| 摘要 |
PURPOSE:To obtain a material of high density, by presintering the fine particles after they are compressed and moulded, and by crushing the pores with the second compression and moulding and sintering the fine particles again. CONSTITUTION:3% graphite powder of 1-3mum in particle diameter is added to 3% Si-Fe powder of 200 mesh in particle size. After both powders were mixed with a V-shaped mixer for four hours, they were compressed to mould under the condition of 6t/cm<2>. The mixed powder was then presintered for one hour at the temperatures of nine grades in 800-1,140 deg.C. After the rate of change in size is measured, the mixed powder was compressed and moulded under the same condition of 6t/cm<2>. The figure shows the flux density B50 and vibration damping factor for the finished product obtained by sintering the compact at 1,140 deg.C for five hours. The value of flux density B50 improves up to about 13 KG by the resintering at more than 900 deg.C. The vibration damping factor reduces, but it is at about the same degree as in Fe-Cr-Al alloy well- known as a vibration proofing material. The reduction is so trivial that it wont be much of a problem. |
