摘要
The main components of cemented carbides include tungsten carbide(WC) and cobalt(Co),of which their melting point and density vary widely.It is not suitable for preparing porous cemented carbides according to the preparation process of the ordinary porous metal.In the paper,the porous cemented carbide was prepared with coarse-grain and low-cobalt alloy by modifying its sintering process.The surface features were observed through the metallurgical microscope,scanning electron microscope and three-dimensional profile instrument.The friction characteristics of WC/GCr15 sliding couplings under the dry condition were evaluated with the adoption of a ball-on-disk tribometer.The experimental results show that the porosity of porous cemented carbides varies from 7.5%to 9.0%.Their density and hardness decrease slightly.The size and depth of pits on their surfaces of porous cemented carbides are not quite uniform,namely,the depth ranges from several microns to 32 urn,which can be used to store the particles.The friction coefficient of porous cemented carbides is lower than the dense ones,and the wear resistance accordingly increases.It can be indicated that porous structure may have exerted an important influence on the dry friction properties of cemented carbides.
The main components of cemented carbides include tungsten carbide(WC) and cobalt(Co),of which their melting point and density vary widely.It is not suitable for preparing porous cemented carbides according to the preparation process of the ordinary porous metal.In the paper,the porous cemented carbide was prepared with coarse-grain and low-cobalt alloy by modifying its sintering process.The surface features were observed through the metallurgical microscope,scanning electron microscope and three-dimensional profile instrument.The friction characteristics of WC/GCr15 sliding couplings under the dry condition were evaluated with the adoption of a ball-on-disk tribometer.The experimental results show that the porosity of porous cemented carbides varies from 7.5%to 9.0%.Their density and hardness decrease slightly.The size and depth of pits on their surfaces of porous cemented carbides are not quite uniform,namely,the depth ranges from several microns to 32 urn,which can be used to store the particles.The friction coefficient of porous cemented carbides is lower than the dense ones,and the wear resistance accordingly increases.It can be indicated that porous structure may have exerted an important influence on the dry friction properties of cemented carbides.
基金
financially supported by the Post Doctoral Funding of Jiangsu Province(1402045B)
the Key Research Project of Jiangxi Province Education Department(GJJ150619)
the Research Funding of Jiangxi University of Science and Technology(NSFJ2014-K20)
