Theoretical Calculation And Analysis Of Material Properties Of Rare Earth Cemented Carbide Tools

Cemented carbide has a series of excellent properties,such as high hardness,wear resistance,good strength and toughness,so it is widely used in tool materials.With the wide application of cemented carbide,the performance of traditional cemented carbide can not meet the current demand.The addition of rare earth elements can strengthen the comprehensive performance of WC-Co cemented carbide.Based on the previous experiments and research results,the structural model of WC-Co was established by using the first principle software Materials Studio(MS),and the model was doped with rare earth element Y.The CASTEP module in MS software was used to calculate the density functional theory of each model.According to the calculat ed elastic constants and thermodynamic parameters,the influence of Y element doping on the elastic and thermodynamic properties of WC-Co was analyzed.It was found that the elastic properties of tungsten cobalt alloy doped with rare earth elements are significantly improved.As we all know,grain size is one of the important reasons affecting the comprehensive properties of cemented carbide,so the research on grain size of cemented carbide is particularly important.The interface adhesion work and interface energy are calculated from the interface binding related energy obtained by CASTEP,so as to analyze the influence of doping rare earth element Y on the interface properties.The grain refinement mechanism of cemented carbide was studied by the relationship between grain size and interface properties and combined with electronic characteristics.Then,the cellular automata under Matlab was used to simulate the grain growth process of cemented carbide during sintering before and after doping Y element,so as to verify our calculation and analysis results.The results show that the grain size of W-Co alloy decreases obviously after doping rare earth elements.Because the main failure reason of cemented carbide is fracture and wear,the research on the fracture and wear resistance of cemented carbide is essential.By calculating the interface properties and elastic properties,the fracture and wear resistance of cemented carbide tools before and after doping rare earth elements were analyzed,and the cemented carbide materials with successful sintering were used to carry out the relevant experiments of cemented carbide wear and fracture to verify it.The influence of Y doping on the electronic properties of cemented carbide was used to study the mechanism of tool wear and fracture.Finally,the effect of Y element on the melting point of cemented carbide tools is studied by calculating the specific heat capacity and Debye temperature of the two systems.The results show that the fracture resistance and wear resistance of W-Co alloy doped with rare earth elements are strengthened.Through our research,we can judge whether the cemented carbide WC Co doped with a small amount of rare earth elements can effectively improve its comprehensive properties.This provides an important reference for other researchers.