Low cobalt(Co)WC hard materials were prepared using vacuum sintering.The influences of Co content on the sintering densification behavior,grain growth characteristics,microstructure and mechanical properties of WC har...Low cobalt(Co)WC hard materials were prepared using vacuum sintering.The influences of Co content on the sintering densification behavior,grain growth characteristics,microstructure and mechanical properties of WC hard material were studied.The experimental results show that the addition of a small amount of Co significantly promotes the densification and reduces the sintering temperature.Meantime,the abnormal growth of WC grains was observed.When the sintering temperature is 1300℃and the content of Co is less than 1.0wt%,densed WC/Co hard material with fine grains is obtained.When the content of Co is 1wt%,the relative density,Vickers hardness,and flexural strength of WC material are 98.76±0.17%,24.23±0.41 GPa,and 1376±67 MPa,respectively.When the Co content is 0.25wt%and 0.5wt%,the optimal sintering temperature of the sample is 1350℃.Among them,the relative density,hardness,and flexural strength of WC-0.5wt%Co are 98.79±0.15%,23.44±0.38 GPa,and 1233±85 MPa,respectively.展开更多
WC-10Co nanocrystalline composite powders prepared by spray pyrogenation-continuous reduction and carburization technology were consolidated by vacuum sintering plus hot isostatic pressing （HIP）. Influences of carbo...WC-10Co nanocrystalline composite powders prepared by spray pyrogenation-continuous reduction and carburization technology were consolidated by vacuum sintering plus hot isostatic pressing （HIP）. Influences of carbon content on properties and microstructure of ultrafine WC-10Co cemented carbide were investigated. The results show that the relative density of the ultrafine WC-10Co cemented carbides can reach 99.72%, and the transverse rupture strength （TRS） was higher than 3 890 MPa, Rockwell A hardness （HRA） was higher than 92.5, the average grain size was less than 460 nm, when carbon content in nanocrystalline composite powder was 5.54wt% and the ball-milled time was 48 hours, ultrafine WC-10Co cemented carbide with excellent properties and homogeneous microstructure was obtained.展开更多
Inconel 625+WC composite coatings were prepared on the surface of 2Cr13 steel by laser cladding.The microstructure,microhardness and corrosion resistance of the composite coatings with different WC contents were inves...Inconel 625+WC composite coatings were prepared on the surface of 2Cr13 steel by laser cladding.The microstructure,microhardness and corrosion resistance of the composite coatings with different WC contents were investigated in detail.The results show that the phase compositions of the composite coatings are mainly y-(Ni,Fe)and various carbides.The content of WC has a significant effect on the microstructure of the cladding layers.When the WC content is 10 wt%and 15 wt%,the cladding layer has developed columnar dendrites.However,the 20 wt%WC coating is mainly composed of cellular dendrites and columnar dendrites.With the increase in WC content,the average hardness of the composite coating gradually increases.The average hardness of 20 wt%WC coating is the highest(HV_(1)536.98),which is a factor of2.64 greater than that of the 2 Cr13 steel matrix.Electrochemical results show that all the composite coatings have better corrosion resistance than 2 Cr13 steel in 0.5 mol·L^(-1) HCl solution.The composite coating with 10 wt%WC has the best corrosion resistance,its corrosion potential(E_(corr))is 0.78806 V higher than that of 2 Cr13 steel,and the corrosion current density(I_(corr))is only 0.86%that of 2 Cr13 steel.展开更多
基金Funded by the National Natural Science Foundation of China(No.52022072)the Key Research and Development Plan of Jiangxi Province(No.2020ZDYFB0017)。
文摘Low cobalt(Co)WC hard materials were prepared using vacuum sintering.The influences of Co content on the sintering densification behavior,grain growth characteristics,microstructure and mechanical properties of WC hard material were studied.The experimental results show that the addition of a small amount of Co significantly promotes the densification and reduces the sintering temperature.Meantime,the abnormal growth of WC grains was observed.When the sintering temperature is 1300℃and the content of Co is less than 1.0wt%,densed WC/Co hard material with fine grains is obtained.When the content of Co is 1wt%,the relative density,Vickers hardness,and flexural strength of WC material are 98.76±0.17%,24.23±0.41 GPa,and 1376±67 MPa,respectively.When the Co content is 0.25wt%and 0.5wt%,the optimal sintering temperature of the sample is 1350℃.Among them,the relative density,hardness,and flexural strength of WC-0.5wt%Co are 98.79±0.15%,23.44±0.38 GPa,and 1233±85 MPa,respectively.
基金the National Natural Science Foundation of China (No.50502026)the Youth Science Plan for Light of the Morning Sun of Wuhan City(No.200750731270)Key Project for the Science & Technology Research Department,Chinese Ministry of Education (No.105123)
文摘WC-10Co nanocrystalline composite powders prepared by spray pyrogenation-continuous reduction and carburization technology were consolidated by vacuum sintering plus hot isostatic pressing （HIP）. Influences of carbon content on properties and microstructure of ultrafine WC-10Co cemented carbide were investigated. The results show that the relative density of the ultrafine WC-10Co cemented carbides can reach 99.72%, and the transverse rupture strength （TRS） was higher than 3 890 MPa, Rockwell A hardness （HRA） was higher than 92.5, the average grain size was less than 460 nm, when carbon content in nanocrystalline composite powder was 5.54wt% and the ball-milled time was 48 hours, ultrafine WC-10Co cemented carbide with excellent properties and homogeneous microstructure was obtained.
基金financially supported by the Natural Science Foundation of Inner Mongolia Autonomous Region(No.2017MS(LH)0518)。
文摘Inconel 625+WC composite coatings were prepared on the surface of 2Cr13 steel by laser cladding.The microstructure,microhardness and corrosion resistance of the composite coatings with different WC contents were investigated in detail.The results show that the phase compositions of the composite coatings are mainly y-(Ni,Fe)and various carbides.The content of WC has a significant effect on the microstructure of the cladding layers.When the WC content is 10 wt%and 15 wt%,the cladding layer has developed columnar dendrites.However,the 20 wt%WC coating is mainly composed of cellular dendrites and columnar dendrites.With the increase in WC content,the average hardness of the composite coating gradually increases.The average hardness of 20 wt%WC coating is the highest(HV_(1)536.98),which is a factor of2.64 greater than that of the 2 Cr13 steel matrix.Electrochemical results show that all the composite coatings have better corrosion resistance than 2 Cr13 steel in 0.5 mol·L^(-1) HCl solution.The composite coating with 10 wt%WC has the best corrosion resistance,its corrosion potential(E_(corr))is 0.78806 V higher than that of 2 Cr13 steel,and the corrosion current density(I_(corr))is only 0.86%that of 2 Cr13 steel.
