Correlations between powder deposition methods and green compact quality: Part II compact quality and correlations

The effect of three deposition methods (funnel, rainy and feed shoe) was studied on the green compact quality of two powders - microcrystalline cellulose (MCC) and silicon nitride (KY 3500). The green compacts were prepared using a commercially available single-action mechanical press namely the Powder Testing Center (PTC)1. These compacts were then tested for their quality using a universal testing machine (Instron 1000), The various compact quality parameters that were determined included axial compressive strength, radial strength and work of failure (axial and radial). From the compact quality tests, it was observed that in 6 out ofl2 cases for KY 3500 compacts, there was a good linear correlation (R²>0.90) between compact quality parameters and isotropic pressure of compaction. In the case of MCC compacts, 10 out of 12 cases had a good linear correlation (R²>0.90) between quality parameters and isotropic pressure of compaction. In addition, for KY 3500 compacts, the deposition methods had a pronounced effect on compact quality. For MCC compacts, the deposition methods did not affect the compact quality. Statistical correlations were developed between the powders’ engineering parameters (as determined in Part I) and compact quality parameters for the three deposition methods. It was observed that some of the compact quality parameters correlated very well (R²>0.90) with some of the elastoplastic parameters.