In this paper,the microstructure of WC-Co alloys with and without nano-additives was characterized by scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.The hardness and fracture toughness...In this paper,the microstructure of WC-Co alloys with and without nano-additives was characterized by scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.The hardness and fracture toughness was tested by using a Vickers hardness tester and a universal testing machine.The cutting test was carried out at different feed velocities（250 r/min and 320 r/min）,and the contact pairs are cutting tools and 45# steel bars.Results showed that the hardness and fracture toughness of WC-Co cemented carbides with nano-additives are higher than that of WC-Co cemented carbides without nano-additives,and they are increased 10.21% and 19.69%,respectively.The flank worn width and crater width of cutting tools decrease greatly with the addition of nano-additives.For the nano-modified specimen with WC grain size of 7 μm,both the flank worn width and crater width are the minimum after the cutting process.And there are little built-up layers and some pile-up regions on the flank face leading to high cutting performance for the nano-modified cemented carbides.There are some melted regions on the flank face of cutting tools without nano-additives,and the WC grains on the cross section of alloys without nano-additives show severe fragmentation.The wear type of WC-Co is flank wear,and the wear mechanism is abrasive,adhesion and oxidation wear.展开更多
基金supported by the Program of Excellent Team at Harbin Institute of Technology
文摘In this paper,the microstructure of WC-Co alloys with and without nano-additives was characterized by scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.The hardness and fracture toughness was tested by using a Vickers hardness tester and a universal testing machine.The cutting test was carried out at different feed velocities（250 r/min and 320 r/min）,and the contact pairs are cutting tools and 45# steel bars.Results showed that the hardness and fracture toughness of WC-Co cemented carbides with nano-additives are higher than that of WC-Co cemented carbides without nano-additives,and they are increased 10.21% and 19.69%,respectively.The flank worn width and crater width of cutting tools decrease greatly with the addition of nano-additives.For the nano-modified specimen with WC grain size of 7 μm,both the flank worn width and crater width are the minimum after the cutting process.And there are little built-up layers and some pile-up regions on the flank face leading to high cutting performance for the nano-modified cemented carbides.There are some melted regions on the flank face of cutting tools without nano-additives,and the WC grains on the cross section of alloys without nano-additives show severe fragmentation.The wear type of WC-Co is flank wear,and the wear mechanism is abrasive,adhesion and oxidation wear.
