Evaluation of Low-Damping Properties Induced by Plastic Deformation and Heat Treatment in Co-Ni-Cr-Mo-Based Alloy

Abstract:

The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt% Nb addition after various plastic deformation and heat treatment processes were investigated. Through Vickers hardness tests, free resonance Young's modulus measurements, and microstructure analysis, the effects of dislocation density, vacancy formation, and recrystallization on the alloy performance were clarified. Results indicate that increasing the rolling reduction enhances damping property due to higher dislocation density, whereas aging below the recrystallization temperature reduces damping property via dislocation pinning by the Suzuki effect. Recrystallization heat treatment restores the original structure and damping level. This alloy possesses tensile strength of approximately 1500 MPa and logarithmic decrement value δ^-1 in the range of 2×10^-4–3×10^-4, demonstrating superior mechanical properties compared with the Ti-based alloys, which makes it an excellent candidate material for ultrasonic tools and medical applications.