Influence of roughness on mechanical strength of direct bonded silica and Zerodur® glasses

Natacha Cocheteau (1) , Aurelien Maurel-Pantel , Frédéric Lebon (2) , Frédéric Mazerolle (2) , Iulian Rosu (1) , Sonia Ait-Zaid (3) , Isabelle Savin de Larclause (3)

1 M&S - Matériaux et Structures
2 LMA - Laboratoire de Mécanique et d'Acoustique [Marseille]
3 CNES - Centre National d'Études Spatiales [Toulouse]

Direct bonding is of particular interest for optical system manufacturing for spatial application. This process requires very precise physical and chemical preparations of surface, especially roughness controls. Thus, this paper proposes to understand and discuss the roughness influence on mechanical strength and bonding energy of an elementary mechanical structure after a room temperature bonding and an annealing at optimal temperature. First, surfaces are characterized and roughness is measured. At the same time, the performances of fused silica and Zerodur® glasses are compared. Then interface properties are measured using double shear and wedge tests. At the end of the paper, a discussion, based on literature models, is proposed to explain the existence of an optimum of roughness put in evidence in experimental results.

Mots clés: Direct bonding; Roughness; Double shear tests; Wedge tests; Bonding energy; Mechanical strength

Domaines: Mécanique des solides [physics.class-ph]

Natacha Cocheteau, Aurelien Maurel-Pantel, Frédéric Lebon, Frédéric Mazerolle, Iulian Rosu, et al.. Influence of roughness on mechanical strength of direct bonded silica and Zerodur® glasses. International Journal of Adhesion and Adhesives, 2016, 68, pp.87-94. ⟨10.1016/j.ijadhadh.2016.02.006⟩. ⟨hal-01420876⟩