Surface hardening characteristics of microalloyed steel during ex-situ and in-situ Al2O3 reinforcement under TIG arcing

Deepak Sharma, Prakriti Kumar Ghosh, Nilesh Kumar, Ramkishor Anant

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


This work presents a comparative study of the influence of producing ex-situ and in-situ surface composite (by Tungsten Inert Gas (TIG) arcing process) on the hardenability of microalloyed steel, hereafter mentioned as steel. The ex-situ surface composite was prepared by adding hard Al2O3 particles into the fused surface matrix, while for in-situ surface composite, Al2O3 particles were made to grow in the fused surface matrix through the addition of Al. In the latter process, Al as deoxidizer reacts with the oxygen present in the steel to form the in-situ growth of Al2O3. The modified surface matrix exhibited the presence of martensite phase and the particle reinforcements when studied under optical microscopy, field emission scanning electron microscopy (FESEM) supported by energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). Vickers’ microhardness testing of the modified surface affirmed a noteworthy improvement in hardness (2.13 times) with respect to the base metal (BM) for both the cases (ex-situ and in-situ) of Al2O3 reinforcement. Although, the hardness improvement was found to be similar in both the cases of reinforcement, but the depth of peak hardening was observed to be greater in case of matrix reinforcement by in-situ grown Al2O3 (∼1.25 mm) than the ex-situ added Al2O3 (∼0.9 mm), which is more useful for tribological requirements of industries.

Original languageEnglish
Article number125002
Number of pages9
JournalSurface and Coatings Technology
Early online date16 Oct 2019
Publication statusPublished - 25 Dec 2019
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2019 Elsevier B.V.


  • AlO dispersion
  • Composite layer
  • Steel
  • Surface hardening
  • TIG arcing

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry


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