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 You...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 valueδ^(-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.展开更多
The influence of Hf on the precipitation behavior of γ'phase and the subsequent tensile properties of a Ni-Cr-Mo alloy after long-term thermal exposure was investigated.The results reveal that the addition of Hf ...The influence of Hf on the precipitation behavior of γ'phase and the subsequent tensile properties of a Ni-Cr-Mo alloy after long-term thermal exposure was investigated.The results reveal that the addition of Hf increases the average diameter ofγ'phases after thermal exposure at 700℃ for 5000 h,which enhances the critical resolved shear stress required for dislocations to shear the γ'phases in the Ni-Cr-Mo alloy.Simultaneously,element Hf incorporated into the γ'phases increases the lattice mismatch between the γ'and γ phase,thereby strengthening the coherency strengthening effect.These two factors collectively contribute to the enhanced strength of the alloy.Thus,Hf alloying effectively improves the yield strength of the Ni-Cr-Mo alloy after thermal exposure at 700℃.展开更多
文摘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 valueδ^(-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.
基金National Key Research and Development Program of China(2021YFB3704103)National Natural Science Foundation of China(51571191)。
文摘The influence of Hf on the precipitation behavior of γ'phase and the subsequent tensile properties of a Ni-Cr-Mo alloy after long-term thermal exposure was investigated.The results reveal that the addition of Hf increases the average diameter ofγ'phases after thermal exposure at 700℃ for 5000 h,which enhances the critical resolved shear stress required for dislocations to shear the γ'phases in the Ni-Cr-Mo alloy.Simultaneously,element Hf incorporated into the γ'phases increases the lattice mismatch between the γ'and γ phase,thereby strengthening the coherency strengthening effect.These two factors collectively contribute to the enhanced strength of the alloy.Thus,Hf alloying effectively improves the yield strength of the Ni-Cr-Mo alloy after thermal exposure at 700℃.
