Preparation Of Al₂O₃/Cu Composites With Three-Dimensional Net Structure By 3D Printing Template Technology

The three-dimensional network structure Al₂O₃/Cu composite material has broad application prospects in the field of electronic packaging and electrical contact because of its high hardness and high wear resistance of Al₂O₃ and excellent electrical conductivity of Cu.It is expected to replace the traditional Cu alloy as a new generation of touch.Head material.How to precisely control the distribution and structure of alumina phase and copper in Al₂O₃/Cu composites is a key and difficult problem to achieve excellent electrical and mechanical properties of materials.With the increasing maturity of 3D printing technology in recent years,it is possible to achieve precise control of the ceramic body through 3D printing technology,thereby achieving fine control of the three-dimensional network structure Al₂O₃/Cu composite materials.In this study,3D printing technology was combined with traditional ceramic preparation process casting to prepare a structure-controlled Al₂O₃ceramic frame,and then a metal Ti coating was prepared on the Al₂O₃ frame by molten salt method to improve interfacial wettability.The three-dimensional network structure Al₂O₃/Cu composites were prepared by pressure infiltration technique.The microstructure,composition,electrical properties,mechanical properties and friction and wear properties of the composites were analyzed,which laid a solid technical foundation for the development of high-performance electrical contact materials.The research results are as follows:?1?This experiment combines FDM technology and casting molding technology to successfully prepare Al₂O₃ ceramic bodies with different frame structures.The structure of ceramic bodies can be controlled by designing PLA template structure.?2?Al₂O₃/Cu composites with different frame structure distribution can be prepared by pressureless infiltration method.Due to the molten salt method,a dense and uniform metal Ti coating is prepared on the surface of the Al₂O₃ frame,so that the interface of the Al₂O₃/Cu composite after pressureless infiltration is tightly combined.?3?The study of electrical properties of composites shows that the distribution of ceramics is more concentrated when the volume fraction of ceramics is equal,the lower the electrical resistivity of composites,the better the electrical conductivity;the more dispersed the distribution of Al₂O₃ ceramics,the resistance of composites The higher the rate,the worse the conductivity.?4?The compressive strength of the composites shows that the compressive strength of the composite is affected by two factors,namely the degree of dispersion of the ceramic body and the strength of the ceramic frame.The more dispersed the Al₂O₃ ceramic frame,the higher the compressive strength of the composite;the higher the strength of the Al₂O₃ frame,the higher the compressive strength of the composite.?4?The friction and wear properties of the composites show that the addition of the Al₂O₃ framework improves the wear resistance of the composites.The copper in the composite matrix undergoes abrasive wear and adhesive wear.When the copper on the surface is worn,the Al₂O₃ ceramic is higher than Cu at the interface to form a step,thereby protecting the copper.The more dispersed the Al₂O₃ ceramic frame,the better the wear performance of the composite material.Exposed Al₂O₃ ceramics undergo brittle fracture and spalling after prolonged wear.The higher the strength of the Al₂O₃ ceramic frame,the better the wear resistance of the composite.