Structural Characterization, Bonding Performance, and Residual Stress Analysis of Titanium alloy/Cemented Carbide Composite Tubes with V/Fe Composite intermediate layers

Abstract

The fabrication of titanium alloy/cemented carbide composite tubes significantly improves the wear resistance of the titanium alloy, demonstrating promising application potential in aviation, transportation, and defense industries. However, the formation of brittle intermetallic compounds between titanium alloy and cemented carbide, coupled with their significant thermal expansion coefficient differences, poses challenges to enhancing interface bonding performance. In this work, the interface microstructure and interfacial bonding performance of titanium alloy/cemented carbide composite tube with interlayer of V and Fe foils were studied. In addition, experimental characterization based on digital image correlation (DIC) and numerical simulation were carried out to investigate the residual stress in the composite tubes. Results indicate that local shear strength decreases from top to bottom, with a maximum value of 294.5 MPa, while annular shear strength remains relatively uniform along the tube length, peaking at 230.5 MPa. Shear failure occurs at the V/Fe interface due to the presence of brittle V₂C and V₆C₅ phases. The absolute value of the residual stress in the titanium alloy layer decreases radially outward. During the diffusion bonding stage (DBS), titanium alloy is subjected to solid particle medium loading, resulting in compressive principal stress dominated by S33 (σ_θ). In the cooling stage (CS), thermal contraction maintains compressive principal stress, mainly S11 (σ_R). Along the tube height during DBS, all stress components exhibit minimum absolute values in the mid-section. At CS, only S22 (σ_Z) shows the lowest magnitude in the middle region. The post-cooling compressive stress contributes to enhanced interfacial bonding strength. This study provides a theoretical basis for the fabrication and residual stress testing for titanium alloy/cemented carbide composite tube.