Cutting Performance of WC-Co Alloys Modified by Nano-Additives

You Wang 1),Zhaoyi Pan 1),Chengbiao Wang 2),Xiaoguang Sun 1),Zhijian Peng 2) and Baolin Wang 2) 1) Laboratory of Nano Surface Engineering,Department of Materials Science,Harbin Institute of Technology,Harbin 150001,China 2) School of Engineering and Technology,China University of Geosciences,Beijing 100083,China

摘 要：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.

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