Developing suitable powder blends for ceramic dry powder pressing requires the precise manipulation of several parameters to ensure the powder fills the die effectively and forms a stable green body. Given the financial and temporal penalties incurred in running plant trials, a way of characterizing powder blends to identify those with suitable in-process behavior would both accelerate and optimize the development cycle.
Dry powder pressing under isostatic conditions, followed by sintering and machining, is one of the most flexible and cost-effective techniques for producing high-performance ceramic components. However, the quality of the finished part is dependent on the specific powder blend readily discharging from the hopper, filling the die fully, and compressing to form a stable green body that does not shrink unacceptably during sintering. Finer particles tend to form more homogeneous green parts and, ultimately, fewer defects, but often fill dies poorly even while displaying excellent flow characteristics in conventional tests.