Microstructure and Phase Formation in a Rapidly Solidified Laser-Deposited Ni-Cr-B-Si-C Hardfacing Alloy

Ismail Hemmati*, Vaclav Ocelik, Kornel Csach, Jeff Th M. de Hosson

*Bijbehorende auteur voor dit werk

    OnderzoeksoutputAcademicpeer review

    44 Citaten (Scopus)
    532 Downloads (Pure)

    Samenvatting

    In this study, microstructural evolutions and phase selection phenomena during laser deposition of a hardfacing Ni-Cr-B-Si-C alloy at different processing conditions are experimentally investigated. The results show that even minor variations in the thermal conditions during solidification can modify the type and morphology of the phases. Higher undercoolings obtained at faster cooling rates suppressed the primary borides and encouraged floret-shape mixtures of Ni and Cr5B3 via a metastable reaction. Variations in the boride phases are discussed in terms of nucleation-and growth-controlled phase selection mechanisms. These selection processes also influenced the nature and proportion of the Ni-B-Si eutectics by changing the amount of the boron available for the final eutectic reactions. The results of this work emphasize the importance of controlling the cooling rate during deposition of these industrially important alloys using laser beam or other rapid solidification techniques. (C) The Minerals, Metals & Materials Society and ASM International 2013

    Originele taal-2English
    Pagina's (van-tot)878-892
    Aantal pagina's15
    TijdschriftMetallurgical and Materials Transactions A
    Volume45A
    Nummer van het tijdschrift2
    DOI's
    StatusPublished - feb-2014

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