| Three-dimensional continuous network Al2O3/Cu composites is a new type of copper-based materials in recent years developing,based on its good overall performance and widely range of applications,therefore received the highly concern of the domestic and foreign researchers.The main reasons:compared with traditional ceramic particles,fibers and whiskers reinforce manner Al2O3/Cu composite,Its network structure and characteristics of the constituent phases of Al2O3/Cu composite can be retained,reinforcement and toughening phase has isotropic can exert there respective advantages of alumina ceramic phase and the metallic phase,such as:copper excellent conductivity,thermal conductivity,and wear-resistant of ceramic materials and high chemical stability.But they has difference in properties between the two materials wettability,in this paper,by CVD process on foam ceramic surface metallization as to improve wettability of ceramics and metals.This paper impregnated organic foam preparation with different volume fractions of alumina foam ceramic(10pp-20ppi),Ti and I2 power as reaction raw materials.Preparation Ti Coating on foam ceramic surface by chemical vapor deposition. Finally,preparation three-dimensional network dual continuous phase Al2O3/Cu composites by vacuum EPC process.Research about infiltration temperature influence on interface binding status;The influence of ceramic volume fraction and porosity on Composite flexural strength and electrical conductivity;Friction and wear properties of composites preliminary exploration;Combined with fracture morphology and micro-structure,Discussion fracture mechanism and the wear mechanism of the Al2O3/Cu composite.The results are showed as follows:(1) The chemical vapor deposition apparatus of the present group findings had been part of the improvement can effectively improve the uniformity of the problem about titanium coating of the bulky ceramic foam core,So that to obtain a uniform coating on surface of the ceramic body and internal skeleton.Coating thickness is about 20~40um;(2) Preparing Al2O3/Cu composite by vacuum EPC impregnation,At the interface of the composite can form a distinct boundary layers as the formation of Al2O3/Ti/Custructure;With the infiltration temperature increasing, internal and interface defect of composite is reduction,binding inseparable between Al2O3 and Cu;(3) Mechanical and metallurgical bond between the Ti coating of the Al2O3 surface and Cu Forming a reactive interface,improved wettability between Al2O3 and Cu,interface products mainly Cu and Ti compound,including CuTi2 and CuTi et al.intermetallic compound,and TiO2 present on the interface of composite;(4) Three-dimensional network Al2O3/Cu composites,with increasing volume fraction of ceramic reinforced the relative density of the composite decreases,the bending strength increases,up to 178 MPa.With increasing porosity,the bending strength of the composite material is relatively lower;(5) With the increasing of the volume fraction of the composite,the resistivity of the composite increases,the relative conductivity rate fell to 60% IACS of Cu;(6) When the composite bending break,crack initiation in the ceramic particles pull and holes position.Extended to the two-phase interface along the direction of the force,ceramic phase occurs brittle fracture,Cu occurs ductile fracture,coupled with the presence of a copper titanium brittle phase at interface.weaken the binding of interface,leading to separation between coating and matrix,materials eventually destroy.(7) Friction and wear test results showed that the high-strength Al2O3 ceramic has played an effective protection on Cu matrix at friction and wear process of composite,with increasing of volume fraction of Al2O3,the effective bearing area of the composite is increased,so,the wearing rate decreased,relative wear resistance had increased;... |
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