Cavitation erosion and corrosion behaviour of laser surface alloyed MMC of SiC and Si3N4on Al alloy AA6061

Hau Chung Man, C. T. Kwok, Tai Man Yue

Research output: Journal article publicationJournal articleAcademic researchpeer-review

79 Citations (Scopus)

Abstract

Laser surface alloying of SiC/Si3N4on AA6061 aluminium alloy was carried out using a 2-kW CW Nd-YAG laser. Different ratios of SiC and Si3N4powders were mixed and the layers were preplaced by pasting. Subsequent laser surface melting of the layers gave a surface metal matrix composite (MMC). The microstructure, chemical compositions and phase identification of the modified layers were examined using scanning electron microscopy (SEM), energy disperse X-ray spectroscopy (EDX) and X-ray diffractometry (XRD), respectively. The laser surface alloyed MMCs of AA6061-SiC and AA6061-Si3N4consisted of small amounts of Al4C3/Al4SiC4and A1N, respectively. For specimens alloyed with 100% Si3N4(AA6061-Si3N4), the cavitation erosion resistance R(e) was improved by three times as compared to the AA6061 alloy whereas there was no significant improvement in R(e) of the specimen alloyed with 100% SiC (AA6061-SiC). The surface hardness of the specimens alloyed with SiC/Si3N4was increased seven times. All the laser alloyed specimens with SiC/Si3N4showed a decrease in pitting resistance and absence of passivity owing to the aluminium-ceramic interfaces, which favour pit initiation or hindered passivity.
Original languageEnglish
Pages (from-to)11-20
Number of pages10
JournalSurface and Coatings Technology
Volume132
Issue number1
DOIs
Publication statusPublished - 1 Oct 2000

Keywords

  • Aluminum alloy
  • Laser
  • Si N 3 4
  • SiC

ASJC Scopus subject areas

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

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