Solubility effects on grain growth and thermal conductivity of liquid-phase-sintered Mo-Cu

摘要

The low solubility of Mo in Cu hinders densification of liquid-phase-sintered Mo-Cu composites but is sufficient to enhance Mo grain growth. The effects of time and temperature on the grain growth of Mo-Cu during liquid-phase sintering are compared to those during solid-state sintering of Mo to evaluate the contributions of different mass transport mechanisms. To further compare the roles of coalescence and Oswald ripening, grain growth in Mo-Cu is compared to that of a W-Cu-Ni composition with similar solubility of the base metal in the liquid phase. At the temperatures required for liquid-phase sintering to near full density, the solubility of Mo in Cu is potentially high enough to be detrimental to the thermal conductivity. The predicted effects of Mo solubility and grain size on the thermal conductivity for different impurity sensitivities and thermal boundary conductances are compared to experimental data.