Počet záznamů: 1  

Role of thermal spray processing method on the microstructure, residual stress and properties of coatings:an integrated study for Ni-5wt.% Al bond coats

  1. 1.
    0103252 - UFP-V 20040121 RIV US eng J - Článek v odborném periodiku
    Sampath, S. - Jiang, X. - Matějíček, Jiří - Prchlík, L. - Kulkarni, A. - Vaidya, A.
    Role of thermal spray processing method on the microstructure, residual stress and properties of coatings:an integrated study for Ni-5wt.% Al bond coats.
    [Vliv technologie žárového stříkání na mikrostrukturu, zbytková pnutí a vlastnosti povlaků: integrovaná studie Ni-5Al mezivrstev.]
    Materials Science and Engineering A Structural Materials Properties Microstructure and Processing. Roč. 364, 1-2 (2004), s. 216-231. ISSN 0921-5093. E-ISSN 1873-4936
    Grant ostatní: NSF(US) DMR9632570
    Výzkumný záměr: CEZ:AV0Z2043910
    Klíčová slova: bond coats, thermal spraying, microstructure
    Kód oboru RIV: JG - Hutnictví, kovové materiály
    Impakt faktor: 1.445, rok: 2004

    Thermal spray offers a variety of sub-sets of processing approaches to produce coatings. The various processes are classified based on the thermal spray source (from low velocity combustion spray to high temperature plasma jets) and method of material injection (in the form of powder, wire or rod). However, it is this intrinsic versatility which sets-up variations in characteristics of the applied coatings. Properties of thermally sprayed coatings, including process induced residual stress, are controlled by various parameters of the spraying process. This study examines three thermal spraying techniques with significantly different particle temperatures and velocities. They are air plasma spraying (APS), twin wire-arc spraying (TWA) and high velocity oxy-fuel (HVOF) spraying. For comparison purposes the recently developed cold spray processed materials were included in the study. For each method, in-flight particle diagnostics was performed; Ni-5 wt.%Al splats and deposits were fabricated and analyzed. Porosity, elastic modulus and thermal conductivity of the deposits were evaluated and correlated to the process variables. Using indentation at different loads and analysis of the indented region, stress-strain relationships for these coatings were obtained. Surprising differences in the properties were observed and were explained based on the fundamental variations in microstructure development. Through-thickness residual stress profiles in Ni-5 wt.%Al coatings on steel substrates were determined non-destructively by neutron diffraction. The stresses range from highly tensile in the APS coating to compressive in the HVOF coating. Various stress generation mechanisms-splat quenching, peening and thermal mismatch-are discussed with respect to process parameters and material properties.

    Vlastnosti žárových nástřiků jsou ovlivňovány parametry nanášecího procesu. Tato studie se zaměřila na čtyři technologie s výrazně odlišnými parametry (teplotou a rychlostí částic) – plazmové, obloukové, HVOF a kinetické stříkání. Byly diagnostikovány parametry částic za letu, struktura a mechanické vlastnosti vytvořených nástřiků. Závěrem jsou formulovány a diskutovány závislosti technologie-struktura-vlastnosti.
    Trvalý link: http://hdl.handle.net/11104/0010565

     
     
Počet záznamů: 1  

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