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Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this experimental study is to establish the optimum heat treatment procedure and machining parameters to obtain values of cutting force and surface roughness in machining AISI 1050 workpiece by utilizing grey relations analysis based on Taguchi method. In this regard, machining operations were carried out at three different cutting speeds and three different feed rates at a constant depth of cut. Taguchi mixed-level design L18 (2^2 3^2) was chosen for machining experiments. The optimum heat treatment and machining parameters for determination of cutting force and surface roughness values were identified according to the fact that higher the Signal/Noise ratio is better based on grey relations analysis of Taguchi method. The results showed that the optimum parameters for surface roughness and cutting forces were obtained as 0.1 mm/rev at feed rate and 180 m/min at cutting speed with cryo-treated cutting tool. According to ANOVA table and Signal/Noise ratios, it was specified that the most effective parameters on cutting forces and surface roughness were feed rate, cutting speed and heat treatment conditions, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Dicle University Journal of Engineering / Dicle Üniversitesi Mühendislik Dergisi is the property of Dicle Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, two distinc cutting tools, coated carbide and cermet, were used in turning 20NiCrMo2 case-hardened steel. Turning experiments were carried out with these tools at three distinc cooling methods (dry, MQL, nano-MQL), three distinc cutting speeds (80, 120, 160 m/min) and three distinc feed rates (0.125, 0.167,0.2 mm/rev) has been carried out. As a result of the experiments, the effects of cutting parameters, cutting tool type and cooling method type on the average surface roughness (Ra) and cutting zone temperature (Ctemp) were examined. In the study, the Taguchi optimization method was also applied to the experimental Ra and Ctemp results. As a result of Taguchi optimization, the most effective cutting parameters on Ra and Ctemp were determined. This result was confirmed by ANOVA analysis. Optimum parameters for Ra; cermet cutting tool, nano-MQL cooling method, 160 m/min cutting speed and 0.12 mm/rev feed rate. Optimum parameters for Ctemp; carbide cutting tool, nano-MQL cooling method, 80 m/min cutting speed and 0.12 mm/rev feed rate. Ideal numbers for both Ra and Ctemp were not found in the 18 turning experiments performed. Therefore, the 19th experiment was conducted for both output parameters. The average surface roughness value for optimum parameters was measured as 1.08 pm. [ABSTRACT FROM AUTHOR]

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Current Research in Dental Sciences is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Necmettin Erbakan University Dental Journal (NEU Dent J) is the property of Necmettin Erbakan University Dental Journal (NEU Dent J) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Selcuk Dental Journal is the property of Selcuk Dental Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Geleneksel soğutma yöntemlerinin gerek insan sağlığına gerekse çevreye vermiş olduğu zararlardan dolayı kullanımı son yıllarda oldukça azalmıştır. Bu soğutma yönteminin yerine daha çevreci, ekonomik ve geleneksel soğutma yöntemlerine göre insan sağlığı açısında olumsuzluk yaratmayacak olan soğutma yöntemi kullanılmaya başlanmıştır. Bu çalışmada AISI 1050 çeliği üç farklı kesme hızı (340, 400 ve 460 m/dak) ve iki farklı ilerleme miktarında (0,2 ve 0,3 mm/dev) tornalanmasında kesme şartlarının etkisi araştırılmıştır. Deneyler kuru kesme koşulunda ve 90, 150 ve 200 ml/saat minimum miktarda yağlama (MMY) akış hızında gerçekleştirilmiştir. Deneyler sonrasında kesme parametrelerinin ve kesme şartlarının ortalama yüzey pürüzlüğü ve kesme kuvvetleri üzerindeki etkileri incelenmiştir. Elde edilen değerler doğrultusunda minimum miktarda yağlama uygulamasının ve akış hızı artışının kesme kuvvetlerini ve ortalama yüzey pürüzlüğü değerlerini olumlu yönde etkilediği sonucuna ulaşılmıştır. En düşük ortalama yüzey pürüzlüğü değeri 1,42 µm olarak elde edilmiştir. En düşük kesme kuvveti ise 1084 N olarak ölçülmüştür.

Vanadis 4E is a versatile powder metallurgical tool steel widely used in today's market with high wear resistance and excellent yield properties. Drilling operations applied to materials are one of the operations commonly used in the machining industry. In drilling operations, coated or uncoated drills are used, which may vary according to the material used. This study applied drilling operation to Vanadis 4E powder metallurgical steel with TiN-coated HSS drills. In the study, Drills with diameters of 5, 8.5, and 10.5 mm, cutting speeds of 22, 23, and 24 m/min, and feed rates of 0.10, 0.12, and 0.14 mm/tooth was used. Nine experiments were carried out using the Taguchi L9 orthogonal array. After the experiments, the material was cut from the holes, and the roughness values were measured from the inner surfaces of the holes. In addition, hardness measurements were made from the material surfaces around the holes. The wear conditions of the drills used in the experiments were examined with an optical microscope after the experiment. The formations after each experiment were also examined. The best roughness value was obtained with the 5 mm diameter drill in the 1st experiment, the best roughness value was obtained in the experiments carried out with the 8.5 mm diameter drill in the 6th experiment, and the best roughness value was obtained in the 7th experiment for the 10.5 mm diameter drill. When the wear in the drills was evaluated, it was observed that the side surface and radial wear occurred.

Copyright of Current Research in Dental Sciences is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Increasing supply chain problems in recent years have a negative impact on costs in many areas. Due to the global crisis, raw material prices increased and the manufacturing sector was seriously affected. Production planning and material saving should be done correctly in order to minimize the losses in the manufacturing sector. The most efficient way to reduce production costs is to use suitable cutting tools and choose the right machining parameters. In this study, the drilling of AISI D2 steel, which is widely used in the mold industry, was examined and optimum machining parameters were determined. TiN coated drills are used for drilling operations. The effects of machining parameters on Surface Roughness (Ra) and Thrust Force (Fz) were Sinvestigated by Taguchi and ANOVA. Surface roughness and thrust force values during drilling were measured. Thrust force values were also analyzed numerically by the Finite Element (FE) method. Ra and Fz were also low at low feed rate and low cutting speeds. While the feed rate affected Ra the most, the Fz affected the cutting speed the most. The lowest Ra and Fz were at 30 mm/min feed rate and 25 m/min cutting speed. According to the ANOVA, it was determined that the machining parameters were effective on both Ra and Fz. R² values for Ra and Fz are calculated over 95%. [ABSTRACT FROM AUTHOR]

In this study, we performed experimental and statistical analysis on the cutting of AISI 304 stainless steel using a commonly utilized laser cutting machine. Three different gas pressures (5.1, 6.4 and 8 bar), three different cutting speeds (2048, 2560 and 3200 mm/min), fixed focal point (-4 mm), fixed frequency (5000 Hz) and fixed gas (Nitrogen) were used as cutting parameters. As a result of the study, it was observed that the surface roughness decreased as the cutting speed increased at all pressure values, and the surface roughness increased as the pressure increased at all cutting speed values. It was determined that the top and bottom kerf width decreased with increasing cutting speed and decreasing gas pressure, and the top and bottom kerf width increased with increasing gas pressure and decreasing cutting speed. When the signal/noise ratios were analyzed as a result of Taguchi analysis, the optimum cutting parameter was calculated as Level 1 (5.1 bar) for pressure and Level 3 (3200 mm/min) for cutting speed. When the variance results were analyzed, it was determined that the important parameter affecting the surface roughness from the pressure and cutting speed factors was determined as cutting speed with 70.74%. [ABSTRACT FROM AUTHOR]

Aluminium alloys are widely used in various manufacturing industries due to their unique light weight performance, high strength-to-weight ratio, and high corrosion resistance, Therefore, aluminium alloys should be well studied during machining, and examined how to obtain a wellmachined surface and increase processing precision. In this study, the effects of cutting parameters (cutting speed, feed rate, peripheral depth of cut, and tool holder type) on surface roughness and processing precision in CNC milling of Al 7075-T6 alloy were investigated using the Taguchi L27 method. In addition, variance analysis (ANOVA) was performed to find the effect ratios of cutting parameters on surface roughness and processing precision. As a result, it was observed that the largest effect ratio of the peripheral depth of cut on surface roughness and processing precision was 37.7 % and 36.1 %, respectively. The used tool holders did not have any effect on the surface roughness of the work-piece. However, a tool holder type has played a significant role in processing precision. The hydraulic tool holder has provided maximum processing precision, while the mechanical tool holder has showed a minimum precision level of the machining work-pieces. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Amaç: Bu çalışmanın amacı, üç farklı tek renkli rezin kompozitin yüzey sertliği, yüzey pürüzlülüğü, su emilimi ve suda çözünürlük özelliklerini karşılaştırmaktır. Gereç ve Yöntemler: Supra-nano dolduruculu kompozit (Omnichroma (OC), Tokuyama Dental, Japonya), mikrohibrit dolduruculu kompozit (Essentia(ES),GC,Japonya) ve ultrafine nanohibrit dolduruculu kompozitten (Charisma Topaz ONE(CTO),Kulzer,Almanya) hazırlanan toplam 90 adet örnekten, 30’ar örnek içeren 3 grup oluşturuldu. Kompozit örnekleri 5 mm çapında 2 mm kalınlığında teflon kalıplar kullanılarak hazırlandı. Hazırlanan örneklere alüminyum oksit cila diskleri (Sof-Lex disk, 3M Espe, ABD) ile polisaj yapıldı. Kompozit örneklerin Vickers sertlik değerleri (n=10) (VHN, Shimadzu, Kyoto, Japonya) ve yüzey pürüzlülük değerleri (Ra) (n=10) profilometre cihazı (MarSurf M 300 C, Mahr, Almanya) kullanılarak ölçüldü. Su emilimi ve suda çözünürlük değerleri (n=10) ISO standartlarına (ISO 4049:2009) göre hesaplandı. Verilerin istatistiksel analizi tek yönlü ANOVA ve Duncan testleri kullanılarak değerlendirildi (p

The use of fiber reinforced composite materials (FRP) has increased in many areas. These materials need to be processed with some machining methods according to their usage areas, but their machinability is difficult. In this study, surface roughness (SR), delamination factor (Fd) and thrust forces were investigated in the drilling of glass fiber reinforced composite material (GFRP) produced by pultrusion with a coated and uncoated drill. Microstructures of chips formed during drilling were investigated and their effects on surface roughness were determined. Three different cutting speeds (60, 70, 80 m/min) and feed rates (0.06, 0.09, 0.12 mm/min) were selected as machining parameters. At the end of the study, it was found that feed rate had a more significant effect on surface roughness, delamination factor and thrust force. It was observed that as the cutting speed increased, the surface roughness, thrust force and delamination factor decreased. The lowest thrust force and Fd occurred at a cutting speed of 80 m/min and a feed rate of 0.06 mm/min. However, the lowest SR was obtained at a cutting speed of 70 m/min and a feed rate of 0.06 mm/min.Better results were obtained with TiN coated drills compared to uncoated drills. [ABSTRACT FROM AUTHOR]

Machine tools are required to be able to produce workpieces according to the desired technical requirements. The goal of machining is to achieve a high production volume of good quality with maximum tool life, short production time, and low cost. The surface properties obtained as a result of the changing and developing technology in cutting processes, the introduction to manufacturing, and especially the post-processing processes are of great importance. While the time obtained as a result of fast cuts has economic value, high-quality surface obtaining provides cost savings by minimizing the subsequent machining operations. Within the scope of the study, Ø120 mm ST-52 and Ø120 mm AISI 4140 materials have been cut with smart and automatic cutting modes by our domestic band saw machine. As a result of the cuts, the roughness values and curvatures of the samples have been checked with the surface roughness device and surface gauge. While the surface roughness after cutting was 4.45 µm with the automatic cutting mode, this value decreased by 16% to 3.71 µm with the smart cutting mode. [ABSTRACT FROM AUTHOR]

Copyright of Meandros Medical & Dental Journal is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Duzce University Journal of Science & Technology is the property of Duzce University Journal of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Selcuk Dental Journal is the property of Selcuk Dental Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Current Research in Dental Sciences is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Advanced Research in Health Sciences (JARHS) / Sağlık Bilimlerinde İleri Araştırmalar Dergisi (SABİAD) is the property of Journal of Advanced Research in Health Sciences (JARHS) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the surfaces of AISI 1050 Medium Carbon Steel and D2 Cold Work Tool Steel, which are commonly used in the machine manufacturing industry, were processed using the burnishing method. In the burnishing experiments, cylindrical materials with dimensions of Ø50x30mm and a Ø20mm hole drilled in the center were used. For the turning process, the cutting speed was selected as 60 m/min and the feed rate as 0.25 mm/rev. The burnishing process was applied in a single pass. The properties such as microhardness, surface morphology, circularity, cylindricality and surface roughness of the materials by the burnishing process were examined in detail. After burnishing, the hardness of AISI 1050 and D2 cold work tool steel materials was measured to be 292 HV and 302 HV, respectively. The results obtained showed that the burnishing process increased the hardness value of AISI 1050 steel proportionally more than the hardness value of D2 steel. It was determined that the circularity and cylindrical properties of the hole surfaces were improved. The obtained results show that the burnishing process will increase the efficiency of the machine elements working in contact and the damage that may occur during the operation of these machine elements can be minimized by burnishing process. [ABSTRACT FROM AUTHOR]

“İkincil dönel eksenli taşlama yöntemi (GMASRA)”, son yıllarda düzlem yüzey taşlama işleminde kullanılmaya başlanan yenilikçi bir yöntemdir. Klasik taşlama yönteminin aksine GMASRA yönteminde aynı anda iki farklı eksende taşın dönme hareketi mevcuttur. Birinci dönme hareketi, klasik taşlama yöntemindeki taşın çevresel dönme hareketidir. İkinci dönme hareketi ise yeni eklenen ikinci dönme hareketi olan taşın eksenine dik yönde bir eksen etrafında dönme hareketidir. GMASRA yönteminde, klasik taşlama yöntemine göre, hem yüzey pürüzlülüğünde daha küçük değerler elde edilmekte hem de birbirine yakın yüzey pürüzlülüğü değerleri her yönde elde edilebilmektedir. Bu yöntemde işleme parametrelerinin yüzey pürüzlülüğü üzerine etkisinin ve işlem parametreleri ile ilişkisinin analiz edilmesi önemlidir. Bu çalışma da bu amaca yönelik yüzey yanıt yöntemi ile farklı modeller geliştirilmiş ve yüzey pürüzlülüğü üzerine işlem parametrelerinin etkisi analiz edilmiştir. İşlem parametreleri olarak üç farklı taş cinsi (NK36P5V, NK46O5V, NK60N5V), üç farklı talaş derinliği (0,01, 0,02 ve 0,03 mm), üç farklı fener mili devri (80, 160, 240 dev/dak), 2 farklı yanal kayma miktarı (4, 8 mm) seçilmiş ve taşlama işlemi sonucu yüzey pürüzlülükleri ölçülmüştür. Sonuçta, problemin çözümü için oluşturulan altı yüzey yanıt modelin başarı ile kullanılabileceği ve tutarlı sonuçlar üretebileceği görülmüş, yüzey pürüzlülüğü üzerinde en büyük etkinin fener mili devri ve talaş derinliği olduğu tespit edilmiştir. Yüzey pürüzlülük değerlerinde, fener mili devrinin artması ile azalma, talaş derinliğinin artması ile artma gözlenmiştir. Artan yanal kayma miktarlarında bu etkinin yönünün talaş derinliğine doğru evrildiği de ayrıca görülmüştür.

Bu çalışmada alüminyum matrisli kompozitlere takviye edilen seramik parçacık boyutunun işlenebilirliğe etkisi incelenmiştir. Bu amaçla ilk etapta üç farklı boyuttaki MgO parçacıkları, %10 ağırlık oranında sıvı Al 2024 içerisine takviye edilerek karıştırmalı döküm yöntemiyle kompozit malzemeler üretilmiştir. Daha sonra üretilen kompozitler üzerinde tornalama yöntemiyle, iki farklı kesici takım kullanılarak işlenebilirlik deneyleri yapılmıştır. Deneylerde 63, 94, 133 ve 196 m/min kesme hızları, 0,03 mm/rev ilerleme değeri ve 1 mm sabit kesme derinliği uygulanmıştır. İşlenen yüzeylerin pürüzlülük ölçümleri yapılmış, çıkan talaş şekillerine bakılmış ve kullanılan kesici takımların aşınma davranışları incelenmiştir. Sonuç olarak alüminyum matris içerisindeki MgO takviye parçacık boyutunun ve farklı kesici takımların, yüzey pürüzlülüğü, talaş şekli ve takım aşınmaları üzerinde çok önemli etkisi olmadığı görülmüştür. Yüzey pürüzlülüğünde en önemli etkiyi kesme hızındaki değişimler yapmıştır. Aynı şekilde kesme hızındaki değişimler, talaş şekilleri ve kesici takım aşınma davranışlarında da en etkili parametre olmuştur.

Amaç: Çalışmanın amacı; farklı protez temizleme ajanlarının, total protezlerin diş eti modifikasyonunda kullanılan indirekt kompozit rezinler ve ısı ile polimerize olan akrilik kaide materyalinin yüzey pürüzlülüğüne etkisini değerlendirmektir. Gereç ve Yöntemler: Çalışmada iki farklı indirekt diş eti kompoziti (Gradia Plus Gum ve SR Nexco Paste Gingiva) ve bir adet ısı ile polimerize olan polimetil metakrilat akrilik rezin (PMMA) (Meliodent) test edildi. Her materyalden 30 adet olmak üzere çapı 10 mm, yüksekliği 2 mm olan disk şeklinde toplam 90 adet örnek hazırlandı. Örnekler temizleme solüsyonlarına göre 3 alt gruba ayrılarak (n = 10) distile su (kontrol) ve iki farklı protez temizleme solüsyonunda (% 1’lik NaOCl ve Corega) 90 günlük kullanım süresine eşit olacak şekilde bekletildi. Örneklerin başlangıç (Ra0) ve 90 gün sonra (Ra1) yüzey pürüzlülüğü ölçümleri profilometre ile yapıldı. Elde edilen veriler Kruskal-Wallis ve Mann-Whitney U testleri kullanılarak analiz edildi. Wilcoxon Signed Rank testi her materyalin Ra0 ve Ra1 değerlerini kıyaslamada kullanıldı (p < 0.05). Bulgular: Farklı protez temizleme solüsyonlarının, materyallerin yüzey pürüzlülük değerlerine etkisi istatistiksel olarak anlamlıydı (p < 0.001). Tüm materyaller için, Ra0 ve Ra1 değerleri arasındaki farklılık % 1’lik NaOCl’de istatistiksel olarak anlamlı iken (p < 0.05) Corega için istatistiksel bir fark gözlenmedi. % 1’lik NaOCl PMMA’nın yüzey pürüzlülüğünde istatistiksel olarak anlamlı azalmaya sebep olurken, kompozit materyallerinde artışa sebep olmuştur. Sonuç: % 1’lik NaOCl protez temizleme solüsyonu, PMMA akrilik rezinlerin kimyasal temizliği için önerilebilir ancak kompozit rezinlerle modifiye edilen total protezlerde yüzey pürüzlülüğünü arttırdığı dikkate alınmalıdır. Alkalen peroksit içerikli Corega efervesan tabletin ise test edilen tüm materyaller için uygun bir temizleme solüsyonu olduğu söylenebilir.

Bu çalışmada, kuru frezeleme koşullarında üç farklı takım geometrisine sahip CVD TiAlN/Al2O3/TiCN kaplı karbür uçlar kullanılarak AISI 316L’nin yüzey bütünlük özelliklerini değerlendirmek için Taguchi yöntemi uygulanmıştır. Bir CNC tornada ortogonal dizili bir deneysel tasarım olan L18 (2x3x3x3) kullanılarak çeşitli deneyler yapılmıştır. İşleme parametrelerinin ortalama yüzey pürüzlülüğü, çevresel ve eksenel yüzey kalıntı gerilmeleri ve işleme sertleşmesi derecesi üzerindeki etkilerini belirlemek için varyans analizi (ANOVA) kullanıldı. İşleme parametreleri olarak kesme derinliği, kesici takım geometrisi, kesme hızı ve ilerleme hızı seçilmiştir. İşleme parametrelerinin kalite özellikleri üzerinde farklı etkileri olduğu görülmüştür. Kesme derinliği, yüzey pürüzlülüğü üzerinde nispeten etkili bir parametreydi ve diğer kalite özellikleri üzerinde önemli bir etkisi yoktu. Takım geometrisi ortalama yüzey pürüzlülüğünü etkilemedi. Ancak sırasıyla sertleşme derecesi, çevresel ve eksenel yüzey kalıntı gerilmeleri üzerinde daha etkili olmuştur. Kesme hızının sırasıyla eksenel ve çevresel yüzey kalıntı gerilmeleri ve sertleşme derecesi üzerinde daha önemli bir etkiye sahip olduğu belirlendi. İlerleme hızı, yüzey pürüzlülüğü üzerinde çok yüksek bir etkiye sahipken, sırasıyla çevresel ve eksenel yüzey kalıntı gerilmeleri ve sertleşme derecesi üzerinde de önemli bir etkiye sahip olduğu görülmüştür.

Copyright of Current Research in Dental Sciences is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Metal esaslı eklemeli imalat, bir enerji kaynağı ile metalik tozun veya telin katman katman eritilmesi yoluyla üç boyutlu (3B) nesnelerin imal edildiği modern bir üretim sürecidir. Seçici lazer eritme (SLM) yöntemi, karmaşık ve hafif yapıların üretimine olanak sağladığından hem bilimsel hem de endüstriyel alanlarda kullanılmaktadır. AlSi10Mg alaşımı havacılık, otomotiv, denizcilik ve medikal endüstrilerin yanı sıra, özel tasarımlara ihtiyaç duyulan çeşitli uygulamalarda yaygın olarak kullanılmakta ve SLM araştırmalarında öne çıkan malzemelerden biri durumundadır. SLM yöntemi ile üretilen bir ürünün kalitesi, ergitme için gerekli olan enerji yoğunluğunu etkileyen imalat parametrelerinin (lazer gücü, tarama hızı, tarama mesafesi, katman kalınlığı) optimizasyonunu gerektirmektedir. Uygun olmayan imalat parametrelerinin kullanılması ile süreç gereği deformasyon mekanizmalarından kaynaklanan iç gerilmeler oluşmakta ve parça üzerinde çarpılma, çatlama ve boyutsal değişim meydana gelmektedir. Toz malzeme özellikleri, toz tabakasının düzgün olmayan dağıtımı, imalat sırasında deformasyon, lazer ışınındaki değişiklikler gibi değişkenler metalurjik gözeneklere neden olabilmektedir. İmalat sürecinde oluşan her türlü kusur nihai parçanın mekanik özellikleri ve yüzey kalitesi üzerinde olumsuz etkiye sahiptir. Bu çalışmada seçici lazer ergitme yöntemi ile AlSi10Mg alaşımından yüksek yoğunlukta, yüksek mukavemet özelliklerinde ve yüksek yüzey kalitesinde parçalar üretmek için literatürde yapılan çalışmalar araştırılarak elde edilen sonuçlar sunulmuştur. Araştırma sonucunda, enerji yoğunluğunun ürün kalitesi üzerinde daha belirleyici olduğu tespit edilmiştir. Ürünlerde en az gözeneklilik için ideal enerji yoğunluğunun 50-75 J/mm3 aralığında olduğu, eklemeli imalat ile üretilen AlSi10Mg alaşımlı parçaların döküm yöntemi ile üretilenlere kıyasla daha iyi mukavemet özelliği gösterdiği belirlenmiştir.

Bu çalışmada, farklı oranlarda (%0,02; 0,1 ve 1) stronsiyum (Sr) içeren üç adet Al-12Si-Sr alaşımı kokil kalıba döküm yöntemiyle üretildi. Üretilen alaşımların içyapıları metalografik yöntemlerle, sertlik ve çekme dayanımı değerleri ise sırasıyla Brinell ölçüm yöntemi ve çekme deneyi ile belirlendi. Farklı Sr oranları ve kesme parametrelerinin bu alaşımların tornalanması esnasındaki kesme kuvveti ve yüzey pürüzlülüğü üzerindeki etkileri, farklı kesme hızı (200, 300 ve 400 m/dak), ilerleme (0,05; 0,1 ve 0,15 mm/dev) ve sabit kesme derinliği (1,5 mm) koşullarında CVD-TiCN/Al2O3/TiN kaplamalı karbür kesici uç kullanılarak tespit edilmiştir. Metalografik incelemeler, Al-12Si-0,02Sr alaşımının içyapısının α, ötektik alüminyum-silisyum, Al-Fe-Si (δ) fazları ile primer silisyum parçacıklarından, Al-12Si-0,1Sr alaşımının içyapısının ise Al-12Si-0,02Sr alaşımında gözlenen fazlara ilave olarak Al-Sr-Si fazından oluştuğunu göstermiştir. Bu incelemelerde ayrıca Sr oranı arttıkça Al-Sr-Si fazının büyüdüğü ve/veya bu faz parçacıklarının sayısının arttığı gözlenmiştir. Üretilen alaşımlar içerisinde en yüksek sertlik ve çekme dayanımı değeri Al-12Si-0,1Sr alaşımından elde edilmiştir. Alaşımların kopma uzaması değeri ise artan Sr oranı ile sürekli azalmıştır. İşleme testlerinde kesme hızının artması ile kesme kuvveti ve yüzey pürüzlülüğünün azaldığı, ilerlemenin artması durumunda ise bu değerlerin arttığı tespit edilmiştir. Tornalama testlerinde en düşük kesme kuvveti ve yüzey pürüzlülüğü değerleri, Al-12Si-0,1Sr alaşımının işlenmesinde ölçülürken, en yüksek değerler ise Al-12Si-0,02Sr alaşımında ölçülmüştür. Alaşımın işlenmesi esnasında yığıntı talaş (YT) oluşumu gözlenmiştir. YT oluşumunun yüksek kesme hızı ve düşük ilerleme kombinasyonları kullanılarak azaltılabileceği ortaya konulmuştur. Kesici uçta en az YT oluşumu, Al-12Si-0,1Sr alaşımında gözlenirken, en fazla YT oluşumu ise Al-12Si-0,02Sr alaşımında gözlenmiştir. İşleme deneylerinden elde edilen bulgular, alaşımların yapısal ve mekanik özelliklerine dayandırılarak irdelenmiştir.

This work DIN 41Cr4 tempered steel of hot forging applied focuses on the investigation of machinability of samples obtained by cooling in sand and air. The machinability evaluation has made in terms of main cutting force (Fc) and surface roughness (Ra). DIN 41Cr4 original material (OM), sand (SC) and air cooling (AC) samples has investigate microstructure and hardness changes. Turning experiments carried out at five different cutting speeds, four different feed rates and depth of cut. As a result, it has seen that the cooling environment of the samples after hot forging has a significant effect on the hardness and microstructure. The lowest main Fc was 131.54 N in the OM, while the highest Fc was 337.49 N in the AC sample in the turning of the samples. Evaluated in terms of Ra, the lowest Ra was obtained as 0.505 μm in the AC sample, while the highest Ra was obtained as OM 1.793 μm. It has been observed that the main Fc increases, while the Ra somewhat decreases depending on the increase in hardness and decrease in grain size. In general, SEM examinations, it has been seen that built-up edge (BUE) and breaks occurred in the cutting tools. [ABSTRACT FROM AUTHOR]

Copyright of Duzce University Journal of Science & Technology is the property of Duzce University Journal of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Duzce University Journal of Science & Technology is the property of Duzce University Journal of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the effect of machining parameters on the surface quality of the machining of different surfaces of the Oriental beech (Fagus orientalis Lipsky) tree species used in the woodworking and furniture industry was investigated and it was aimed to determine the optimum machining parameters. The experiments were carried out at two different dept of cut (depth of cut 3.33 mm or 2.5 mm per machining, total 10 mm dept of cut) by using two different 8 mm diameter cutters at 8000, 12000 and 16000 rpm at feed rates of 1000, 1500 and 2000 mm/min. Surface roughness measurements were made according to ISO 4287 by using a test device with the stylus method on the surfaces obtained in different sections. Ra and Rz roughness measurements were performed on the surfaces obtained as a result of machining. It has been observed that the machining parameters have an effect in different rates on the surface roughness and the results are evaluated by comparing with the literature. The lowest average roughness (Ra=5,18 µm) value was obtained in 3-layer processing, 1000 mm/min feed rate at 16000 rpm, cutter type 2 for measurements perpendicular to the fibers on floor surfaces. The lowest values (Ra=2,84 µm) on the side surfaces were obtained as 4-layer machining, 1000 mm/min feed rate at 16000 rpm, cutter type 1 for measurements perpendicular to the fibers.

In this experimental study on machinability, the effects of cutting depth and cutting tools of different profiles on the roughness of the machined surface were investigated in the turning of Al 6061 aluminum alloy. In the experiments, a constant feed rate of 0.2 mm/rev, two different cutting speeds of 125 m/min, 250 m/min and cutting depths of 0.4-0.8-1.6-2.4 mm were selected. The lowest roughness values were obtained as 0.5 µm at 250 m/min cutting speed with the SNMA coded cutting tool. As the depth of cut values decreased, the roughness of the surfaces decreased in general. However, the reverse behavior was observed in machining with SNMA tool and the highest roughness value was obtained at 0.4 mm depth of cut. When all cutting tools and cutting parameters are evaluated together, the highest roughness value was measured as 7.22 µm at 2.4 mm cutting depth with the tool coded TNMG. With the change of cutting speed, different surface roughness values were obtained according to the cutting tool type. However, the expected decrease in roughness values did not occur with increasing cutting speed. DCGT coded tool could not outperform other cutting tools in terms of surface roughness. As a result of this study, it has been determined that the machining performance of the SNMA series coated and negative rake tools is higher. [ABSTRACT FROM AUTHOR]

In this study, the machining characterization properties (namely, cutting power Pc, specific cutting energy ps and surface roughness Ra) of AISI 8740 steel, which is used in high strength applications in the industry but do not have information about its machining characteristics in literature, were found experimentally for different machining parameters (feed per tooth (uncut chip thickness) fz and up- and-down-milling processes). The electric current measurements taken during non-cutting (idle) and cutting conditions were used in power calculations under different machining conditions. It was found that the ps decreased and Ra increased with increasing fz in the up-and down-milling operations and the lower Pc, ps and Ra values were obtained in down-milling than the up-milling operations. The ps values of the material was in between 7.1-15.7 Ws/mm3 for the machining settings used in this study. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ege University School of Dentistry / Ege Üniversitesi Dis Hekimligi Fakültesi Dergisi is the property of Ege University Faculty of Dentistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Developments in machine manufacturing technology necessitate the quality performance of the finished surfaces to be in parallel. The burnishing method is carried out to surfaces in different geometries, and its effect on the normal machined surface quality has been demonstrated by various scientific studies. However, by subjecting the surface to more than one burnishing process, it is limited to obtain sufficient data on the surface properties of the material. In this study, AISI 8620 cementation steel, which is one of the materials commonly used in machine manufacturing, was preferred especially since a toughness in the core, a hard surface resistant to abrasion on the peripheral surface, and a ductile structure in impact work at required. The material was prepared 20 mm diameter with the turning method under the same machining parameters. On 4 of the 5 leveled surfaces prepared; In the examinations and comparisons made after the burnishing process applied from 1 burnishing number to 4 burnishing numbers, the best results were obtained in terms of surface roughness in 2 burnishing operations and surface hardness in 3 burnishing operations. The worst values were obtained in 1 burnishing operation for surface roughness and 4 burnishing operations for surface hardness. [ABSTRACT FROM AUTHOR]

In this study, experimental optimization of factors affecting surface roughness in turning of CW724R brass material was investigated. In the study, Taguchi L9 test was carried out considering cutting speed, depth of cut and feed parameters. S-N values were taken as basis in the evaluation of the test results. Three different cutting speeds, three different depths of cut, and three different feed rates were selected in the study. The experiments were carried out on a CNC lathe under vertical and dry cutting conditions and using carbide inserts. In the study, the average surface roughness (Ra) values were measured and the signal noise values were determined in the Taguchi design. According to the results obtained, it was observed that the feed rate was effective on the surface roughness value. The highest surface quality value (the lowest Ra) was obtained at 181 m/min cutting speed, 0.025 depth of cut and 0.08 mm/rev feed conditions. [ABSTRACT FROM AUTHOR]

The most important problem of composite materials, which have been started to be used in every field of technology, is the ability to perform machining operations such as drilling and cutting. In this respect, in this experimental study, its performance in drilling different composite materials with different reinforcements and thicknesses with drills of different types and different diameters was investigated. Three different types of drills were used in drilling operations, namely HSS, TIN and Carbide. Reinforced composites of different types and properties were used as materials. As a result of the drilling processes, the surface roughness of the drilled surface, drilling performance, hole quality and different cutting parameters were examined depending on the rotation and feed rate. The same drilling conditions were applied for each composite material. All result values obtained were transferred to graphs and tables. In addition, photographs of all samples were taken under Scanning electron microscopy (SEM) and the surface roughness of these photographs was examined. [ABSTRACT FROM AUTHOR]

St37 steel is a frequently preferred material in many structural elements. Parts with low surface roughness values are preferred in terms of fatigue, wear, and corrosion. Since the experimental determination of surface roughness is timeconsuming and costly, these situations can be eliminated by predicting the surface roughness with machine learning methods. In this study, St37 steel was machined in different parameters on a CNC lathe. The surface roughness (Ra, µm) of the experimental samples was measured separately for different process parameters with a profilometer, and 72 different data were obtained. The experimental values obtained were modeled using support vector regression (SVR). The SVR is modeled using two different core functions. These are linear and Gaussian kernel functions. Two different conditions (dry and wet conditions), spindle speed (rpm) and feed rate (mm/rev) were used as input parameters in the models. The output parameter is the surface roughness (Ra, µm). As a result of the designed models, it has been seen that the SVR using the Gaussian kernel function performs better. In this model, the R-square value was obtained as 0.8876, while it was obtained as 0.7231 in the DVR with linear function. Time, material, and cost losses can be reduced by using the SVR with Gaussian core function in industries producing parts from St37 steel by turning. [ABSTRACT FROM AUTHOR]