Warm compaction process of P/M Steels by orthogonal testing method

Abstract

In order to achieve higher density of P/M steels using the die wall lubrication compacting method or powder lubricant in warm compaction process, the influence of different process parameters on the green density of warm compacted samples was studied. According to the orthogonal test method, the authors systematically study the influence of the different compaction pressure, condition of lubrication and compaction temperature on the green density of the sample in the warm compaction process, and put forward the optimal process parameter of warm compaction experiment. It is found that, a high compaction pressure (≥700 MPa), die wall lubrication combined with a small amount of internal lubricants, and fitting compaction temperature by different condition of lubrication, are the optimal parameters in warm compaction process.

Keywords

warm compaction / orthogonal test method / die wall lubrication / particle rearrangement / plastic deformation

References

[1] Huang P. Y. The Principle of Powder Metallurgy (2rd)[M], 2004. Beijing: Metallurgical Industry Press.

[2] Rutz H. G., Hanejko F. G. High Density Processing of High Performance Ferrous Materials[C]. Advances in Powder Metallurgy and Particulate Materials, 1994. Princeton, USA: MPIF. 117

[3] Hanejko F. Warm Compaction, ASM Handbook. Vol. 7[M], 1998. USA: ASM International Materials Park. 376-381.

[4] Hiroyuki Endo. Technology Trends in Sintered Structural Parts[J]. Hitachi Powdered Metals Technical Report, 2002, (1):3–8

[5] Lemieux P., Thomas Y., Mongenon P. E., . Combining Electrostatic Die Wall Lubrication and Warm Compaction to Enhance Green and Sintered Properties of P/M Components[C]. Proceedings of 2002 World Congress on Powder Metallurgy & Particulate Materials, 2002, 3: 34-46.

[6] Kondoh M., Okajima H. High Density Powder Compaction Using Die Wall Lubrication[C]. Proceedings of 2002 World Congress on Powder Metallurgy & Particulate Materials, 2002, 3: 47-54.

[7] K Ueda, T Machida, M Iwakiri, et al. Effect of Powder Lubricants and Compacting Temperature on the Higher Density of Iron-based Green Compacts[J]. Hitachi Powdered Metals Technical Reports, 2002, (1):24–31

[8] Capus J. M. Replacing Internal with External Lubricants[J]. Metal Powder Report, 1995, 50(7/8): 22

[9] Bocchini G. F. Warm Compaction of Metal Powders: Why It Works, Why It Requires a Sophisticated Engineering Approach[J]. Powder Metallurgy, 1999, 42(2): 171-180.

[10] Jiang G., Daehn G. S., Lannutti J. J., . Effects of Lubrication and Aspect Ratio on the Consolidation of Metal Matrix Composites under Cyclic Pressure[J]. Acta Materialia, 2001, 49: 1 471-1 477.

[11] Y Y Li, T L Ngai, D T Zhang, et al. Effect of Die Wall Lubrication on Warm Compaction Powder Metallurgy[J]. Journal of Materials Processing Technology, 2002, (129): 354–358

[12] Lemieux P., Pelletier S., Mongeon P. E., . A New Approach to Die Wall Lubrication for P/M Applications[C]. Advances in Powder Metallurgy & Particulate Materials, 2001, 3: 1-13.

[13] Li Y. Y., Li J. H., Ngai T. L., . Effect of the Admixed Lubricant Content on Die Wall Lubrication in Warm Compaction[J]. Powder Metallurgy Technology, 2004, 22(6): 341-344.

[14] Metals Handbook. Properties and Selection: Irons, Steel and High Performance Alloys[M], 1990 10th edition Materials Park, OH: ASM International. 627