Research On Fabrication Technique And Property Of Cast Aluminum Alloy Reinforced By High Entropy Alloy Particles

High entropy alloy particles reinforced aluminum matrix composite with high strength,good toughness and interfacial wettability is a kind of overlight and well performed aluminum matrix composite,widely used in airspace,automotive,communication and LED industry etc.However,fabrications of high entropy alloy particles reinforced aluminum matrix composites is concentrated on solid state method.Liquid method has rarely been reported yet.In this paper,high entropy alloy particles reinforced cast aluminum alloy were fabricated by pressure infiltration.The effects of casting temperature,reinforcement volume fraction and ball milling process?dry-milling,wet-milling?on the microstructure,mechanical properties with Al_0.25Cu_0.75FeCoNi particles reinforced aluminum alloy were investigated.According to optimized parameters,AlSiTiCrNiCu particles reinforced aluminum matrix composites were fabricated.Main conclusions are as follows:Al_0.25Cu_0.75FeCoNi particles were synthesised by dry milling and wet milling.One average particle size is 53.6?m,the other is 15.7?m.Al_0.25Cu_0.75FeCoNi particles are FCC crystal structure.AlSiTiCrNiCu particles with average 10.4?m were synthesized by wet-milling.AlSiTiCrNiCu particles are BCC crystal structure.The.High entropy alloy particles reinforced aluminum alloy was fabricated by pressure infiltration.With casting temperature elevating,the average grain size and indiffusion layer thickness of dry milled-pressure infiltrated(Al_0.25Cu_0.75FeCoNi)_p/Al-Si composite increase continuously.Hardness increases gradually while tensile strength enhances first then declines,but elongation decreases.As volume fraction increases,the tensile strength of dry milled-pressure infiltrated(Al_0.25Cu_0.75FeCoNi)_p/Al-Si composite reduces gradually,but elongation deeps obviously.With increase of casting temperature,the interdiffusion layer of wet milling-pressure infiltration Al_0.25Cu_0.75FeCoNi composite increases continuously.As volume fraction decreases,the agglomerate phenomenon is gradually reduced.The tensile strength increases first then declines,while the elongation enhances gradually.When casting temperature is 720?and volume fraction is 5%,dry milled Al_0.25Cu_0.75FeCoNi particles are uniformly distributed in the matrix,but the wet milled ones tend to agglomerate.The tensile strength of dry milled-pressure infiltrated(Al_0.25Cu_0.75FeCoNi)_p/Al-Si composite is 162 MPa,and wet milled-pressure infiltrated(Al_0.25Cu_0.75FeCoNi)_p/Al-Si composite is 174 MPa,which is 5.2%and 13.0%higher than that of matrix alloy,respectively,but elongation is worse than that of matrix alloy.The later ones deep more.The interfacial bonding types of dry and wet milled-pressure infiltrated(Al_0.25Cu_0.75FeCoNi)_p/Al-Si composites are diffusion bonding interface.When casting temperature is 720?and volume fraction is 1%,reinforcement distributes uniformly in?AlSiTiCrNiCu?_p/Al-Si composite.The average layer is 650 nm,and interfacial bonding type is diffusion bonding interface.The tensile strenghth of?AlSiTiCrNiCu?_p/Al-Si composite is 185 MPa,elongation 14.6%,density 2.74 g/cm³,which is the best performance materials in this paper.