Dilatometric Analysis for Investigating Age Hardening in a Commercial Precious Metal Dental Alloy

    Volume 6, Issue 2 (February 2009)

    ISSN: 1546-962X

    CODEN: JAIOAD

    Published Online: 8 January 2009

    Page Count: 12


    Rivolta, B.
    Polo Regionale di Lecco, Politecnico di Milano, Lecco,

    Gerosa, R.
    Polo Regionale di Lecco, Politecnico di Milano, Lecco,

    Pinasco, M. R.
    Sezione di Chimica Inorganica e Metallurgia, Dipartimento di Chimica e Chimica Industriale, Università di Genova, Genova,

    Pellati, G.
    Sezione di Chimica Inorganica e Metallurgia, Dipartimento di Chimica e Chimica Industriale, Università di Genova, Genova,

    (Received 26 November 2007; accepted 20 November 2008)

    Abstract

    Age hardening in a commercial precious metal dental alloy based on the Au–Cu–Ag system with platinum addition was investigated by light optical microscope, scanning electron microscope, energy dispersion x-ray system microanalysis, image analysis, hardness measurements, and dilatometric tests. Dilatometric tests are known to give important information for optimizing the heat treatment parameters of metallic materials but are seldom used in studying the hardening of precious alloys. Nonisothermal dilatometric tests were used to point out the temperature range within which the microstructural hardening transformations occur, while isothermal tests were adopted to study the kinetics of each transformation. The macrohardness and microhardness measurements contributed to the understanding of the nature of the observed transformations, together with the microstructural analysis. We concluded that hardening is mainly due to order-disorder transformations taking place in the matrix. The identified optimal parameters were used for the heat treatment of a lost wax casting alloy prepared according to the traditional procedures for prosthesis manufacturing.


    Paper ID: JAI101581

    DOI: 10.1520/JAI101581

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    Author
    Title Dilatometric Analysis for Investigating Age Hardening in a Commercial Precious Metal Dental Alloy
    Symposium , 0000-00-00
    Committee B02