Hot Powder Vehicle Compaction of an Atomized Stainless Steel Powder

Research Project

Project/Area Number	62550496
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	金属加工(含鋳造)
Research Institution	TOHOKU UNIVERSITY
Principal Investigator	WATANABE Ryuzo Professor, Faculty of Eng., Tohoku University, 工学部, 教授 (20005341)
Project Period (FY)	1987 – 1988
Project Status	Completed (Fiscal Year 1988)
Budget Amount *help	¥1,800,000 (Direct Cost: ¥1,800,000) Fiscal Year 1988: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1987: ¥1,500,000 (Direct Cost: ¥1,500,000)
Keywords	Hot powder vehicle compaction / Full-densification / Stainless steel powder / 完全緻密化 / 塑性流動 / 超微細組織 / 擬HIP法 / ステンレス鋼粉 / 等方圧付加熱間成形 / ステンレス綱粉 / 高速度綱粉 / 結晶粒成長抑制効果
Research Abstract	Densification and microstructural development of stainless steel powder during hot powder vehicle compaction was investigated. The preheated powder preform, vacuum encapsuled in a borosilicate glass, was compacted in a steel die using preheatedalumina granules as a pressure transmitting medium. The condition for the full-densification was determined as a function of pressure and temperature. The increase in pressure was more effective than in temperature. Three microstructural features were odserved during the compacting process; Solutioning of dendritic structure, recrystallization and normal grain growth, which in turn was found to be mainly dependent of preheating temperature. It has been found that a submicron-sized microstructure is formed during the recrystallization stage. the densification mechanism of the present compaction process has been discussed on a concept of pressure sintering map.