Effect of Polyethylene Glycol (PEG) Powder on Compressibility and Microstructural Properties of Sintered alpha-Alumina

This study examines the effect of various contents of polyethylene glycol (PEG) powders on density, compressibility, and microstructural properties of sintered alpha-alumina samples. Moreover, the effect of compaction pressure on the green density of the compacts is studied by applying different pressures ranging from 400 to 550 MPa. Samples were prepared by mechanical blending of alumina and various amounts of PEG powders in a Turbula mixer. The binder contents vary from 1 wt.% to 4 wt.%. The as-prepared mixture was compacted in a universal machine at room temperature under the pressure of 6MPa to produce disk-shaped samples in a pre-compaction step. Experimental results revealed that adding various amounts of PEG powders has a detrimental effect on the green density of alumina pellets and decreases the green density from 1.95 to 1.87 g/cm(3). The results also show that sintered density of samples increased by increasing the compaction pressure to pressures higher than 400 MPa. It is observed that a sudden increase in green density has been observed between 450 and 550 MPa.