Study On Preparation And Properties Of Three Dimensional Network Alumina/Copper Composites

The three-dimensional network Al2O3/Cu composite is a new type of high-performance composite material.Because of its good comprehensive performance,it has been widely applied,and has attracted great attention from scholars at home and abroad.The ceramic phase and the metal phase in the three-dimensional network Al2O3/Cu composite are three-dimensional continuous structures,and the two phases cross and support each other.This unique three-dimensional structure facilitates the rapid transfer and consumption of energy(such as load,heat,etc.)on the composite material.In addition.Cu has excellent electrical and thermal conductivity,Al2O3 has good wear resistance and chemical stability,three-dimensional network Al2O3/Cu composites can play the advantages of Al2O3 and Cu.Therefore,three-dimensional network Al2O3/Cu composite has application prospects in integrated circuit lead frame,switch and electrical contact material.In this paper,Al2O3 foam ceramics with high porosity were prepared by organic foam impregnation method.The preparation process was optimized and the influence of pore structure on mechanical properties was analyzed.On this basis,three-dimensional network Al2O3/Cu was prepared by pressureless infiltration method.Composite materials,in-depth analysis of the Al2O3 and Cu interface wetting improve the method and mechanism,the preliminary discussion of the thermal conductivity and wear resistance of the composite material.The results of the study are as follows:(1)Al2O3 foam ceramics with a porosity of 60 to 90%and a high pore connectivity can be prepared by organic foam impregnation.The number of impregnations and the specification of the organic foam(PPI)have a significant effect on the porosity,pore size,and compressive strength of Al2O3 foam ceramics.(2)The oxygen content in Cu affects the interfacial wettability of Cu and Al2O3.As the oxygen content increases,the interface wetting angle gradually decreases.When the oxygen content is 12at.%,the interface wetting angle is 23.2°.The phase analysis showed that CuAl2O4 was formed by the interface reaction between Cu-CuO block complex and Al2O3 at high temperature.(3)The Al2O3/Cu composites can be prepared by pressureless infiltration at 1300? with the oxygen content of 12at.%Cu-CuO block complex as the metal melt and the Al2O3 ceramic foam as the preform.The preparation process of three-dimensional network Al2O3/Cu composites was optimized,The best process parameters were infiltration temperature 1300?,infiltration time of 2h and oxygen content of 12at.%.(4)Preliminary discussion on thermal conductivity and wear resistance of three-dimensional network Al2O3/Cu composites.With the increase of ceramic phase content,the thermal conductivity of composites gradually decreases,The change range is 179.22?266.77w/m·K,but the wear rate is reduced.The wear rate of composite material prepared by Al2O3 with 75%porosity is 0.020mm3/m·N.