Mustafa Sabri Gök

Application of Taguchi Method to Study Abrasive Wear Behavior of Ceramic-Coated Specimens with Plasma Technique.

Different types of ceramic powders were coated on the surface of middle carbon steel using a plasma method. Coated surfaces were tested experimentally with regard to their abrasive wear resistance. To evaluate test data obtained, an experimental design method, which is based on the Taguchi method, was used. By using the Taguchi method, influence of test parameters, such as normal load, abrasive grit size, and material on wear resistance of coatings by calculating signal-to-noise (S/N) ratio and analysis of variance (ANOVA), could be estimated. From analysis of test results, it was determined that load factor has the most effect on wear of coating.

A Comparative Study of the Microabrasion Wear Behavior of CoNiCrAlY Coatings Fabricated by APS, HVOF, and CGDS Techniques

The current study focuses on the microabrasion wear and microstructural properties of CoNiCrAlY coatings fabricated on nickel-based superalloy substrates using atmospheric plasma spraying (APS), high-velocity oxygen fuel (HVOF), and cold gas dynamic spraying (CGDS) methods. The microabrasion tests were performed on the samples for different durations in order to understand the wear mechanism of thermally sprayed coatings and influence of the coating microstructure on the wear mechanism. The microstructures of as-sprayed coatings and wear mechanisms on the worn coatings were investigated. Initial surface topography was examined using a surface profilometer. Coating hardness measurements were performed with a microhardness tester. The lateral fracture was observed as the wear mechanism on the samples. The wear resistance of the coatings has changed with the surface features of the samples depending on the coating production process.

Effect of Boron Nitride Coating on Wear Behavior of Carbide Cutting Tools in Milling of Inconel 718

Boron nitride based tribological coatings promise hope in tribological applications thanks to their excellent lubrication and heat resistance properties. However, the applicability of these coatings on cutting tools in machining applications is not well known and it needs to be revealed. Therefore, in this study, a boron nitride (BN) coating was deposited on carbide milling tools. Inconel 718 was used as workpiece material in face milling tests to determine the wear behavior of the BN coated carbide tools. Surface roughness and tool wear was recorded in relation with cutting length. Wear mechanisms on the coated carbide tools were determined using scanning electron microscopy in combination with energy dispersive spectroscopy. Abrasive and adhesive wear was found as main failure mechanisms on the worn tools. Approximately two times longer tool life was obtained with the BN coated carbide tools.