Master sintering curve of binary mutually immiscible molybdenum-copper powders

In this work, the densification behavior (including shrinkage response and density fluctuation) and the dominant diffusion mechanism of binary mutually immiscible Molybdenum-Copper (Mo-Cu) composite powders are studied by a master sintering curve (MSC) strategy. Mo-Cu powders with an average particle size of 191.6 nm are sintered at temperatures up to 1300 degrees C with constant heating rates. The apparent densification activation energy is determined by mean residual square (MRS) method. The obtained value for apparent activation energy and the microstructures variation of sintered Mo-Cu indicate that surface diffusion is a dominant densification mechanism during the initial stage of sintering, while volume and (or) grain boundary diffusion dominate(s) at higher-temperature sintering stage. The MSC is constructed and subsequently validated by non-isothermal sintering experiments. Results demonstrate that the MSC is a promising strategy in estimating the densification and microstructure evolution behavior during sintering of Mo-Cu composites and could be conducive to design sintering process reasonably for Mo-Cu composites or other binary powders system. (C) 2020 Elsevier B.V. All rights reserved.