Effect of carbide powder characteristics on the PVT behavior of powder injection molding compounds

Effect of powder concentration and particle size distribution of highly filled cemented carbide compounds on their pressure-volume-temperature (PVT) characteristics and thermal properties was investigated. PVT data of compounds containing up to 50 vol.% of powder evaluated on a high-pressure mercury dilatometer reveals that the pressure influences both detected phase transitions, but it causes a different effect on the melting and crystallization of the material only for the higher transition (corresponding to binder components with melting temperatures 100 and 107 °C). The discrepancies in specific volumes at an applied pressure diminish with increasing powder content, whereas melting temperatures - derived from differential scanning calorimetry - remain unaffected. Volumetric thermal expansion coefficient and compressibility are linearly and exponentially, respectively, dependent on pressure. Further, the variance in the particle size distributions of carbide compounds resulted in shifts in both volumetric thermal expansion coefficients and compressibility values.