Study On Preparation And Performance Of Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁ Hollow Sphere Aluminum Matrix Composites

With the development of society and economy,human’s demand for energy is gradually increasing.As a new type of clean energy,nuclear energy is used more and more widely.However,the damage caused by nuclear radiation cannot be ignored.Traditional nuclear shielding materials,such as shielding concrete and polyethylene composite shielding materials,highlight the limitations of high density,poor heat resistance and corrosion resistance in the process of using.It can not meet the needs of the existing nuclear protection,so it is urgent to develop new shielding materials.The existing research shows that the metal hollow spherical aluminum matrix composite has good mechanical properties and shielding properties due to its special structure.The development of this structural material provides a new way to solve the new nuclear shielding composite.Therefore,in this paper,a new kind of metal hollow sphere is designed.Starting from the preparation process of Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁alloy powder,the preparation,microstructure and properties of hollow sphere aluminum matrix composite are analyzed,and the shielding mechanism of the composite is discussed.Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁ alloy powder was prepared by mechanical alloying process with high purity Fe powder,Ni powder,Al powder,B powder and W powder as raw materials.It The effect of ball milling time on the phase composition and particle morphology of mixed metal powder was investigated.The optimum ball milling time of Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁ alloy powder was obtained under the parameters of ball milling speed of 300r/min and ball material ratio of 10:1.Based on this,the optimum preparation technology of Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁hollow spheres was obtained by studying the effects of raw material ratio,binder concentration and coating machine speed on coating effect of Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁ hollow spherical spheres.Then,by studying the effect of sintering temperature on the physical parameters and microstructure of Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁hollow spheres,it is found that the density,diameter shrinkage and wall thickness shrinkage of hollow spheres increase with the increase of sintering temperature,and porosity decreases.After the embryo was sintered at1350℃,the porosity of the hollow spheroid was 18.78%,and body-centered cubic,face-centered cubic and close-packed hexagonal phases were precipitated in the hollow spheroid wall.Finally,the technology of Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁ hollow spheres was optimized.Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁ hollow spherical aluminum matrix composites were prepared by powder metallurgy.The effects of sintering temperature and sintering pressure on the preparation and properties of the composites were studied.The results show that the thickness of the transition layer between the hollow sphere and the matrix increases with the increase of sintering temperature under the condition of constant sintering pressure,and the shape of the transition layer changes from discontinuous type to continuous type.The transition layer is mainly composed of metal compound phase formed by Fe,Ni,W,Al atoms diffusing with each other.However,when the sintering temperature is 560℃,the sintering pressure increases,the thickness of the transition layer between the hollow sphere and the matrix increases,and the boride phase appears in the metal compound of the transition layer.The mechanical properties of the composites increase with the increase of sintering temperature and pressure.When the sintering temperature is 560℃and the sintering pressure is 8 MPa,the maximum compressive strength and platform stress of the composites are 180.35 MPa and117.05 MPa,respectively.The shielding properties of Fe₂₆Ni₂₆Al₂₆B₁₁W₁₁ hollow spherical aluminum matrix composites were studied by experimental method.The results show that the transmission coefficients ofγrays and thermal neutron rays decrease with increasing volume fraction of the hollow sphere.When the volume fraction of the hollow sphere is 60%,the gamma energy is 121.78 Ke V,and the thickness of the composite is 3.8 cm,the shielding rate of the composite is 98.71%.When the energy ofγrays is low,the effect of the volume fraction of hollow sphere on the shielding performance ofγrays is obvious.When the volume fraction of the hollow sphere is 60%and the thickness of the composite is 2.8 cm,the shielding rate of the composite is 65.90%.