Microstructures of Fe-C system Hard Alloys Produced from Mechanically Alloyed Powders.

• Kimura Yuuji

  Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University

• Takaki Setsuo

  Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University

• Goto Hideto

  Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University

Bibliographic Information

Other Title

• メカニカルアロイング粉末から作製したＦｅ‐Ｃ系硬質合金の組織
• メカニカル アロイング フンマツ カラ サクセイシタ Fe Cケイ コウシツ

Abstract

Fe-C system hard alloys were produced from mechanically alloyed powders and their properties were examined by means of hardness testing and microstructural examinations. Mixtures of iron and graphite powders (Fe-2-6mass%C) were mechanically alloyed with vibration-ball-mill in Ar atmosphere. MA powders obtained were packed in stainless steel tubes and then sealed in vacuum after degassing at 873K. The stainless steel tubes were hot-rolled in the temperature range of 923K-1273K to consolidate MA powders. Bulk materials were subjected to isothermal annealing at 1273K, followed by water quenching. After the ball-milling of 360ks, extremely large deformation energy was stored within powder particles. This leads to the formation of ultra-fine α-Fe grain and very fine dispersion of graphite. On heating to a consolidation temperature, the reaction forming Fe₃C takes place at around 600K. MA powders were completely densified to full density by hot-rolling at 1123K where the structure is of (Fe₃C+γFe) two-phase, and this consolidation process does not accompany significiant coarsening of the microstructure. In a case of an Fe-6mass%C MA bulk material, the structure at room temperature is composed of 80vol% Fe₃C and 20vol%α-Fe, so that hardness of a bulk material reaches to Hv900. But, Fe₃C is not so stable at elavated temperatures that it easily decomposes to Fe and graphite after long annealing.

Journal

• Journal of the Japan Society of Powder and Powder Metallurgy

  Journal of the Japan Society of Powder and Powder Metallurgy 43 (5), 584-589, 1996

  Japan Society of Powder and Powder Metallurgy

Keywords

• iron-carbon system
• powder
• mechanical alloying
• hard alloy

Details

• CRID: 1390282681284218112
• NII Article ID: 10002012124
• NII Book ID: AN00222724
• DOI: 10.2497/jjspm.43.584
• ISSN: 18809014
• ISSN: 05328799
• NDL BIB ID: 3967165
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I3967165
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed