Influence of plasma on the densification mechanism of SPS under multi-field effect

Abstract

The densification mechanism of an Fe-based alloy powder containing tiny oxide particles under the synergic multi-field effect of spark plasma sintering (SPS) was investigated. Metallographic microscopy and scanning electron microscopy were used to observe the morphology of samples sintered at different temperatures, and the temperature distribution in an individual spherical powder particle during sintering was calculated in consideration of the influence of plasma, which was qualified and quantified through the analysis of the U-I curve. The plasma was observed to play a substantial role in activating and heating the samples at the very early stage of sintering, whereas the joule-heat effect played a dominant role during sintering. Moreover, the plasma also facilitated the diffusion and migration of materials for neck formation.

Keywords

iron alloys / spark plasma sintering / plasma / temperature distribution / densification / diffusion

References

[1] Tokita M. Chapter 11.2.3. Spark plasma sintering (SPS) method, systems, and applications. Handbook of Advanced Ceramics, 2013 2nd Ed. Oxford, Academic Press, 1149.

[2] Chang YH, Jia CC. Fe-Fe₃Al materials prepared by mechanical alloying and spark plasma sintering. Mater. Sci. Techol., 2012, 20(2): 90

[3] Meng J, Jia CC, He Q. Fabrication of oxide reinforced Ni₃Al composites by mechanical alloying and spark plasma sintering. Mater. Sci. Eng. A, 2006, 434(1–2): 246.

[4] Rajan K, Sarma VS, Kutty TRG, Murty BS. Hot hardness behaviour of ultrafine grained ferritic oxide dispersion strengthened alloys prepared by mechanical alloying and spark plasma sintering. Mater. Sci. Eng. A, 2012, 558, 492.

[5] Heintze C, Hernández-Mayoral M, Ulbricht A, Bergner F, Shariq A, Weissgärber T, Frielinghaus H. Nanoscale characterization of ODS Fe-9%Cr model alloys compacted by spark plasma sintering. J. Nucl. Mater., 2012, 428(1–3): 139.

[6] He Q, Jia CC, Meng J. Influence of iron powder particle size on the microstructure and properties of Fe₃Al intermetallics prepared by mechanical alloying and spark plasma sintering. Mater. Sci. Eng. A, 2006, 428(1–2): 314.

[7] Song XY, Liu XM, Zhang JX. Neck formation and self-adjusting mechanism of neck growth of conducting powders in spark plasma sintering. J. Am. Ceram. Soc., 2006, 89(2): 494.

[8] Liu XM, Song XY, Zhao SX, Zhang JX. Spark plasma sintering densification mechanism for cemented carbides with different WC particle sizes. J. Am. Ceram. Soc., 2010, 93(10): 3153.

[9] Olevsky EA, Froyen L. Impact of thermal diffusion on densification during SPS. J. Am. Ceram. Soc., 2009, 92, S122.

[10] Olevsky EA, Cardona CG, Bradbury WL, Haines CD, Martin DG, Kapoor D. Fundamental aspects of spark plasma sintering: II. Finite element analysis of scalability. J. Am. Ceram. Soc., 2012, 95(8): 2414.

[11] Zhao SX, Song XY, Zhang JX, Liu XM. Effects of scale combination and contact condition of raw powders on SPS sintered near-nanocrystalline WC-Co alloy. Mater. Sci. Eng. A, 2008, 473(1–2): 323.

[12] Liu XM, Song XY, Zhang JX, Zhao SX. Temperature distribution and neck formation of WC-Co combined particles during spark plasma sintering. Mater. Sci. Eng. A, 2008, 488(1–2): 1.

[13] Zhang JX, Zhao SX, Zhang GZ, Song XY. Binder-free WC bulk synthesized by spark plasma sintering. J. Alloys Compd., 2009, 479(1–2): 427.

[14] Nie JH, Jia CC, Jia X, Li Y, Zhang YF, Liang XB. Fabrication and thermal conductivity of copper matrix composites reinforced by tungsten-coated carbon nanotubes. Int. J. Miner. Metall. Mater., 2012, 19(5): 446.

[15] Lu X, Zhao LH, Zhu LP, Zhang B, Qu XH. High-temperature mechanical properties and deformation behavior of high Nb containing TiAl alloys fabricated by spark plasma sintering. Int. J. Miner. Metall. Mater., 2012, 19(4): 354.

[16] Nie JH, Jia CC, Shi N, Zhang YF, Li Y, Jia X. Aluminum matrix composites reinforced by molybdenum-coated carbon nanotubes. Int. J. Miner. Metall. Mater., 2011, 18(6): 695.

[17] Chu K, Jia CC, Liang XB, Chen H. Effect of sintering temperature on the microstructure and thermal conductivity of Al/diamond composites prepared by spark plasma sintering. Int. J. Miner. Metall. Mater., 2010, 17(2): 234.

[18] J. Appl. Phys., 2013, 113(21)

[19] Guo LN, Jia CC, Hu BF, Li HY. Microstructure and mechanical properties of an oxide dispersion strengthened ferritic steel by a new fabrication route. Mater. Sci. Eng. A, 2010, 527(20): 5220.

[20] Chang YH, Huang D, Jia CC, Ge CC, Liang D, Gao P. Oxide dispersion strengthened ferritic steel fabricated by mechanical alloying and spark plasma sintering. Powder Metall., 2014, 57(2): 103.