A Model for the Consolidation of Ultrafine Metal Powders

摘要

The refractory metals are fabricated from powders and often for engineered shapes this is via the press and sinter route. Such components might be used in electronic applications such as heat sinks. The properties required in the final product often create challenges in processing. A model has been formed for the press-sinter processing of ultrafine and nanoscale refractory metal powders. It predicts apparent density, green density, sintered density, sintered grain size, sintered hardness and strength. Further, the model has been extended to predict performance attributes using simple inputs of particle size, temperature, pressure, impurity level, and sintering time based on current understanding of the microstructure evolution during processing. This model has been applied to several refractory metal systems, with the emphasis here on tungsten. Sucess relies on a work of sintering concept captured in a single parameter master sintering curve. Demonstrations of property predictions show how novel press-sinter cycles can be isolated for a variety of applications. This predictive capability allows for process and product optimization based on selected performance features.