| Effects of graphite shape and pearlite ratio on thermal properties of a compacted vermicular graphite cast iron(CVGCI) were studied. Thermal expansion coefficients, thermal conductivities, specific heats and thermal diffusivities of flaky graphite cast iron(FGCI), CVGCI and spheroidal graphite cast iron(SGCI) were correctly measured. Thermal diffusivity decreases as the nodularity of graphite, temperature and the pearlite ratio in matrix increase. FGCI shows higher temperature dependency compared with CVGCI and SGCI. Linear correlation is obtained between thermal diffusivity(α) and the pearlite ratio in matrix(p) as α=α_0(1-4.3×10^(-3). p), where α_0 is thermal diffusivity of the ferrite matrix. (Received January 26, 1987) |
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