Bulk ultrafine-grained Nickel consolidated from nanopowders

J. Gubicza, H. Q. Bui, F. Fellah, N. Szász, G. Dirras

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Ultrafine-grained samples were consolidated from Ni nanopowders with the nominal particle size of 50 and 100 nm by Hot Isostatic Pressing (HIP) and Spark Plasma Sintering (SPS). The higher nickel-oxide content and the smaller grain size of SPS-processed samples result in a higher yield strength at room temperature compared with HIP-processed specimen. It is found that during compression the dislocation density increases while the twins decay in both samples, indicating that the deformation is mediated mainly by dislocations. As a consequence of the higher oxide content, the flow stress of the SPS-processed samples saturates at small strain values while the HIP-processed specimen shows strain hardening even at the strain value of 0.35. After saturation of the flow stress for SPS-processed samples the deformation is most probably mediated rather by grain rotation or grain boundary-related mechanisms such as sliding and/or decohesion instead of dislocation motion.

Original languageEnglish
Pages (from-to)93-98
Number of pages6
JournalMaterials Science Forum
Volume589
DOIs
Publication statusPublished - 2008

Fingerprint

Spark plasma sintering
Nickel
Hot isostatic pressing
sparks
hot isostatic pressing
nickel
sintering
Plastic flow
Nickel oxide
Strain hardening
Oxides
nickel oxides
strain hardening
Yield stress
yield strength
Grain boundaries
Compaction
Particle size
sliding
grain boundaries

Keywords

  • Hot Isostatic Pressing (HIP)
  • Mechanical properties
  • Microstructure
  • Nanopowders
  • Spark Plasma Sintering (SPS)

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

Cite this

Bulk ultrafine-grained Nickel consolidated from nanopowders. / Gubicza, J.; Bui, H. Q.; Fellah, F.; Szász, N.; Dirras, G.

In: Materials Science Forum, Vol. 589, 2008, p. 93-98.

Research output: Contribution to journalArticle

Gubicza, J. ; Bui, H. Q. ; Fellah, F. ; Szász, N. ; Dirras, G. / Bulk ultrafine-grained Nickel consolidated from nanopowders. In: Materials Science Forum. 2008 ; Vol. 589. pp. 93-98.
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