Research On Interface Bonding Properties Of Graphene-Doped TiAlSiN Coated Carbide Tools

TiAlSiN coated carbide tools have high hardness,wear resistance and high temperature oxidation resistance,which widely used in mechanical processing such as auto parts and precision molds.Graphene has excellent properties such as high strength,structural stability,flexibility and thermal conductivity.It's ideal material for improving properties of composite materials.At present,there were few studies on graphene-doped TiAlSiN coated carbide tools at home and abroad.Based on first-principles,this paper studies interface bonding properties of graphene-doped TiAlSiN coated WC-Co carbide tools from microscopic atomic scale.It has important theoretical and practical significance for revealing interface combination situation and optimizing interface structure.The interface bonding properties of TiAlSiN/WC-Co was studied.The interface models of TiAlSiNAl/WC-Co,TiAlSiNSi/WC-Co and TiAlSiNN/WC-Co were constructed.The adhesion work and fracture toughness were calculated,and charge density difference,state density and charge population were analyzed.The results show that TiAlSiNsi/WC-Co has the largest adhesion work(9.530J·m-2).Si forms strong chemical bonds with Co,so the interface is the most stable,and interface bonding preoperties is strongest.TiAlSiNsi/WC-Co has the smallest adhesion work(3.280J·m-2).Because of poor N-Co bonding,the interface is the most unstable,and interface bonding preoperties are the weakest.The interface bonding properties of TiAlSiN/WC-Co doped graphene in matrix was studied.Based on the most stable TiAlSiNsi/WC-Co and unstable TiAlSiNN/WC-Co interface models,TiAlSiNsi/WC/msGR/Co,TiAlSiNN/WC/msGR/Co,TiAlSiNSi/WC/acGR/Co,TiAlSiNN/WC/-acGR/Co,TiAlSiNsi/WC/zzGR/Co and TiAlSiNN/WC/zzGR/Co which matrix doped intrinsic graphene were constructed.And TiAlSiNsi/WC/svGR/Co,TiAlSiNN/WC/SVGR/Co,TiAlSiNSi/WC/tdGR/Co and TiAlSiNN/WC/tdGR/Co which matrix doped defective graphene were constructed.The adhesion work was calculated and electronic structure was analyzed.The results show that combination of matrix and graphene main surface improves interface bonding preoperties of TiAlSiN/WC-Co.TiAlSiNsi/WC/msGR/Co has the highest adhesion work.The C atoms of graphene bond with Co and W atoms in matrix,and Co atoms bond well with Al,Si and N atoms,with the strongest interface bonding property.Bonding between matrix and graphene border reduces interface bonding preoperties of TiAlSiN/WC-Co.Adhesion work of TiAlSiNSi/WC/acGR/Co is the lowest.Transfer charge of Al,Si and N atoms at interface is small,and the bonding is poor.The interface bonding property of TiAlSiN/WC-Co was decreased by doping graphene in matrix.TiAlSiNN/WC/tdGR/Co interface has the lowest adhesion work and the weakest bonding preoperty.The interface bonding properties of TiAlSiN/WC-Co doped graphene in coating was studied.The TiAlSiN/msGR/TiAlSiNsi/WC-Co,TiAlSiN/msGR/TiAlSiNN/WC-Co,TiAlSiN/acGR/Ti-AlSiNSi/WC-Co,TiAlSiN/acGR/TiAlSiNN/WC-Co,TiAlSiN/zzGR/TiAlSiNsi/WC-Co,TiAlSiN/zzGR/TiAlSiNN/WC-Co,TiAlSiN/svGR/TiAlSiNsi/WC-Co,TiAlSiN/svGR/TiAlSiNN-/WC-Co,TiAlSiN/tdGR/TiAlSiNsi/WC-Co and TiAlSiN/tdGR/TiAlSiNN/WC-Co were constructed.Adhesion work was calculated and electronic structure was analyzed.The results show When coating is combined with graphene main surface,TiAlSiN/msGR/TiAlSiNN/WC-Co has the highest adhesion work and strongest bonding preoperties.Combination of coating and graphene border reduces interface bonding preoperties of TiAlSiN/WC-Co,of which TiAlSiN/zzGR/TiAlSiNsi/WC-Co has the lowest adhesion work and weakest bonding preoperties.When coating doped defective graphene,only adhesion work of TiAlSiN/svGR/TiAlSiNN/WC-Co interface increases,and interface bonding preoperties improves.When matrix and coating doped simultaneously graphene,TiAlSiN/msGR/TiAlSiNN/WC/msGR/Co and TiAlSiN/svGR/TiAlSiNN/WC/msGR/Co improve TiAlSiNN/WC-Co interface bonding preoperties.The interface bonding properties of TiAlSiN/WC-Co doped graphene between coating and matrix was studied.TiAlSiNsi/msGR/WC-Co,TiAlSiNN/msGR/WC-Co,TiAlSiNsi/acGR/WC-Co,TiAlSiNN/acGR/WC-Co,TiAlSiNSi/zzGR/WC-Co,TiAlSiNN/zzGR/WC-Co,TiAlSiNsi/-svGR/WC-Co,TiAlSiNN/svGR/WC-Co,TiAlSiNSi/tdGR/WC-Co and TiAlSiNN/tdGR/WC-Co were constructed.The adhesion work was calculated and electronic structure was analyzed.The results show that combination of the interface and graphene main surface improves TiAlSiNN/WC-Co interface bonding preoperties,and decreases TiAlSiNsi/WC-Co interface bonding preoperties.Combination of the interface and graphene border reduces TiAlSiN/WC-Co interface bonding preoperties.Adhesion work of TiAlSiNN/acGR/WC-Co is the lowest,and electron overlap between TiAlSiN and Co atoms is less.The chemical bond is weak,and interface bonding preoperties is the weakest.When the interface doped defective graphene,only strong chemical bonds are formed between atoms at TiAlSiNN/avGR/WC-Co interface,and the interface bonding preoperties is improved.Adhesion work of graphene-doped TiAlSiN/WC-Co interface model wae comprehensively analyzed.The results show that:for the most stable TiAlSiNsi/WC-Co interface,doping msGR in matrix can improve interface bonding preoperties.For the most unstable TiAlSiNN/WC-Co interface,doping msGR in matrix,doping msGR or svGR in coating,and doping msGR or svGR at the interface can improve interface bonding preoperties.