In-situ Micro-CT analysis of deformation behavior in sandwich-structured meta-stable beta Ti-35Nb alloy

Beta Ti-35Nb sandwich-structured composites with various reinforcing layers were designed and produced using additive manufacturing (AM) to achieve a balance between light weight and high strength. The impact of reinforcing layers on the compressive deformation behavior of porous composites was investigated through micro- computed tomography (Micro-CT) and finite element method (FEM) analyses. The results indicate that the addition of reinforcement layers to sandwich structures can significantly enhance the compressive yield strength and energy absorption capacity of porous metal structures; Micro-CT in-situ observation shows that the strain of the porous structure without the reinforcing layer is concentrated in the middle region, while the strain of the porous structure with the reinforcing layer is uniformly distributed; FEM analysis reveals that the reinforcing layers can alter stress distribution and reduce stress concentration, thereby promoting uniform deformation of the porous structure. The addition of reinforcing layer increases the compressive yield strength of sandwich-structured composite materials by 124% under the condition of limited reduction of porosity, and the yield strength increases from 4.6 to 10.3 MPa.