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Öğe Hardness and wear behaviours of al matrix composites and hybrid composites reinforced with B 4 C and SiC(Springer Nature, 2019-01-15) Çelik, Yahya Hışman; Kılıçkap, ErolThe conversion into the desired shape of the metal powders using Powder Metallurgy (PM) method enables economically mass productions. This case allows producing parts with complex and high dimensional accuracy with no machining. In this study the composites and hybrid composites with Al matrix were produced using PM method with different ratios B4C and SiC. Microhardness and wear experiments of the produced composites were investigated. Wear experiments were performed at a constant speed of 0.5 m/s, application loads of 5, 10 and 15 N and sliding distances of 250, 500, and 750 m. Then, SEM images of composites and hybrid composites were captured. The increase of the reinforcement ratio in the composites contributed to the increase of the hardness. The highest hardness value was computed as 58.7 HV from 16% B4C reinforced composite. In addition, the increase in the reinforcement ratio contributed to the increase of the wear resistance. The increase in the load and sliding distance also increased the wear. The minimum weight loss was calculated as 18 mg from 5 N load, 250 m sliding distance and 16% SiC reinforced composite.Öğe Investigation of wear behaviours of Al matrix composites reinforced with different B4C rate produced by powder metallurgy method(Elsevier, 2017-09) Çelik, Yahya Hışman; Seçilmiş, KübraIn this study, the effects of wear behaviours of Al matrix composites reinforced with different B4C rate produced by powder metallurgy method were investigated. Al and B4C powders with purity of 99.9% and sizes of 25–44 µm were prepared as pure Al, 4% B4C/Al, 8% B4C/Al, 12% B4C/Al and 16% B4C/Al. After these prepared mixtures were pressed under 350 MPa, they were sintered for 90 min at 580 °C in atmospheric environment. Microhardness and wear tests of the produced samples were carried out. Wear experiments of these composites were performed with specially manufactured test equipment at different application loads (5 N, 10 N and 15 N), different sliding distances (250 m, 500 m, 750 m and 1000 m) and a constant speed of 0.46 m/s. In addition, optical microscope, SEM, EDS analyses were used to determine the microstructural changes in the worn and unworn surface of the manufactured composite materials. The results of experimental studies show that the increasing the B4C reinforced rate in composites with Al matrix has led to increase of the hardness and to reduce of the wear loss.Öğe Effects of natural hard shell particles on physical, chemical, mechanical and thermal properties of composites(SAGE Journals, 2021-05-31) Çelik, Yahya Hışman; Çelik, Kadir Serdar; Kılıçkap, ErolShelled herbal foods are widely consumed. The evaluation of the shells of these foods is important due to their features such as low cost, ease of recycling and environmental friendliness. In this study, hazelnut shell (HS), pistachio shell (PS), and apricot kernel shell (AKS) were brought to powder particles by grinding to dimensions of 300–425 µm. Some of the powder particles were converted into ash at 900°C. The amounts of cellulose, ash, humidity, and metal in these particles via chemical analyses were determined, while their structural properties via X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) analyses. Composite materials were produced by adding 15 wt.% to the polyester matrix material from these powder particles and ashes. Compression strength, hardness, specific weight, and thermal conductivity of these composites were analyzed. The lowest and highest humidity, ash, cellulose, hemicellulose, and lignin ratios in powders showed differences depending on the type of powders. The amount of Sn and K in the HS, PS, and AKS powders were close to each other, while the amount of Ca, Na, Mg, Fe, Mn, Cu, Zn and Si was higher in AKS powder. The reinforcement adding to the polyester increased the compression strength, hardness, specific weight and thermal conductivity properties.Öğe Numerical investigation of fatigue behavior of non-patched and patched aluminum/composite plates(Ahmet ÇALIK, 2021-12-20) Adin, Hamit; Sağlam, Zeyni; Adin, Mehmet ŞükrüIn this study, the fatigue behavior of composite patched and non-patched Al 5083 aluminum plates was numerically investigated. Al 5083 Aluminum plates with semi-circular notched (2, 3 and 4 mm long cracked) and "V" notched (30°, 45° and 60° angled) were used in the analyzes. Mechanical properties of Al 5083 Aluminum plate, DP460 type adhesive of produced by 3M and [0°]8 glass fiber reinforced composite patch material was used for the study. The Finite Element Method was applied for numerical study. Numerical analyzes were performed with the Ansys version 15.0 Workbench Package program. As a result of the numerical study, the highest fatigue life (1593.2 N) is seen on the 30° angled "V" notched and patched specimen. However, the fatigue life in non-patched specimen (30° angled "V" notched) was found to be 277.69 N. Thus, the study revealed that the composite patch's contribution is very important.Öğe AL/SiC Kompozit malzemenin delinmesinde yüzey pürüzlülüğünün bulanık mantıkla modellenmesi(Dicle Üniversitesi, 2016) Çelik, Yahya Hışman; Yenigün, Burak; Kılıçkap, ErolBu çalışmada, sıkıştırma döküm yöntemiyle üretilmiş SiC takviyeli Al esaslı kompozit kullanılmıştır. Üretilen kompozit malzeme farklı uç açılarına sahip HSS takımlar kullanılarak; farklı delme parametrelerinde delme işlemine tabi tutulmuştur. Her bir delme işlemi için delme yüzeylerinin yüzey pürüzlülükleri ölçülmüştür. Elde edilen veriler bulanık mantığa uygulanarak yüzey pürüzlülüğünün modellenmesi yapılmıştır. Veriler incelendiğinde, en iyi yüzey pürüzlülüğü 90˚ uç açısına sahip takım kullanılarak 1500 dev/dak dönme devri ile 0.05 mm/dev ilerleme değerinde elde edilmiştir. En kötü yüzey pürüzlülüğü ise 118˚ uç açılı takımın 2000 dev/dak dönme devri ile 0.15 mm/dev ilerleme değerinde elde edilmiştir. Bulanık mantık kullanılarak elde edilen tahmini değerlerin deney sonuçlarına yakın değerler verdiği görülmüştürÖğe Bal peteği sandviç kompozitlerin düşük hızlı darbe davranışlarının araştırılması(Yunus Emre Enstitüsü, 2017) Topkaya, Tolga; Solmaz, Murat YavuzBal peteği sandviç komozitler ileri mühendislik uygulamalarında önemli bir yapı elemanı olarak kullanılırlar. Bu nedenle darbe etkisi atında nasıl bir davranış sergileyeceklerinin bilinmesi diğer yükler kadar kritiktir. Gerçekleştirilen çalışmada bal peteği sandviç kompozitlerin düşük hızlı darbe yüklemesine karşı davranışları deneysel olarak araştırılmıştır. Bal peteği sandviç kompozitlerin tasarım parametrelerinin tamamına yakınının etkisi incelenmiştir. Sonuçlar bal peteği hücre yüksekliğinin mukavemet üzerinde bir etkisi olmadığının gösterirken numunenin darbe davranışını en çok etkileyen parametrenin yüzey malzemesi kalınlığı olduğunu göstermiştir. Numune yüzey malzemesi kalınlığı arttıkça en belirgin mukavemet artışı karbon fiber takviyeli kompozit yüzey malzemesi kullanılan modellerde görülmüştür. 10 J darbe enerjisinde bütün yüzey malzemesi tipleri için 0.5 mm yüzey malzemesi kalınlığın sahip numunelerin üst yüzey malzemeleri delinmiştir.Öğe Investigation of wear behavior of aged and non-aged SiC-reinforced AlSi7Mg2 metal matrix composites in dry sliding conditions(SpringerLink, 2020-01) Çelik, Yahya Hışman; Kılıçkap, Erol; Demir, Mehmet Emin; Kalkanlı, AliMetal matrix composites (MMCs) with their splendid mechanical properties have been specifcally designed for use in felds such as aerospace and aviation. The presence of hard ceramic particles in MMC increases the hardness of the matrix product and decreases its coefcient of friction. Therefore, the wear resistance is improved. Moreover, the mechanical properties of these composite materials can be improved by applying heat treatments. In this study, AlSi7Mg2 MMCs with 15 wt% SiC reinforcement were produced by squeeze casting technique. Some of the composites were aged by heat treatment. Hardness values of aged and non-aged composites were compared. In addition, abrasive wear behaviors of these composites were investigated on pin-on-disk device, depending on the load (7, 12 and 17 N), the sliding speed (0.2, 0.3 and 0.4 m/s) and the sliding distance (700, 1000 and 1300 m). Worn surfaces were also analyzed by scanning electron microscopy (SEM). As a result of the analyses, it was determined that both the hardness values and the wear resistance were higher in the composites subjected to aging treatment. Furthermore, it was observed that the increase in the applied load led up to the weight loss. The increase in the sliding distance increased both friction coefcient and weight loss. The increase in sliding speed also made way for the friction coefcient but ensured less weight loss. When SEM images were examined, it was ascertained that deformation and tribo-surface formation had a signifcant efect on weight losses.
