Production of nano-sized grains in powder metallurgy processed pure aluminum by equal channel angular densification (ECAD) and equal channel angular pressing (ECAP)


Ipekci M. T. , Gural A., TEKELİ S.

MATERIALS TESTING, vol.57, no.6, pp.580-584, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 57 Issue: 6
  • Publication Date: 2015
  • Doi Number: 10.3139/120.110749
  • Journal Name: MATERIALS TESTING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.580-584
  • Keywords: Structured sheet metal, thin sheet metal, analysis of the frequency, state of plane stress, cyclic hardening/softening behavior, SEVERE PLASTIC-DEFORMATION, NANOSTRUCTURED MATERIALS, MECHANICAL-PROPERTIES, PARTICLES, CONSOLIDATION, ULTRAFINE, ALLOY, BEHAVIOR, MICROSTRUCTURE, REFINEMENT
  • Gazi University Affiliated: Yes

Abstract

In this study, pure aluminum powders were turned into bulk material using equal channel angular densification (ECAD)/equal channel angular pressing (ECAP) and further deformed up to 16 passes at 100 degrees C. For comparison, pure aluminum powders were also compacted in a mold without ECAD/ECAP process at the same temperature. The microstructures were characterized using TEM for grain size and shape measurements. In general, the grains were finer in the specimens processed by ECAD/ECAP than in the compacted specimen without ECAD/ECAP process. The high density which is very close to the full density of pure aluminum (2.7 g x cm(-3)) was reached at the second pass of ECAD/ECAP. By the application of ECAD/ECAP process, severe plastic deformation enabled particles to be compacted into fully dense materials at much lower temperatures and shorter times, compared to the conventional sintering process. The ECAD/ECAP process was shown to provide an effective method for producing nano-sized grain and nearly full densification in aluminum powder.