New Leaf Gilding Alloys: Physico-Chemistry, Colour, Mechanical Behavior

Evelyne Darque-Ceretti (1) , Marc Aucouturier (2) , Eric Felder (1) , Alain Burr (1) , Dominique Robcis (2) , Caroline Thomas (2)

1 CEMEF - Centre de Mise en Forme des Matériaux
2 C2RMF - Centre de recherche et de restauration des musées de France

In the frame of a systematic investigation on leaf gilding history and processes, in a research program intending to propose gold leaf alloys specially devoted to restoration, new gold alloys containing low concentration additions of In or Pd were designed and leaves were elaborated in collaboration with the goldbeater Dauvet. The influence of those elements on the colour change induced by alloying was obtained by colorimetry. The microstructural and metallurgical properties of the alloys were studied by scanning electron microscopy (SEM). The foils and leaves were characterized at the different manufacturing steps by EBSD (Backscattered Electron Diffraction), in order to evaluate the effect of the fabrication process on the microstructure and crystallographic texture. Surface segregation of the alloying element, influencing surface colour, was sometimes evidenced and discussed. The mechanical properties of the foils or leaves were measured by micro-and nano-indentation. The obtained properties and behaviour of the new alloys were compared with those of the leaves currently used for leaf gilding. The results conducted the beating company to consider developing new gold leaves production range(s) devoted specially for restoration application. As a result of the present investigation, new manufacturing and gilding procedures have been proposed.

Mots clés: Gold alloys; Leaf gilding; Colour; Mechanical properties; Texture

Domaines: Matériaux

Evelyne Darque-Ceretti, Marc Aucouturier, Eric Felder, Alain Burr, Dominique Robcis, et al.. New Leaf Gilding Alloys: Physico-Chemistry, Colour, Mechanical Behavior. International Journal of Conservation Science, 2015, Selected articles presented at GILT-EnArt 2015 International Conference on Gilding Materials and Techniques in European Art Evora, 25th – 27th of May 2015, 6 (Special Issue), pp.531-540. ⟨hal-01218667⟩