Promoteur : Prof. Edouard RIVIERE –
Co-promoteur : Prof. François DUCOBU

Résumé :

Micro-manufacturing has been booming for several decades in the aeronautics, medical, space and
luxury sectors. Manufacturing processes are evolving to satisfy this growing demand and no sector is
shielded. A new manufacturing chain is emerging based on the combination of existing processes.
These processes can be used simultaneously or sequentially to increase productivity but also the
precision of the manufactured parts. They are grouped under the name of hybrid manufacturing
processes. Hybridization of machining with a cutting tool and a laser results in a hybrid platform for the
micro-manufacturing market. Indeed, the size of the milling tool strongly limits the miniaturization.
Finishing with a laser beam, whose spot size can be ten times smaller than the diameter of a cutting
tool, allows to machine complex parts that are unachievable with a cutting tool.
The manufacture of advanced ceramics, which is one of the most difficult type of materials to machine,
also follows the same market trend. Ceramics are brittle materials that must be shaped with adapted
tools. Nevertheless, the manufacturing chain used in modern industry makes it possible to improve the
productivity. Such a manufacturing chain consists in shaping a machining blank by compacting powders
with a binder. Successively, this machining blank is machined with a cutting tool before being placed in
a furnace to sinter the machined part to give it its final dimensions and mechanical properties. Machining
in a non-sintered state is called Green Ceramic Machining (GCM). This thesis consists in examining
whether the hybrid combination of machining with a cutting tool and a laser beam is possible for the
GCM.
The present research is divided into three main areas:
▪ GC Milling: The machining parameters used in modern industry are empirically determined. One
solution used in the industry is to pre-sinter the machining blank for it to give intermediate
properties facilitating machining. The goal of this part is to study the interaction between the
cutting tool and the material in a not totally sintered state (white and green states) to develop a
method for determining the machining parameters.
▪ GC Laser Machining: Laser machining is not used because heat exchange could cause local
sintering during machining. That part studies the interaction of the material with a laser beam to
determine machining parameters that do not cause local sintering during the material removal
operation.
▪ GC Hybrid Machining: The hybridization of both processes requires an adequate machining
blank to increase productivity while maintaining the integrity of machined components. That part
studies the green composition but also highlights the impact on the parts obtained after
sintering. Mechanical properties as well as surface integrity are investigated in that part.
The combination of the research carried out in these three parts allows to evaluate if the capacity of
this hybrid platform can be profitable for the modern industry to produce ceramic micro-components.