Studies on Compacting of Spherical Cast Iron Powders

The purpose of this study is to examine a new powder compacting method which will be described later and to investigate the properties of the compact produced. The process is as follows. A mixture of the spherical cast iron powders of about 0.2 mm in diameter and water glass is poured into a plaster mold, compacted under a low pressure, solidified by carbon dioxide gas and sintered. Then the pores of the sintered product are filled with liquid copper. The results are as follows. The sintered products containing water glass 2% compacted under 50kg/mm2 sintered for 3 hours at 1, 250°C, indicate a shrinkage of 1.6% in the direction of compaction after sintering, a porosity of 40% and a compressive strength of 2.0kg/mm2. The specimens made by injecting copper into 75% of all the pores of the above sintered product for 3 hours at 1, 150°C indicate a dimensional change of 0%, a porosity of 2%, a tensile strength of 20kg/mm2 and a compressive strength of 72kg/mm2 with 40% elongation.