Inherent Internal Friction of Ti₅₁Ni₃₉Cu₁₀ Shape Memory Alloy

Abstract

Ti₅₁Ni₃₉Cu₁₀ SMA is more suitable than Ti₅₀Ni₅₀ SMA for use as a high damping alloy at room temperature because it has higher inherent internal friction and wider martensitic transformation temperature range. Experimental results show that tanδ values of both (IF_PT+IF_I)^B2→B19 and (IF_PT+IF_I)^B19→B19′ of Ti₅₁Ni₃₉Cu₁₀ SMA are linearly proportional to σ₀⁄ν^1⁄2 when the applied ν and σ₀ are within 10 Hz and 15 μm, respectively. Since defects and dislocations pin the martensite twin boundaries and obstruct their mobility, it is important to prevent the introduction of defects or dislocations into the solution-treated Ti₅₁Ni₃₉Cu₁₀ SMA to maintain its high inherent internal friction.