Surface modification, microstructure and mechanical properties of investment cast superalloy

• Autorzy: Zielińska M. , Kubiak K. , Sieniawski J.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The aim of this work is to determine physical and chemical properties of cobalt aluminate (CoAl2O4) modifiers produced by different companies and the influence of different types of modifiers on the grain size, the microstructure and mechanical properties of high temperature creep resisting superalloy René 77. Design/methodology/approach: The first stage of the research work took over the investigations of physical and chemical properties of cobalt aluminate manufactured by three different companies: Remet, Mason Color and Permedia Lublin. There were determined the grain size distribution of cobalt aluminate powder, the average diameter of the powder particles, phase composition, cobalt contamination. In the next step, the ceramic moulds were made with different kind of cobalt aluminate (Mason Color, Remet, Permedia Lublin) and its concentration (0.5%) in the primary slurry. The samples of stepped and cylindrical shape were poured in the ceramic moulds prepared earlier. The average grain size of the . phase, was determined on the stepped samples. The microstructure investigations let to examine the influence of the surface modification on the morphology of . ‘ - phase and carbides precipitations. Samples were turned from cylindrical castings for mechanical properties investigations: creep tests. Findings: Modification of the face coat of ceramic mould results in the reduction of the grains size of . matrix and disintegration of carbide precipitates. It results in the improvement of mechanical properties of the alloy. On the grounds of the obtained results, it was found that the type of used modifier influenced the grain size of the alloy and its mechanical properties. Research limitations/implications: The established physical and chemical properties of modifier let to get better control of grain size of the castings and their quality what will result in decrease of defective products. Originality/value: It was proved that the effectiveness of cobalt aluminate modifier as an inoculant depends not only on its concentration in ceramic slurry but on its chemical composition. The researches allowed to find the optimal concentration of Co in CoAl2O4 to produce casting elements made from superalloy René 77.

Słowa kluczowe

EN

nickel superalloys; surface modification; cobalt aluminate; grain refinement; mechanical properties

PL

nadstopy niklu; modyfikacja powierzchni; glinek kobaltu; rafinacja ziaren; właściwości mechaniczne

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2009
• Tom: Vol. 35, nr 1
• Strony: 55--62
• Opis fizyczny: Bibliogr. 20 poz., rys., tabl.

Twórcy

autor

Zielińska M.

autor

Kubiak K.

autor

Sieniawski J.

• Department of Materials Science, Faculty of Mechanical Engineering and Aeronautics, Rzeszow University of Technology, Al. Powstańców Warszawy 8, 35 - 959 Rzeszów, Poland,

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