Development of cubic boron nitride (cbn) coating process for cutting tools

Download
2009
Cesur, Halil
In today’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.

Suggestions

Development of postprocessor, simulation and verification software for a five-axis CNC milling machine
Cengiz, Ender; Gökler, Mustafa İlhan; Department of Mechanical Engineering (2005)
Five-axis CNC milling machine tools bring great facility to produce complex workpieces with increased dimensional accuracy and better surface quality in shorter machining times. However, kinematics of five-axis machine tools has a complex form which makes it difficult to operate these machine tools properly. The difficulty arises from the complexity of NC-Code generation and tool path verification. Collision of machine tool or setup components with each other is a severe problem in five-axis machining opera...
An investigation on dynamic contact parameters in machining center spindle tool assemblies
Özşahin, Orkun; Özgüven, Hasan Nevzat; Department of Mechanical Engineering (2008)
In machining centers, with the increasing trends in high precision machining, chatter has become an important problem which results in poor surface finish and low material removal rate. Chatter can be avoided with stability diagrams which provide the stable regions in the machining process for the depth of cut and spindle speed combinations. In order to obtain stability diagrams, tool point frequency response function (FRF) of the system should be obtained. Throughout this study, contact parameters which ar...
Analysis and modelling of machine tool dynamics and cutting stability during operation
Özşahin, Orkun; Özgüven, Hasan Nevzat; Budak, Erhan; Department of Mechanical Engineering (2014)
Self-excited vibrations of machine tools during cutting result in process instability, poor surface finish and reduced material removal rate. In order to obtain stability lobe diagrams to avoid chatter vibration, tool point frequency response function (FRF) must be determined. In classical machine tool studies, tool point FRF is obtained experimentally or analytically for the idle state of the machine. However, during cutting operations, discrepancies are frequently observed between the stability diagrams o...
Development of High Fracture Toughness Hard Coatings
Kaygusuz, Burçin; Özerinç, Sezer; Kazmanlı, Muhammet Kürşat; Department of Micro and Nanotechnology (2021-9-2)
Improving the machining performance of cutting tools is critical for increasing product quality and decreasing production cost and time. For this purpose, hard coatings on cutting tools are widely utilized in the industry. These hard coatings increase the lifetime of cutting tools by improving their wear resistance and allow higher cutting speeds. One of the primary drawbacks of these hard coatings is their brittle nature, which occasionally results in premature failure. This thesis investigated a solution ...
Dynamic modeling of spindle-tool assemblies in machining centers
Ertürk, Alper; Özgüven, Hasan Nevzat; Department of Mechanical Engineering (2006)
Regenerative chatter is a well-known machining problem that results in unstable cutting process, poor surface quality, reduced material removal rate and damage on the machine tool itself. Stability lobe diagrams supply stable depth of cut ا spindle speed combinations and they can be used to avoid chatter. The main requirement for generating the stability lobe diagrams is the system dynamics information at the tool tip in the form of point frequency response function (FRF). In this work, an analytical model ...
Citation Formats
H. Cesur, “Development of cubic boron nitride (cbn) coating process for cutting tools,” M.S. - Master of Science, Middle East Technical University, 2009.