In production of ceramic components and powder metallurgy parts, granulated powder is commonly compacted to form dense powder compacts for subsequent firing process. The compaction characteristics of granulated powder are not only important in the process design of packing and compacting, but also give us insights into previous granulation and influence properties of final fired product. We proposed a simple and practical method to evaluate compaction characteristics for powder by uniaxial pressing test, improved in measurement of both axial and lateral stresses. Assuming the associated flow law, a yield function modeled in a form relating to both the first- and the second-stress-invariant can be evaluated. Furthermore, the apparent elastic coefficients can be evaluated by the same uniaxial pressing test with an elastic behavior during unloading the pressure applied to the powder-compact specimen. This evaluation method is applied to Aｌ2O3-C based granulated powder for evaluating the yield function and elastic coefficients.

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