Metallurgical and Thermal Properties of 57Ni-40Ti-3Hf (wt%)

Malcolm K Stanford

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NASA NTRS · 20260005881

Metallurgical and Thermal Properties of 57Ni-40Ti-3Hf (wt%)

Malcolm K Stanford

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Abstract

Selected properties of 57Ni-40Ti-3Hf (wt%) were measured to further develop this material for use in aerospace rolling-element bearings. The average grain size and microindentation hardness of the material at room temperature were 90 μm and 549 HV, respectively. From room temperature to 500 °C, electrical resistivity increased from 8.9×10–7 to 11.3×10–7 Ω⋅m, thermal expansion coefficients varied from 1.1×10–5 to 1.2×10–5 mm/mm⋅°C, specific heat increased from 0.44 to 0.53 W⋅sec/g⋅K, thermal diffusivity rose from approximately 0.003 to 0.005 cm2/sec and thermal conductivity increased from approximately 0.09 to 0.19 W/cm⋅K. The behavior of the material can be explained by well-known metallurgical theory. These results are expected to provide a basis for design and modeling of future aerospace components.

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rule of mixtures thermal conductivity thermal diffusivity specific heat thermal expansion coefficient resistivity microindentation hardness grain size intermetallics

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Malcolm K Stanford. 2025-09-01. Metallurgical and Thermal Properties of 57Ni-40Ti-3Hf (wt%). https://ntrs.nasa.gov/citations/20260005881

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