Fabrication And Properties Of ZnWO₄-coated Aluminum Borate Whisker Reinforced Aluminum Matrix Composite

With the development of science and technology and space industry, thematerials with good single property can not meet the demands, and thestructural-functional integral materials with excellent comprehensive propertieshave been more important. ZnWO₄was coated onto surface of aluminum boratewhisker by titration of chemical precipitation method. Aluminum borate whiskerreinforced aluminum matrix composite was fabricated by squeeze casting technique,and the volume fraction of reinforcement was25%， the matrix was pure-Al alloy.The microstructure of the ZnWO₄coated aluminum borate whisker and compositeswas studied by OM, SEM, TEM, XRD and DSC-TG and so on. The mechanicalproperties of composites were investigated by tensile testing and hardness testing.The radiation shielding high energy photon property of composites was calculated.The hot compression testing of composites was studied. The effect of hotcompression behaviour at different temperature and different strain rate wasdiscussed.The results of DSC-TG, XRD analysis of coated whiskers and TEMobservation of composite indicated that ZnWO₄coating did not react with thepure-Al matrix and aluminum borate whisker during the fabrication process. Thesurface roughness of whisker is increased by ZnWO₄coating, which can enhance theload transfer ability of whisker. The mechanical properties at room temperature ofcomposites are increased with the content of ZnWO₄, but decreases when theyexceed a certain degree. The result of tensile strength indicates that the ultimatetensile strength （UTS） of the composite is highest when the content of ZnWO₄is onefifth of the content of aluminum borate whisker. The introduction of ZnWO₄coatingincreased the radiation shielding property. Especially, it is more effective to shieldX-ray than to shield γ-ray. The radiation shielding property of the compositeincreased with the increase of ZnWO₄content.The hot compression test of composites showed that the flow stress ofcomposites decreased with the increase of deformation temperature or the decreaseof strain rate. In the same deformation temperature and strain rate, The flow stressof composites with higher content are larger than that of lower content. The constitutive equation for deformation was deduced.Above all, we can conclude that ZnWO₄coating can enhance the compositemechanical property and the radiation shielding property.