Simulation Of Phase Interface Wettability And Binding Energy Of SiCp/Al Matrix Composites

Silicon carbide particle-reinforced aluminum matrix composites（SiCp/Al matrix composites）,because of their excellent physicochemical properties,have shown extremely promising applications in aerospace,transportation manufacturing,advanced weapons development and manufacturing,precision electronic components manufacturing,electronic packaging,etc.The interfacial bonding strength of SiCp/Al matrix composites is an important factor affecting their physicochemical properties.In this paper,we study the interfacial bonding and wettability of the matrix material Al and the reinforcement particles SiC from a microscopic perspective,and investigate the influence of the doping of alloying elements（Ni,Cu）on the wettability behavior and interfacial bonding properties of the matrix material Al on the surface of the reinforcement particles SiC.The main studies include:（1）Optimizing the cell structure models of metallic elements Al,Ni,Cu and reinforcement particles SiC from the atomic scale by choosing different density correlation generalization,truncation energy and k-point.The Al（Cu,Ni）（111）facets with the most stable surface structure and the lowest surface energy are selected to be interbonded with the SiC（0001）-b facets.SiC（0001）-b/Al（111）-Top was determined as the most stable bonding orientation.It was determined by calculating the cut-off energy and the separation work that the post-tensile fracture preferentially occurs at the near-interfacial location inside the Al matrix in SiC/Al when SiC（0001）-b/Al（111）is well bonded,and a thin Al layer may be attached to the SiC surface under ideal conditions.It was found that Al wets well on the SiC（0001）-b surface by the wetting behavior,and the wetting angles are all less than 90°,which is consistent with the experimental measurements.（2）Considering the generation of Al₄C₃ and Al C₃ impurity phases when Al is in contact with the SiC interface,the Al/Al₄C₃and Al/Al C₃interface bonding model and the wetting model were constructed,and it was found that the wetting angle of Al on the Al/Al₄C₃（and Al/Al C₃）surface was about 56°larger than that of Al on the SiC（0001）-b-Si surface at 50°,indicating that Al wets better on the SiC（0001）-b surface,and it also indicates that the presence of impurity phases Al₄C₃and Al C₃ hinders the Al wetting on the SiC surface.Combined with the state of the charges in the charge distribution diagram after stretching of the SiC/Al model,it shows that the presence of impurity phases does not reduce the bonding performance of Al and SiC,and the main influencing factor of the bonding strength is the strength of the Al material itself.（3）After the incorporation of Ni element,interfacial reaction will occur at high temperature and Al_xNi_y intermediate layer will be formed.To study the wetting of Al on the surface of Al_xNi_yintermediate layer,it is calculated that the introduction of Al_xNi_yintermediate layer makes the wetting angle decrease significantly,where Al Ni₃ is the intermediate layer,the bonding potential energy difference is the largest,indicating that Al Ni₃ has the best effect on the increase of wettability.Al_xNi_y intermediate After the addition of the dielectric layer,the tensile fracture location is still inside the Al matrix,indicating that the Al_xNi_yintermediate dielectric layer does not reduce the interfacial bonding ability.（4）After doping with Cu element,the Al_xCuy intermediate layer is formed,and comparing the wetting of Al/Al_xCu_y and Al/SiC surfaces,the wetting angle of Al on the Al_xCu_y surface is significantly smaller,while Al wets best on the Al Cu₄ surface,and the fracture location is still inside Al after stretching the Al/Al_xCu_ysystem.the Cu doping has the same effect on the interface The effect of Cu doping is similar to that of Ni,however,because the melting point of Cu itself is lower and the reaction temperature required for the formation of intermetallic compounds between Al and Cu is much lower than that of Al and Ni,the production cost of Cu doping is lower than that of Ni doping,while the melting point of Al and Ni forming intermetallic compounds is higher,and this system is suitable for higher temperature working conditions.