Properties And Microstructures Research Of In-situ Al-Er-Zr-B Aluminium Alloy

Electric power is the significant indispensable energy of contemporary national development.With the development of the national economy and living standards,increasing the conductivity and heat resistance of the aluminum wire is worthy of deep study.Through the literature research,it can be found that the normal way of improving the property of aluminum wire is focused on using solid solution and aging precipitate of Fe、Cu、Zr and Er elements to enhance the heat resistance and strength of the material.However,due to the aging phase cannot pinning grain boundary and hinder the growth of grain at high temperatures,the use of such methods is limited by the thermal stability relatively poor.Therefore,our research team decided to product in situ composite which contain ZrB₂ particles,and by changing the content radio of Zr and B to research the appearance 、 formation principle and the effect of material properties by possible formation of Al3 Zr,ZrB₂,ErB₂,AlB₂/AlB12 phase.From the view of thermodynamic analysis,it can be found that the first formation phases in the system is ZrB₂.However,by the result of the deep corrosion samples from XRD analysis,Al3 Zr is the most produced phase.So we speculate that the adding order of the intermediate alloy in melting aluminum may change the order of the possible phases.By the studying the microstructure of the composites,it is found that Al3 Er is uniformly distributed in the matrix with typical eutectic structure,so it can enhance the properties of composites.the morphologies of Al3 Zr phase include thinflake、thick-plate with the two-dimensional nucleation mechanism;Part of Al3 Zr phase show nested structure is because of the phases is produced by peritectic reaction under unbalanced solidification.Throug the study of the properties,it was found that the strength of samples was enhanced with the increased of the content of Zr and B elements;After 210℃ × 4h aging treatment,the hindrance of aging precipitates reached the maximum.The enlogation of the materials is decreased with the trace elements content increased.the electrical conductivity of material decreaesed as the increased of Zr,and after aging treatment,the electrical conductivity increased because of the scattering which from solid solution reduced,in the experimental range,the change of composition had little effect of conductivity properties.After aging at 210℃×8h,the strength retention rate of all the samples was better than aging 4h.