Study On Interfacial Wettability And Mechanical Properties Of Al₂O₃/Cu Composites

Al₂O₃ ceramics are light,wear-resistant,high strength,chemically stable,and have a low coefficient of thermal expansion and electrical insulation.Metal Cu has excellent thermal conductivity and electrical conductivity,and has good toughness and high processability.Therefore,the Al₂O₃/Cu composites prepared by the component ratio and structural design have excellent comprehensive performance and have broad application prospects in the fields of rail transit,electronic packaging and electrical contacts.However,the interface wettability of Al₂O₃/Cu is poor,which severely limits the development and application of Al₂O₃/Cu composites.The preparation of the coating on the surface of the alumina ceramic can change the surface state of the ceramic,and it is expected to improve the interfacial wettability of Al₂O₃/Cu,thereby improving the overall performance of the composite.In this paper,the interfacial wettability of Al₂O₃/Cu is improved by impregnating the surface of alumina ceramic with CuO coating or CuO-Ni coating.On this basis,Al₂O₃/Cu/Al₂O₃ laminated composites were prepared and their flexural strength was studied.The three-dimensional network Al₂O₃/Cu composites were prepared by pressureless infiltration method to study the wear resistance.The research results are as follows:?1?The surface of Al₂O₃ ceramic was pretreated with CuO coating.When the coating amount of CuO was 0.48 mg/mm²,the pretreatment temperature was 1100°C,the wetting atmosphere was flowing argon,and the wetting temperature was 1250°C,the wetting angle of Al₂O₃/Cu is 26°,which is small;the interfacial reaction between CuO coating and Al₂O₃/Cu to form CuAlO₂ phase is the key to improve the wettability.?2?The surface of Al₂O₃ ceramics was pretreated with CuO-Ni coating,and the interfacial wettability of Al₂O₃/Cu was improved.When the pretreatment temperature was 1150°C,and the wetting temperature was 1200°C,the smaller wetting angle is 52°.?3?The Al₂O₃/Cu/Al₂O₃ laminated composite prepared by CuO coating modification can form a dense continuous CuAlO₂ transition layer at the interface to improve the bending strength of the composite;when the pretreatment temperature and wetting temperature are1100°C,the flexural strength is 410MPa;The Al₂O₃/Cu/Al₂O₃ laminated composite prepared by CuO-Ni coating modification has a bending strength of 425MPa when the pretreatment temperature is 1150°C and the wetting temperature is 1200°C;Compared with CuO coating,Al₂O₃/Cu/Al₂O₃ laminated composites modified by CuO-Ni coating has higher bending strength.?4?The ceramic preforms were pretreated by CuO/CuO-Ni coating,and the three-dimensional network Al₂O₃/Cu composites were prepared by pressureless infiltration method.The friction coefficient of the composites was stable and lower than the friction coefficient of pure Cu.The grinding performance is superior to the pure Cu material.