrates, and there is no significant difference in the dominant insert failure mode between the wetand dry cutting in discontinuous cutting.
