Sıtkı Akincioğlu - Academia.edu (original) (raw)

Papers by Sıtkı Akincioğlu

Journal of Material Sciences & Engineering, Jul 13, 2017

Uluslararası Teknolojik Bilimler Dergisi, Mar 1, 2012

Bu çalışmada, AISI D2 soğuk iş takım çeliğinin delinmesinde, M35 HSS matkaplara uygulanan derin k... more Bu çalışmada, AISI D2 soğuk iş takım çeliğinin delinmesinde, M35 HSS matkaplara uygulanan derin kriyojenik işlemin (-196 ºC) takım ömrü, takım aşınması, mikro yapı ve mikro sertlik üzerine etkileri araştırılmıştır. Delme deneyleri üç farklı kesme hızı (20, 25 ve 30 m/dak), sabit ilerleme (0,1 mm/dev) ve delme derinliğinde (7 mm) gerçekleştirilmiştir. Kesici takımlara uygulanan derin kriyojenik işlemin, kalıntı östeniti martenzite dönüştürmede ve daha homojen karbür dağılımı sağlamada önemli bir etkiye sahip olduğunu mikro yapı fotoğrafları ve mikro sertlik değerleri göstermiştir. Kriyojenik işlem uygulanan takımlar takım aşınması ve takım ömrü bakımından konvansiyonel işlem uygulanan takımlara göre daha iyi sonuçlar vermiştir. Takım ömrü deneyleri, kriyojenik işlem uygulanmış takımlarla % 33-62 oranında ömür artışı elde edildiğini göstermiştir. Takımlarda genel olarak yığıntı talaş (BUE) oluşumu, dış köşe kenar ve yanak aşınmasının etkin olduğu belirlenmiştir. Genel olarak kriyojenik işlemin takım aşınması ve takım ömrü üzerinde olumlu etkilere sahip olduğu görülmüştür.

Journal of Aeronautics and Aerospace Engineering, Oct 26, 2017

Aircraft Engineering and Aerospace Technology, Jun 4, 2021

Purpose The purpose of this study was to optimize the surface roughness (Ra), delamination damage... more Purpose The purpose of this study was to optimize the surface roughness (Ra), delamination damage at the hole entrance (FdT) and at the hole exit (FdB) and kerf angle (K) in the drilling of aramid fiber-reinforced polymer (AFRP) composite material using abrasive water jet (AWJ) machining. Design/methodology/approach The AFRP composite was produced by the vacuum infusion method. The drilling experiments were performed on an AWJ machine using a three-axis computerized numerical control system. Machine processing parameters were determined as water pressure (2,000, 3,000 and 4,000 bar), stand-off distance (2, 4 and 6 mm) and traverse feed rate (150, 250 and 350 mm/min). Optimization of processing parameters in the drilling experiments was carried out according to the Taguchi L27 (33) orthogonal array. In addition, gray relational analysis (GRA) was used to analyze the complex uncertainty affecting the results. Findings Results of the drilling operations demonstrated that water pressure (P) was the most effective parameter, with 65.3%, 65.2%, 49.8% and 52.1% contribution rates for Ra, FdT, FdB and K, respectively. Practical implications Reliable results have been obtained with Taguchi-based GRA while drilling AFRP composite material using AWJ. Significant results have been achieved to increase the hole quality in the drilling of AFRP composite material. Originality/value The new approach is to present more detailed analysis by using Taguchi method and multi-decision Taguchi-based gray relation analysis in AFRP composite material drilling using AWJ. Thus, time and experiment costs are saved.

Journal of Materials Engineering and Performance, Mar 9, 2021

This study investigated the effect of deep cryogenic treatment (−140 °C) on the wear resistance, ... more This study investigated the effect of deep cryogenic treatment (−140 °C) on the wear resistance, hardness, wear rate and electrical conductivity of X153CrMoV12 steel. The results showed that with deep cryogenic treatment, the friction coefficient was increased by 64.67% compared to that of traditional heat treatment. In addition, it was observed that fine carbide was formed, the carbide rate increased, and the particles were homogeneously dispersed by the deep cryogenic treatment. The difference in the wear rate of deep cryogenic treatment 2 (Cry-2) and deep cryogenic treatment 1 (Cry-1) sample was 33.6 and 29.6% higher than that of the conventional heat treatment (CHT) sample, respectively. The microhardness value of Cry-2 and Cry-1 sample was 9.9 and 8.3% higher than that of the CHT sample, respectively. With Cry-2, the wear rate was reduced by 50.7% compared to CHT samples.

Facta Universitatis, Series: Mechanical Engineering

Electrical discharge machining (EDM) provides many advantages for the shaping of metallic materia... more Electrical discharge machining (EDM) provides many advantages for the shaping of metallic materials. It also provides better surface quality for Ti alloys used in the defense industry. In this study, experiments were carried out with different EDM parameters using the Titanium (Gr2) alloy. A number of novel industrial processes have been developed as a result of advances in technology. For a product to be developed, these novel approaches must be utilized to determine optimum parameters. The Taguchi method was applied in the experiments with EDM. The impact the test parameters had on the performance characteristics of tool wear rate, material removal rate, depth, and surface roughness were analyzed by the variance analysis (ANOVA). Quadratic regression analyses were carried out to reveal the correlation between the experimental results and the predicted values. According to the ANOVA results for material removal rate (MRR), tool wear rate (TWR), depth, and surface roughness, the mo...

Aircraft Engineering and Aerospace Technology

Journal of Materials Engineering and Performance

Sixth International Conference on Advances in Applied Science and Environmental Technology - ASET 2017, 2017

Easy to supply and cheap materials like agricultural wastes are now appearing as a candidate mate... more Easy to supply and cheap materials like agricultural wastes are now appearing as a candidate materials in the brake pads development with commercial production and environmental consideration. In this study, asbestos-free automotive brake pads produced from walnut shell dusts (WAS) and wollastonite (WOS) with phenolic-resin binder was evaluated. Two nonasbestos friction material samples containing walnut shell dusts and wollastonite jute fibers from biomass as biodegradable components were prepared, also including several from natural resources, such as, basalt fibers, zircon, barite, and vermiculite. The physical, mechanical properties of the brake pad were studied.

Polymer-plastics technology and materials, Mar 7, 2022

Proceedings Of The Institution Of Mechanical Engineers, Part E: Journal Of Process Mechanical Engineering, May 25, 2022

In recent years, cryogenic treatment has been applied to improve the performance of cutting tools... more In recent years, cryogenic treatment has been applied to improve the performance of cutting tools. Improving the performance of cutting tools can improve the surface qualities of workpiece and reduce costs. Nickel-based superalloys are difficult to machine. It is necessary to improve the machinability properties of these hard-to-machine alloys and to increase the product quality. In this study, the effects of cryogenically treated physical vapor deposition-coated tools on the turning performance of nickel-based Hastelloy C22 superalloy were investigated. Deep cryogenic treatment (−145°C) and shallow cryogenic treatment (−80°C) were applied to the physical vapor deposition-coated tools. Experiments were carried out under dry conditions. The cutting parameters selected for the machining were cryogenically treated cutting tools, cutting speed, and feed rate. The deep cryogenic treatment had a favorable influence on the performance of the physical vapor deposition-coated carbide inserts. Thanks to the deep cryogenic treatment applied to the cutting tools, 99.5% and 19.7% improvement in surface roughness and cutting forces were achieved, respectively, compared to the untreated tool. The deep cryogenic treatment contributed more to the wear resistance of the tools than the shallow cryogenic treatment. A slight increase in the hardness and electrical conductivity of the tools was detected thanks to the cryogenic treatment.

The International Journal of Advanced Manufacturing Technology, Jun 11, 2015

Polymer-Plastics Technology and Materials

Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering

Gazi Journal of Engineering Sciences, 2018

Son yıllarda otomotiv teknolojisinin gelişmesiyle birlikte, fren balatası için alternatif kompozi... more Son yıllarda otomotiv teknolojisinin gelişmesiyle birlikte, fren balatası için alternatif kompozisyon arayışı da artmıştır. Kompozisyonunda birçok tozu barındıran fren balatalarının, performansının yanında, alternatif tozlardan üretilmesi de beklenmektedir. Alternatif tozlarda, çevre dostu olması ve maliyetinin düşük olması istenen en önemli faktörlerdendir. Bu çalışmada, ülkemizde yüksek rezerve sahip boraks ve wollastonite kullanılmıştır. Alternatif tozlarla üretilen fren balatası numunelerinin su ve yağ emme davranışları test edilmiştir. Elde edilen sonuçlar referans olarak kullanılan ticari fren balataları ile kıyaslanmıştır. Suda bekletilen numunelerin sertlik değerleri, yağda bekletilen numunelere göre daha fazla düşmüştür. Katkı maddesi olarak wollastonite kullanılan numunelerde daha az sertlik değişimi gözlenmiştir. Boraks katkılı fren balatalarının yoğunluk değerleri referans fren balatasına daha yakın değerlerdedir. Wollastonite katkılı fren balatalarında gözlemlenen ağırlık değişimi ise ticari fren balatası numunesine yakın değerlerde elde edilmiştir.

Polymer Composites, 2021

In this study, an eco‐friendly brake composite sample (EFP) was produced with 3.5% hazelnut shell... more In this study, an eco‐friendly brake composite sample (EFP) was produced with 3.5% hazelnut shell dust as a natural additive material. Friction tests were performed on the manufactured pad sample and on a commercial pad (CP) using both a Chase‐type test machine and a specially designed device. A different approach is presented with the evaluation of the two different test device results. The experimental results were compared using the Taguchi method and it was concluded that the braking performance of the sample with hazelnut shell dust was in accordance with international standards. As a result of the study; the nominal friction coefficient value was found to be 0.505 μ. The shearing force of the EFP and CP samples was measured at 607.3 and 850.5 N, respectively. The friction coefficient values obtained from the EFP and CP samples were in accordance with the SAE J‐661 standard and are in the “F” letter class.

Plastics, Rubber and Composites, 2021

ABSTRACT In the production of brake pad composites, a well-designed new composition formulation p... more ABSTRACT In the production of brake pad composites, a well-designed new composition formulation plays a key role in improving performance. The purpose of this study; was to investigate the effectiveness of a specifically developed formulation under brake-test conditions. The composition of the brake lining consists of 18 powder materials. As the friction adjuster, Petro-coke powder was used instead of Cashew, which is cheaper and more readily available. The wear tests were carried out in a special design test device simulated close to the real environment. The results obtained have been compared with commercial brake pads. The friction coefficient values decrease with increasing disc temperatures. Brake tests showed that as a friction modifier, petro-coke provided a more effective stabilizer for the friction coefficient and improved the specific wear rate. Also the study can be utilized effectively in determining the friction coefficient and the specific wear rate of designed brake composites.