Enhancement of hardness and thermal stability of W-doped Ni3Al thin films at elevated temperature

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

1 Scopus Citations
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Author(s)

  • Chao Zhang
  • Kai Feng
  • Zhuguo Li
  • Fenggui Lu
  • Jian Huang
  • Yixiong Wu

Detail(s)

Original languageEnglish
Pages (from-to)575-583
Journal / PublicationMaterials and Design
Volume111
Publication statusPublished - 5 Dec 2016

Abstract

Nanocrystalline (NC) Ni3Al thin films have poor mechanical properties at a high temperature and in order to improve the thermal performance, it is necessary to develop novel micro- or nanostructures that endow the coatings with both high thermal stability and hardness. In this work, Ni3Al thin films with different W concentrations up to 12.5 at% are deposited on Si/SiO2 substrates by magnetron sputtering and then vacuum-annealed at 500 °C and 700 °C. Addition of W to the nanostructured Ni3Al thin films leads to grain refinement and high thermal stability. The hardness (H) of the film with 12.5 at% W annealed at 700 °C increases by 355% compared to pure Ni3Al. X-ray diffraction and transmission electron microscopy reveal non-equilibrium phases such as the amorphous phase and supersaturation solid solution in the films annealed at 500 °C. After annealing at 700 °C, the α-W phase precipitated in the fine nanocrystalline state plays a crucial role in the high thermal stability of the nano-grains as well as enhanced hardness. The results suggest that these durable Ni-based coatings are suitable for applications at high temperature.

Research Area(s)

  • Hardness, Nanocrystalline, Ni3Al, Thermal stability, W doped

Citation Format(s)

Enhancement of hardness and thermal stability of W-doped Ni3Al thin films at elevated temperature. / Zhang, Chao; Feng, Kai; Li, Zhuguo; Lu, Fenggui; Huang, Jian; Wu, Yixiong; Chu, Paul.K.

In: Materials and Design, Vol. 111, 05.12.2016, p. 575-583.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review