The main goal of this work is the analysis of manufacturing costs for the component of wheel´s blower. Followed by setting up the size of specific cutting force for milling operation of the titanium alloy Ti-Al6-Mo2-Cr2-Fe-Si, the used tool was a milling cutter which is made out of sintered carbide with conical and spherical face. The final values which are at intervals of 1500 to 1800 MPa were compared with the values of the Sandvik Coromant firm kc = 1690 MPa, for titanium alloy with the strenght in tension Rm = 1050 MPa.

The thesis is focused on the characteristic of coating methods and their division, on the morphology of defects and cause of wear in coated cutting tools of sintered carbides. The experimental part is focused on a comparing cutting performance testing of indexable cutting inserts coated with nanocrystaline composite TiAlSiN at the longitudinal turning.

The aim of the thesis is to analyze the production costs and optimize cutting conditions for high-feed face milling of titanium alloy Ti6Al4V. In the experiment were changed cutting conditions, such as cutting speed vc and feed speed vf. During the experiment were checked cutting forces by dynamometr. Furthermore, surface roughness and tool wear is observed.

Thesis aims on efficient milling of stainless steels. Groups of these steels are characterized and their machinability is analyzed in theoretical part of this thesis. In the practical part of thesis were face milled stainless steels ČSN 17 240.4 a ČSN 17349.4. There are evaluated edge durability, roughness of surface, loading of total cutting force and effectiveness of test tools.

This dissertation thesis is focused on the analysis of specific cutting forces and accompanying effects during machining of the new materials, composite materials. The experimental part is split up to two main chapters. In the first chapter, the development of specific cutting forces is analyzed in detail when cutting conditions are changing. The experimental machining of glass/polyester and carbon/epoxy composites is described for fibers orientations 0 a 90 (ie, the orientation of the fibers in the feed rate direction and perpendicular to the feed rate direction). The influence of the cutting tool flank wear on the specific cutting force is investigated further. The last section compares the values of specific cutting forces when machining with carbide milling tools deposited by different types of coating. The second chapter describes the measurement of sound spectrums generated by cutting process, sound maps creating and finding possible correlations between dominant frequencies of the sound and the specific cutting forces, or the cutting tool flank wear. The measurements are described for the cases of machining steel 15 260.7 and glass-polyester composite material.

Dans le cadre du projet ECOMEF visant à éco-concevoir un outil de bûcheronnage pour la mécanisation des peuplements feuillus, les travaux de thèse présentés ici concernent la modélisation du système bois court, et plus particulièrement des opérations d’abattage et de façonnage (ébranchage et billonnage). Des modèles ont été développés afin d’étudier la transmission de l’effort d’entraînement au tronc par les rouleaux ainsi que l’opération d’ébranchage par choc. Parallèlement, différents démonstrateurs ont été réalisés afin de mener un certain nombre d’essais expérimentaux, qui ont permis, d’une part, une meilleure compréhension des phénomènes étudiés, et d’autre part le recalage des modèles théoriques. Enfin, une simulation dynamique multicorps a été mise en place, afin d’étudier plus précisément l’adaptation de différentes architectures cinématiques de châssis articulés aux flexuosités du tronc rencontrées dans les essences feuillues. Celle-ci intègre l’ensemble des modèles analytiques développés et permet une approche globale à travers l’interaction des modèles les uns avec les autres. / The research work presented here and realized within the framework of the ECOMEF project - which aims to develop a harvester head more specifically designed to process and fell broad-leaved trees – focuses on the modeling of the cut-to-length logging process, and particularly on the felling and processing (delimbing and bucking) operations. Several models have been developed in order to study the transmission of the feed force to the trunk or the delimbing process. In the same time, different benches have been designed in order to carry out experimental tests that allow a better understanding of the considered phenomenons as well as the experimental characterization of the models’ parameters. Finally, a multi-body dynamic simulation has been developed, in order to study the adaptation of different kinematic architectures of articulated frames to the crooked trunks specific to broad-leaved trees. This simulation contains each analytic model and allow a global study of the phenomenon by considering the interaction between each model.

The industrial development of metal cutting processes in gear manufacturing aims at continuously increasing productivity, including increased tool reliability. Basically, the parameters that have an influence on the cutting processes should be known and possible to control. Gear manufacturing is highly important for the automotive industry. The prevalent manufacturing method is gear hobbing with hobs consisting of solid Powder Metallurgical High Speed Steel (PM HSS) with Physical Vapor Deposited (PVD) coatings. The hob teeth have to be reconditioned before wear reaches such levels that the gear quality becomes impaired. Such wear often results in a total breakdown of the tool. One crucial reason for this is that hobbing processes for the present often lack reliability; which makes it difficult for the gear manufacturers to predict the tool wear on the hob teeth and decide when the tool should be replaced in order to avoid severe damages. A consequence of catastrophic tool wear is that it leads to an instantaneously changed geometry of the cutting edge, which in turn implies that the machined gears do not comply with the stipulated properties on the machined gear products. A single tooth milling test (STMT) with tools of PM-HSS in a conventional milling machine has been developed in this research project, aiming at characterizing the effect of tool preparation on the type of wear mechanism. The experience and conclusions from these tests may probably be transferred to real PM-HSS hob tooling (HT). The advantages of such a test, compared to a real gear hob test, are primarily the cost reductions and time saving aspects with respect to both the design and the manufacturing of the cutting teeth The research presented in this thesis is based on experimental investigations and theoretical studies of significant parameters, i.e. the surface roughness and edge rounding, contributing to the robust and reliable design of a PM-HSS cutting tool. The research work has in addition to, the development of the milling test method, also comprised development of measuring methods and a simulation model based on the Finite Element Model (FEM). / <p>QC 20121105</p>

Planning of optimal toolpath, cutter orientation, and feed rate for 5-axis Computer Numerical Control (CNC) machining of curved surfaces using a flat-end mill is a challenging task, although the approach has a great potential for much improved machining efficiency and surface quality of the finished part. This research combines and introduces several key enabling techniques for curved surface machining using 5-axis milling and a flat end cutter to achieve maximum machining efficiency and best surface quality, and to overcome some of the key drawbacks of 5-axis milling machine and flat end cutter use. First, this work proposes an optimal toolpath generation method by machining the curved surface patch-by-patch, considering surface normal variations using a fuzzy clustering technique. This method allows faster CNC machining with reduced slow angular motion of tool rotational axes and reduces sharp cutter orientation changes. The optimal number of surface patches or surface point clusters is determined by minimizing the two rotation motions and simplifying the toolpaths. Secondly, an optimal tool orientation generation method based on the combination of the surface normal method for convex curved surfaces and Euler-Meusnier Sphere (EMS) method for concave curved surfaces without surface gouge in machining has been introduced to achieve the maximum machining efficiency and surface quality. The surface normal based cutter orientation planning method is used to obtain the closest curvature match and longest cutting edge; and the EMS method is applied to obtain the closest curvature match and to avoid local gouging by matching the largest cutter Euler-Meusnier sphere with the smallest Euler-Meusnier sphere of the machined surface at each cutter contact (CC) point. For surfaces with saddle shapes, selection of one of these two tool orientation determination methods is based on the direction of the CNC toolpath relative to the change of surface curvature. A Non-uniform rational basis spline (NURBS) surface with concave, convex, and saddle features is used to demonstrate these newly introduced methods. Thirdly, the tool based and the Tri-dexel workpiece based methods of chip volume and cutting force predictions for flat-end mills in 5-axis CNC machining have been explored for feed rate optimization to achieve the maximum material removal rate. A new approach called local parallel slice method which extends the Alpha Shape method - only for chip geometry and removal volume prediction has been introduced to predict instant cutting forces for dynamic feed rate optimization. The Tri-dexel workpiece model is created to get undeformed chip geometry, chip volume, and cutting forces by determining the intersections of the tool envelope and continuously updating the workpiece during machining. The comparison of these two approaches is made and several machining experiments are conducted to verify the simulation results. At last, the chip ploughing effects that become a more serious problem in micro-machining due to chip thickness not always being larger than the tool edge radius are also considered. It is a challenging task to avoid ploughing effects in micro-milling. A new model of 3D chip geometry is thus developed to calculate chip thickness and ploughing volume in micro 5-axis flat-end milling by considering the minimum chip thickness effects. The research forms the foundation of optimal toolpath, cutter orientation, cutting forces/volume calculations, and ploughing effects in 5-axis CNC machining of curved surfaces using a flat-end mill for further research and direct manufacturing applications. / Graduate / 0548 / luoshan@uvic.ca

Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The aim of this work is to study the effect of silicon content in the machinability of CBA s (Compania Brasileira de Aluminio) 6351 aluminum alloy measured through cutting force and surface finish. In a first moment the effect of depth of cut (ap), cutting speed (vc), feed rate (f) and silicon content (% Si) on the machinability were investigated. The machining process used was turning operation with no cutting fluid. In a second part of the tests it was used MQF (60 l/h) and over head flood in experimental tests with constant depth of cut. For each set of parameters it was acquired values of cutting forces and surface roughness with two repetitions, adopting a 3k design of experiments. The results showed that the silicon content has significant effect in the machinability of the studied alloy compared to the others parameters investigated. Keywords: / O objetivo deste trabalho é a verificação da influência do teor de silício na composição da liga de alumínio 6351 da empresa CBA (Compania Brasileira de Alumínio) na usinabilidade avaliada através da medição da força de corte e do acabamento superficial. Em uma primeira etapa foi analisado estatisticamente o efeito dos parâmetros de corte, profundidade de corte (ap), velocidade de corte (vc), avanço (f) e porcentagem de silício (% Si) na força de corte e rugosidade superficial durante ensaios de torneamento cilíndrico externo sem aplicação do fluido de corte. Em uma segunda etapa dos ensaios utilizou-se fluido de corte aplicado através de MQF (60l/h) e jorro, mantendo constante a profundidade de corte e variando velocidade de corte e avanço. Para cada uma das combinações de parâmetros de corte foram adquiridos valores de força de corte e rugosidade superficial com duas réplicas para cada ensaio, adotando um planejamento fatorial 3k. Analise estatística de variância (ANOVA) mostrou que a porcentagem de silício exerce influência significativa nos parâmetros de usinabilidade avaliados da liga estudada quando comparado com avanço, velocidade de corte e profundidade de corte. / Mestre em Engenharia Mecânica

This thesis deals primary with design of a woodworking machine focused on woodworking technology by cutting – rip saw. The introduction to the work is get to acquainted with the material to be processed – wood, and also the search of associated machines with the same technology of workpiece processing. Next part is focused on the safety of machining on woodworking machines and the individual safety features that the machines must contain are also analyzed. From this survey, a saw model with all the necessary features is created. The conclusion of the thesis is devoted to the risk analysis of the proposed machinery and their reduction.