Thesis. 1977. Mech.E.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by K. Subramanian. / Mech.E.

The cutting tool industry has evolved over the last half century to the point where an increasing range and complexity of cutting tools are available for metal machining. This highlighted a need to provide an intelligent, user-friendly system of tool selection and recommendation that can also provide predictive economic performance data for engineers and end-users alike. Such an 'expert system' was developed for a local manufacturer of cutting tools in the form of a relational database to be accessed over the Internet. A number of performance predictive models were reviewed for various machining processes, however they did not encompass the wide range of variables encountered in metal machining, thus adaptation of these existing models for an expert system was reasoned to be economically prohibitive at this time. Interrogation of published expert systems from cutting tool manufacturers, showed the knowledge-engineered principle to be a common approach to transferring economic and technological information to an end-user. The key advantage being the flexibility to allow further improvements as new knowledge is gained. As such, a relational database was built upon the knowledge-engineered principle, based on skilled craft oriented knowledge to establish an expert system for selection and performance assessment of cutting tools. An investigation into tapping of austenitic stainless steels was undertaken to develop part of a larger expert system. The expert system was then interrogated in this specific area in order to challenge by experiment, the skilled craft oriented knowledge in this area. The experimental results were incorporated into the database where appropriate, providing a user-friendly working expert system for intelligent cutting tool selection, recommendation and performance data.

There is an increasing demand for the exchange of important product and manufacturing information in a computer interpretable way. Large manufacturing companies are dependent on having access to the necessary information electronically. If they do not get information about their manufacturing resources from their vendors, they will buy their resources elsewhere, or they will have to create the information themselves. In the end, the cost of the manufactured products will increase to accommodate the cost increase from having to create, integrate, and maintain this information. In order to solve this problem, the use of international standards for product data is required. One area where such a standard is required is the area of cutting tools. This thesis describes the requirements for an international standard for the representation and exchange of cutting tool information and the resulting information model together with necessary reference data. The representation of cutting tool information using an international standard requires a generally applicable information model which is used together with a reference data library. The reference data provides the explicit, unambiguous concepts necessary for successful information exchange. ISO 13399, the international standard that is the result of this research project, uses P-Lib (ISO 13584) to define its reference data. To successfully use P-Lib in this way, requires some basic assumptions to be made, since P-Lib is originally developed for component catalogs. As a result of the chosen representation technique, the standard is capable of accommodating current and future developments of cutting tools, e.g. multi function tools. / QC 20100901

In today&amp / #8217 / s market conditions, higher tool life and durable cutting tools which can stand high cutting speeds are required in chip removal process. In order to improve the performance of cutting tools, coatings are employed extensively. Cubic boron nitride (cBN) is a new kind of coating material for cutting tools due to its outstanding properties and testing of cBN as a hard coating for machining have been increasing in recent years. However, there are some challenges such as compressive residual stress, poor adhesion and limiting coating thickness during the deposition of cBN on substrates. In this study, cubic boron nitride (cBN) coatings are formed on cutting tools from hexagonal boron nitride (hBN) target plates. For this purpose, a physical vapor deposition (PVD) system is utilized. PVD system works on magnetron sputtering technique in which material transfer takes place from target plate to substrate surface. Firstly, cBN coatings are deposited on steel and silicon wafer substrates for measurements and analyses. Compositional, structural and mechanical measurements and analysis are performed for the characterization of coatings. Next, several types of cutting tools are coated by cBN and the effects of cBN coatings on cutting performance are investigated. Finally, it can be said that cubic boron nitride coatings are successfully formed on substrates and the improvement of wear resistance and machining performance of cBN coated cutting tools are observed.

In this thesis, a systematic study has been carried out on the synthesis, characterization and applications of microcrystalline diamond (MCD) and nanocrystalline diamond (NCD) thin films deposited by the chemical vapor deposition (CVD) method. Firstly, an overview of diamond films synthesized from carbon-containing gas plasmas is presented. A parameter study was performed to grow diamond thin films. The transition from micro- to nanocrystallinity of diamond grains was achieved by controlling the Ar/Hydrogen gas ratio. The nanocrystallinity is the result of a new growth mechanism which involves the insertion of carbon dimmer into carbon-carbon and carbon-hydrogen bonds. Secondly, characterization of diamond films has been carried out by different techniques including electron microscopy, near edge X-ray absorption fine structure (NEXAFS), nanoindentation, and Raman spectroscopy. Unique properties of NCD, compared to those of MCD grown by conventional hydrogen rich plasma, have been observed and investigated. Thirdly, various applications of diamond films are discussed: a). Well-adhered MCD coatings have been deposited on WC-Co substrates with proper surface pretreatment. A diffusion barrier Cr/CrN/Cr was deposited on the cemented carbide substrate and the substrate was short peened with 150 micron friable diamond powders to achieve higher nucleation density and stronger adhesion strength; b). A nitrogen doped NCD based biosensor was fabricated for glucose sensing. Carboxyl functional group and conducting polymer (polyaniline) have been utilized respectively to electrochemically functionalize the diamond surface. A linear response to glucose concentration has been obtained from the electrode with good sensitivity and stability; c). A novel approach to synthesize NCD wires has been developed for the first time. The NCD coating was successfully coated on Si nanowires (SiNWs) to form NCD wire with diameter around a few microns. This study opens a whole new area for applications based on diamond wires such as neural transmission electrodes, field emission emitters, and electrochemical electrodes with improved properties

Metal cutting is an important process used to manufacture components with machined surfaces or holes. Due to the wide usage o f this manufacturing process, research with the aim to optimize the cutting processes is important. Improving cutting techniques even mild)s can result in major cost savings in high volume production. Better machining practices will result in products of better precision and of greater useful life . Benefits can also be had from increasing the rate of production and producing a bigger variety of .. products with the tools available. The area of metal cutting has been researched widely by people like Tourrett, Taylor, Cohen, Davis and many others to find improved techniques and methods. This project was conducted to improve cutting conditions by ensuring that the tool geometry is always optimal . The effect of tool geometry on cutting performance has been discussed in detail by many researchers, but the practical application of these theories is an area that needs further attention. For this project a device was developed to vary the tool geometry with stepper motors on command from the controller. This device was used for research into the viability of varying tool geometry during machining to obtain different cutting conditions. Stepper motors ensure high accuracy in the control of tool geometries. The ease of controlling stepper motors, also simplified the controlling program and communication devices a lot. Rotating the stepper motors results in rotation o f the tool holder around the tool tip. Tool angles are varied without affecting the other cutting parameters like the depth o f cut, metal removal rate and cutting speed. With these cutting parameters staying the same, the change in tool geometry should result in a change in the power consumed during cutting and the force required for cutting . Other measurements for cutting performance like temperature of the tool and workpiece and the acoustic print of the tool will also change. Results prove that cutting force measurement can be used effectively to measure the optimal cutting conditions . The back rake angles and side rake angles have the biggest influence of all the tool angles on metal cutting . This is demonstrated by a number of researchers [28] as discussed in section 2 . 2. This thesis proves how the on-line changing of tool geometry, ensures the optimal cutting conditions. / Thesis (Ph.D.-Mechanical Engineering)-University of Natal, 1996.

The phenomenal growth rate for the use of engineering ceramics is attributed to successful scientific responses to industrial demand. These materials are replacing metal and its alloys in diverse applications from cutting tools and heat engine components to integrated circuits. Joining technology plays a vital role in this changing and evolving technology as success and failure comes with breaking new barriers. It is important to improve existing techniques and to develop new techniques that reliably join simple shape components to form complex assemblies or join dissimilar materials such as metal to ceramic. Joining of ceramics is not simple due to their high chemical stability and low coefficient of thermal expansion (CTE). Joining between metal and ceramic is usually carried out at elevated temperatures and upon cooling thermal residual stresses are induced that lead to joint failure or poor strength. Most metal-ceramic joints cannot be used over 500°C primarily due to the low melting temperature of the interlayer. This investigation was concerned with the successful joining for higher temperature applications (above 500°C) of two dissimilar high temperature oxidation and corrosion resistant materials, Fecralloy and silicon nitride. The primary focus was on the effects of process conditions upon the microstructure and mechanical properties of the joint and to also study/identify the joining mechanism. Two novel techniques were employed to join successfully the metal to ceramic. The first was by use of a thin Cu foil that did not remain after joining. Joining occurs by a process that results in partial melting of the Fecralloy interface, where Fe, Cr, Al and Cu reactively infiltrate into the silicon nitride. This liquid mixture causes partial dissolution of the silicon nitride interface, where Si and N diffuse into the Fecralloy. A thin reaction product layer was formed at the silicon nitride interface and our results suggested that this was AIN. The free surface Si and porosity of the silicon nitride along with the eutectic temperatures above 1100°C are all vital for this joining process. The highest average shear strength of a Fecralloy-silicon nitride joint produced by the method was 67.5 MPa. The second route was that of a powder metallurgy one, where cold pressed Ni-Al (1:1 molar) compacts were used to join successfully the Fecralloy to silicon nitride. The formation of NiAl from its constituents is highly exothermic and this is initiated between 500-650°C. The high temperature reached causes partial melting of the Fecralloy interface and dissolution/reactive wetting at the silicon nitride interface. Mostly Fe infiltrates the NiAl improving room temperature ductility, fracture toughness and yield strength. Molten Al from the interlayer reacts and wets the silicon nitride interface with small amount of infiltration and no reaction product forming. The reaction synthesis of NiAl was studied using DTA and TGA, where the effects of Ni particle size and heating rate were investigated. This joining process is highly dependant upon process conditions, the most important of which are applied pressure, heating rate and Ni/A1 particle size. The highest average shear strength attained was 94.30 MPa and this is attributed to good interfacial bonding, high pressure, moderate process temperature and dwell time. The exothermic formation of the NiAl interlayer that is densified and monophase was paramount for this joining process. The Bansal-Doremus kinetic model for evaluating the kinetic parameters from non-isothermal DTA data was shown to be valid. The results obtained were identical to those by other authors who used a different model and approach.

Thesis (MEng) - School of Engineering and Science, Swinburne University of Technology, 2004. / Thesis submitted for the degree of Master of Engineering by Research, School of Engineering and Science, Swinburne University of Technology, 2004. Typescript. Includes bibliographical references: p. 116-122.

Les céramiques à base d’Al2O3 et de 3Y-ZrO2 à structures submicroniques présentent, au vu de leurs propriétés physiques et mécaniques, un fort potentiel pour l’usinage de composites en bois. Neuf nuances ont été développées par coulage-gélification (CG) et par pressage isostatique à froid (CIP). Elles ont ensuite été testées en usinage dans des conditions industrielles de coupe. L’objectif de la thèse a été la compréhension, à partir de ces résultats, des mécanismes d’usure, afin d’identifier les propriétés physiques et mécaniques nécessaires pour l’usage d’un matériau nouveau pour cette application. Des outils prototypes de fraisage et de tournage ont été conçus. L’état d’endommagement et les contraintes résiduelles dans la céramique, dus aux étapes de fabrication des prototypes, ont été déterminés. Les résultats des expérimentations de coupe montrent que différents mécanismes opèrent sur l’usure des céramiques. Pour les nuances d’alumine, l’usure de l’arête se fait par arrachement cyclique de grains, tandis que les nuances à base de zircone se déforment plastiquement. Il apparaît que les propriétés physiques, telles que la taille de grain et la densité, sont prédominantes sur les propriétés mécaniques. L’utilisation de céramiques à structure submicronique avec des densités supérieures à 99 % améliore les performances en usinage. C’est la nuance Al2O3-10 % ZrO2 produite par CG qui a montré la meilleure résistance à l’usure. Lors de l'affûtage et de la coupe, l'oxyde de zirconium non stabilisé opère un changement de phase qui induit des contraintes de compression au sein de la microstructure et augmente ainsi la résistance micromécanique des joints de grain. / High mechanical properties of sub-μm grain Al2O3 and 3Y-ZrO2 present high potential for the cutting of wood-based materials. Nine grades were produced by gelcasting (GC) and cold isostatic pressing (CIP). They were tested in real industrial conditions. From those results, this thesis’ aim was to highlight the wear mechanisms in cutting, and then deduce major physical and mechanical properties that are task of material development. Consequently, prototypes for cutting trials have been developed. As a result, the manufacturing of prototype tools, X-Ray diffraction, analytical and numerical investigations were performed to quantify residual stress that occurred in ceramic. Observation of the results of experimentations in machining showed different wear modes. For alumina’s grade, single grain pull-out was the main wear mechanism of the cutting edge, while microplastic deformation occurred in zirconia’s composition. Physical properties of ceramic structure, like grain size and density, are more important than mechanical properties. To improve cutting lifetime, density must be higher than 99%, with a structure with sub-μm grain size. It appeared that there was a predominant role of micromechanical stability while cutting abrasive materials. Fracture toughness or thermal shock resistance seem to have marginal influence when ceramic were produced by low-defect process like GC. Regarding all ceramic grades the Al2O3-10ZrO2 made by GC showed the highest wear resistance in machining. Unstabilized zirconia brought micromechanical stability between grains of the cutting edge while working.

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