Effect of polyacrylic acid (PAA) binder system on particle orientation during dry-pressing

Effect of polyacrylic acid (PAA) binder system on the development of particle orientation during uniaxial pressing is reported. Granules of different properties were compacted using uniaxial pressing at various pressure and their degree of particle orientation (DPO) was determined. The increment trend of DPO varies with granule strength and shows higher value for binder system of higher flexibility. Anisotropic shrinkage related to particle orientation is shown by compact of higher relative density (RD) and DPO; whereas anisotropic shrinkage related to non-uniform packing density is shown by compact of lower RD and DPO. Anisotropic shrinkage remains in the former compact while isotropic shrinkage was obtained for the latter compact at sintering temperature of 1600 °C. Subsequent cold isostatic pressing increases DPO and sintering shrinkage ratio of uniaxially pressed compacts.

The effect of polyacrylic acid (PAA) binder on the development of particle orientation during uniaxial pressing is reported. The degree of particle orientation increases with uniaxial pressure and relative density. Its development varies with granule strength and shows a higher value for the binder of higher flexibility. The compact of high degree of particle orientation and high relative density shows anisotropic shrinkage during sintering.Figure optionsDownload as PowerPoint slide