Le micro-fraisage (diamètre fraise < 1 mm) permet l’usinage précis de structures en 3D, à des dimensions micrométriques, dans desmatériaux d’ingénierie, se plaçant aux frontières de deux mondes : d’une part, le fraisage traditionnel appelé « fraisage macro » et d’autre part,la micro-fabrication et ses techniques dites de « salle blanche ».L'étude innovante porte sur le micro-fraisage d’aciers inoxydables 316L avec des micro-fraises cylindriques en carbure de tungstèneavec un équipement industriel (machine outil commercialisée et non optimisée) permet d’accentuer les nombreuses difficultés technologiquesliées à la mise en oeuvre du micro-fraisage et d’effectuer directement un transfert de compétences vers l’industrie. L’acier 316L(biocompatible, réputé de difficilement usinable) n’a jamais été étudié en micro-fraisage.L’étude aborde, au travers de neufs ratios caractéristiques du micro-fraisage, les problématiques de choix de moyens et de méthodespour caractériser la technique du micro-fraisage.Après analyses des paramètres de l’étude et des caractérisations des usinages, la définition géométrique optimale d’une micro-fraiseinnovante est proposée. Sa tenue en service est validée par des tests en usinage dans l’acier 316L, répondant ainsi, à une problématique decoupe négative à basse vitesse de coupe avec des effets d’échelle du matériau.Une originalité de l’étude est d’aborder l’effet de la population inclusionnaire visant à améliorer l’usinabilité. En comparant lesrésultats obtenus par micro-fraisage de 2 nuances d’acier 316L, la population inclusionnaire de l’acier 316L n’est pas identifiée comme unfacteur améliorant l’usinabilité à l’échelle de la coupe micro. / The micro-milling ( tool diameter < 1 mm) target the precise machining of 3D structures to micrometric dimensions, in engineeringmaterials, to be placed at the borders of two worlds : the one hand , the traditional milling called "macro milling" and other hand, the microfabricationand its so-called "clean room" techniques.The innovative study focuses on the micro-milling of 316L steel with carbide micro end mills with industrial equipment (machine toolmarketed unoptimized) can caricature the many technological challenges related to the implementation of the micro-milling and make a directtransfer of skills to the industry. 316L steel (biocompatible, reputed difficult to machine) has never been studied in micro-milling.The study looks at ratios through new features of the micro-milling, the problems of choice of means and methods to characterizemicro-milling.After analysis study parameters and machined parts, the optimal geometric definition of an innovative micro end mill is proposed.Service behavior is validated by testing machining in 316L steel, responding to a question of negative cutting with low cutting speeds andscale effects of the material.An originality of the study is to address the effect of the inclusion population to improve machinability. Comparing the resultsobtained by micro-milling two 316L steel grade, the inclusion population of 316L steel is not identified as a factor improving themachinability cutting at micro scale.

The objective of this diploma thesis are new design materials in a view of their structure, properties, manufacture,partitions, applications and possibili-ties of effective machining them Ceramics are used in the field of design applications more often than before. They are in form of compact parts and in form of thin coatings on the surface of metal parts. Fast development of constructive applications requires the same progress rate of machining ma-chines innovations and development of new methods of effective machining these materials, too. The aim is to produce parts of demanded shapes, dimensions and surface quality at affordable costs. Ceramics guarantee long terming durability and reliability. The evaluation of ceramics grinding tests from the point of view of cutting forces and surface quality of the machined faces are presented in the last part of the diploma thesis.

This document is final report of an expertise project lead for ALPHA Company. The project focuses on the machinability characterization and comparison of various lamellar cast irons metallurgies. The comparison is performed in order to improve the casting process and the cast irons composition of brake and hub disk, to increase their machinability. The characterization of the metallurgies was made by tool life test with measurements of the cutting forces. Hardness and surface roughness measurements were performed too. Several Silicon nitride tools were tested. First an adjustment test has been performed to validate the machining parameters, and the methodology of characterization. Secondly, a reference test on Alpha’s cast iron brought reference data for the comparison of the various metallurgies to be tested. This test has improved the method of characterization. Cutting forces recording appeared as the most relevant and irrelevant measurements such as surface roughness were eliminated from the method. A test performed on a second cast iron showed that it has a lower machinability. Project succeeded to characterize and compare cast irons’ machinabilities, allowing the improvement of the composition by further tests.

Dans l’industrie, les fabricants tendent à limiter la lubrification conventionnelle lors de l’usinage et s’orientent de plus en plus vers la microlubrification (MQL : Minimum Quantity Lubrication) pour des raisons économiques, écologiques et pour respecter la santé des opérateurs. Une très faible quantité de lubrifiant de faible pression nécessite une conception optimale des canaux internes de l’outil afin de limiter les pertes de charges et avoir les avantages de la microlubrification. Premièrement, une revue bibliographique introduit l’étude en présentant les avantages qu’induit le passage à la microlubrification. Par la suite, quelques conceptions d’outils avec une lubrification interne qui vise la face de coupe ou la face de dépouille de la plaquette sont passées en revue. / In machining industry, manufacturers tend to limit conventional lubrication and are moving increasingly towards Minimum Quantity Lubrication (MQL) for economic and ecological reasons, and with a view to safeguarding operator health and safety. A very small amount of lubricant at low pressure requires optimized design of the tools internal channels in order to minimize pressure drops and gain benefit from MQL. First, a literature review introduces the study by presenting the benefits induced by switching to MQL. Thereafter, some tool designs with internal lubrication for rake face or flank face lubrication are presented.