On the role of boron on improving ductility in a new polycrystalline superalloy

Paraskevas Kontis, Enrique Alabort, Daniel Barba, David M. Collins, Angus J. Wilkinson, Roger C. Reed*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

47 Citations (Scopus)


The role of boron in promoting ductility at high temperature in a prototype nickel-based superalloy designed for industrial gas turbines is studied. Both a boron-containing and boron-free variant are tested in tension at 750 °C, with further in-situ tests carried out using scanning electron microscopy (SEM), to clarify the mechanism of ductility improvement. The improvement in ductility is observed to be greater at the lowest investigated strain rate, where the grain boundary character plays a significant role on the mechanical properties; no ductility improvement was observed at the highest investigated strain rate. The in-situ tests were also performed at 750 °C and revealed directly the greater susceptibility of the grain boundary morphology in the boron-free case to fracture and – in the boron-containing case – the mechanism of ductility enhancement. The findings are supported further by high-resolution electron backscattered diffraction (HR-EBSD) strain mapping which confirms that the distribution of elastic strain and geometrically necessary dislocation (GND) content are influenced markedly by boron addition. The mechanism through which boron indirectly enhances the mechanical properties at elevated temperatures is discussed.

Original languageEnglish
Pages (from-to)489-500
Number of pages12
JournalActa Materialia
Early online date22 Nov 2016
Publication statusPublished - 1 Feb 2017


  • Grain boundaries
  • In-situ
  • Nickel-based superalloys
  • Strain mapping

ASJC Scopus subject areas

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


Dive into the research topics of 'On the role of boron on improving ductility in a new polycrystalline superalloy'. Together they form a unique fingerprint.

Cite this