Acta Metallurgica Sinica (English Letters) ›› 2009, Vol. 22 ›› Issue (6): 447-453.DOI: 10.1016/S1006-7191(08)60122-2

• 研究论文 • 上一篇    下一篇

Green properties and stress wave of high velocity compacted iron powder

王建忠1;Qu Xuanhui2;Yin Haiqing2   

  1. 1. 北京科技大学
    2.
  • 收稿日期:2009-01-09 修回日期:2009-03-16 出版日期:2009-12-25 发布日期:2009-12-16
  • 通讯作者: 王建忠
  • 基金资助:

    国家973计划;教育部长江学者和创新团队发展计划

Analysis of density and mechanical properties of high velocity compacted iron powder

Jianzhong WANG, Haiqing YIN, Xuanhui QU   

  1. State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2009-01-09 Revised:2009-03-16 Online:2009-12-25 Published:2009-12-16
  • Contact: Xuanhui QU

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摘要：

High velocity compaction (HVC) process is a new method for producing higher density PM parts. In the paper water atomized pure iron powder with no any lubricant added was compacted by the technique. The relationships among the impact velocity, the green density, the stress wave and the bending strength were discussed. Scanning electron microscopy (SEM) and a computer controlled universal testing machine were used to study the morphologies and the bending strength of samples, respectively. The results show that with increasing impact velocity, the green density and the bending strength increase gradually. Furthermore, the maximum impact pressure increases gradually and the duration of stress wave prolongs slowly as the impact velocity rises up. The comprehensive effect between the pressure and the duration of stress wave leads to the green density increasing. In the study, the optimal impact velocity is 9.8 m/s, achieving the green density of 7.513 g/cm3 and the bending strength of 61 MPa.

关键词: powder metallurgy, high velocity compaction, green properties, stress wave, bending strength

Abstract:

A new method for producing higher density PM parts, high velocity compaction (HVC), was presented in the paper. Using water atomized pure iron powder without lubricant admixed as the staring material, ring samples were compacted by the technique. Scanning electron microscopy (SEM) and a computer controlled universal testing machine were used to investigate the morphologies and the mechanical properties of samples, respectively. The relationships among the impact velocity, the green density, the sintered density, the bending strength and the tensile strength were discussed. The results show that with increasing impact velocity, the green density and the bending strength increase gradually, so the sintered density does. In addition, the tensile strength of sintered material is improved continuously with the sintered density enhancing. In the study, the sintered density of 7.545~g/cm3 and the tensile strength of 190~MPa are achieved at the optimal impact velocity of 9.8 m/s.

Key words: Powder metallurgy, High velocity compaction, Density, Mechanical properties, Iron powder