Identification of whisker grain in Sn coatings by analyzing crystallographic micro-texture using electron back-scatter diffraction

Piyush Jagtap, Aritra Chakraborty, Philip Eisenlohr, Praveen Kumar

Research output: Contribution to journalArticle

  • 3 Citations

Abstract

Here, we attempt to understand the age-old question of “where do whiskers in Sn coatings grow?” by performing grain orientation mapping in conjunction with a simple analysis of the stress field in the vicinity of a whisker grain. Electron back-scatter diffraction (EBSD) was used for orientation mapping of Sn grains in a 4 μm thick Sn coating deposited on brass. It was observed that whiskers consistently grew from low-index grains with (100) or near-(100) orientations that were surrounded by grains with similar orientations, which were then partially surrounded by grains with high-index planes, such as (211), (321) and (420). Strong elastic anisotropy and overall a high fraction of high-angle grain boundaries were also consistently observed in the vicinity of whiskers. In addition, a full-field three-dimensional crystal elasticity simulations were performed using the EBSD orientation maps to analyze local stress variations in the vicinity of the whisker grain. These simulations indicate the presence of a high compressive hydrostatic stress around the whisker grain, which could then possibly create conducive conditions for whisker growth observed experimentally.

LanguageEnglish (US)
Pages346-359
Number of pages14
JournalActa Materialia
Volume134
DOIs
StatePublished - Aug 1 2017

Profile

Textures
Diffraction
Coatings
Electrons
Brass
Crystal orientation
Elasticity
Grain boundaries
Anisotropy
Crystals

Keywords

  • EBSD
  • Micro-texture mapping
  • Sn whisker
  • Stress field mapping
  • Whisker location

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

Cite this

Identification of whisker grain in Sn coatings by analyzing crystallographic micro-texture using electron back-scatter diffraction. / Jagtap, Piyush; Chakraborty, Aritra; Eisenlohr, Philip; Kumar, Praveen.

In: Acta Materialia, Vol. 134, 01.08.2017, p. 346-359.

Research output: Contribution to journalArticle

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