Preparation Process And Microstructure Properties Of Functional Aluminum Matrix Composites With CsPbBr₃ Addition

The charge carrier of metallic halide perovskite materials can exist for a long time and has a high transmission rate,while the band gap can be adjusted flexibly to achieve high fluorescence emission.Aluminium alloy has good high temperature properties,high strength and toughness as matrix material.The combination of perovskite nanoparticles and aluminum alloy matrix materials can not only improve perovskite encapsulation effect,improve its air and thermal stability,but also obtain novel aluminum matrix composites with fluorescence function,which have potential applications in the fields of internal crack detection and surface security.In this thesis,functional 6061 aluminum matrix composites with homogeneous dispersion of CsPbBr₃ nanocrystals were synthesized directly at high temperature by in situ reaction combined with powder metallurgy.The influence of sintering process and phase content on macroforming,microstructure,phase composition,fluorescence and hardness of CsPbBr₃/6061Al composites was investigated.Emphasis was placed on comparing 10 wt under the same preparation conditions.Microstructure,phase,fluorescence,and mechanical properties of%CsPbBr₃/6061Al composite and 6061aluminum alloy revealed a composition-microstructure/property correspondence between CsPbBr₃/6061Al composite.The main conclusions are as follows:By changing the thermal pressure sintering temperature between 460℃ and 560℃,the density,microhardness and ductility of 6061 aluminum alloys increased with the increase of the thermal pressure sintering temperature,but the tensile strength first increased and then decreased,reaching the highest at 540℃ because the granules became coarse at 560℃,which resulted in a decrease in tensile strength.6061 Aluminium alloy had an optimum sintering temperature of 540℃ and sample density,mean microhardness,ductility and tensile strength were 2.71 g/cm3,44.05HV_0.05,16%and 124 MPa.CsPbBr₃/6061Al composites with mass of 5%,10%and 20%were prepared by in situ reaction and powder metallurgy,respectively.It was found that with the increase of CsPbBr₃ nanoparticles,the fluorescence intensity of the composites increased gradually,but the corresponding molding properties became worse and penetrating cracks appeared in the samples.The microhardness of CsPbBr₃/6061Al composites fluctuated significantly in the range of 50-120 HV_0.05 due to the presence of multiple phase components in the composites.The CsPbBr₃/6061Al composite with perovskite nanoparticle mass of 10%was the best composite material considering the macroforming,microcracking and fluorescence properties of the composites.By comparing the microstructure,fluorescence characteristics and mechanical properties between 10 wt.%CsPbBr₃/6061Al composite and 6061 aluminum alloy,the main microstructure groups in 10 wt.%CsPbBr₃/6061Al composite wereα-Al solid solution,Pb monolayer phase and a large number of diffusely distributed CsPbBr₃ perovskite nanocrystals with size less than 20 nm.The CsPbBr₃ perovskite nanocrystals emit green fluorescence at a wavelength of 520 nm when exposed to UV light,resulting in uniform fluorescence properties of the composites.As a comparison substrate,the microstructure of 6061 aluminum alloys prepared by powder metallurgy,includingα-Al solid solutes,Si monolithic phase,and Fe-richβ-phase withπphase,had no fluorescence properties and showed a microhardness of approximately 50HV_0.05 compared to 10 wt.%CsPbBr₃/6061Al composites,the overall hardness of the composites was approximately 1.5 times higher than that of 6061 aluminum alloys due to the presence of Pb monomer and CsPbBr₃ nanocrystals.