Microstructure, Mechanical and Shielding Properties of Fe67.5Ni23.5B9 Coating / 321 Stainless Steel Laminated Composite by the Air-plasma Spraying Procedure

To meet the requirements of integrative mechanical properties and shielding effectiveness of nuclear radiations shielding materials, the boron-rich shielding coating (Fe67.5Ni23.5B9, in wt. %) were produced onto 321 stainless steel substrate (SS) by the air-plasma spraying technology. This type of coating-SS laminated composite will be likely to be used as protection against neutrons and gamma rays from radiation shielding systems. The microstructure was characterized by scanning electron microscope (SEM), energy-dispersive spectrometry (EDS) and X-rays diffraction (XRD). The mechanical properties of Fe67.5Ni23.5B9 coatings were investigated, including adhesion strength, tensile properties and residual stress. The shielding effectiveness of the coating-SS laminated composite, including the slowing down of fast-speed neutrons, absorption for 0.4ev below thermal neutrons and the attenuation against 60Co and 137Cs gamma rays were investigated. The results show that the produced Fe67.5Ni23.5B9 coatings-SS laminated composite possess homogeneous microstructure, satisfactory integrative mechanical properties and shielding effectiveness which testify the possible application in radiation shielding systems.