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- MakaleYalnız künye2024Scopus SJRQ1Microstructure, mechanical, and cutting performance properties of B4C and SiC reinforced sandwich composite segments
Islak, Serkan; Çelik, Ertuğrul; Erol, Mümtaz; Houssain, Hasaneen
This study aims to extend the work-life of diamond-cutting segments and to economize the operating cost of diamond-cutting tools. In order to achieve this object, bronze matrix sandwich segments reinforced with SiC and B4C were produced utilizing the hot pressing technique. In the term of the cutting segments, it is favorable that the outer layers are wear-resistant and the middle layer is tough. SEM and XRD analysis were used to determine the microstructural properties. Mechanical properties were evaluated by conducting hardness, wear, cutting performance, and three-point bending tests. The cutting performance of the segments was determined by turning andesite marble. SEM examinations showed that SiC and B4C grains were homogeneously distributed in the bronze matrix. The highest hardness value was 113.9 HB in the B4C reinforced sandwich segment. The reciprocating wear test findings indicated that the matrix exhibited the lowest wear rate in the B4C reinforced sandwich composite segment, followed by the hybrid sandwich composite segment. The lowest amount of cutting loss after turning andesite stone was achieved in the SiC, and B4C reinforced hybrid sandwich composite segment. The cutting performance of the hybrid sandwich composite segment increased by 46.15 % compared to the conventional segment without additives. The highest value of the transverse rupture strength of the specimens was 380 MPa for the B4C reinforced sandwich composite segment and 352 MPa for the hybrid sandwich composite segment. Considering all the tests and analyses, the hybrid sandwich composite segment sample may be the most suitable for diamond-cutting tools.
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İncele - MakaleYalnız künye2024Scopus SJRQ1Effect of boron on microstructure, thermal, and mechanical properties of Ni–B matrix diamond cutting tools
Islak, Serkan; Çelik, Ertuğrul; Houssain, Hasaneen; Danacı, Hacer Cemre
This study examines the impact of adding boron on the microstructural, thermal, and mechanical properties of Ni–B alloy matrix diamond cutting segments, which are created using the hot pressing process. Microstructure was investigated using SEM-EDS and XRD analysis. The high-temperature oxidation behavior of the samples was determined by thermogravimetric analysis. The hardness was quantified employing Vickers hardness testing, as well as, sample densities were derived based on Archimedes' principle. The wear resistance was evaluated using the reciprocating wear test method. A three-point bending test was used to examine how the diamond grains were retained inside the Ni–B matrix. The XRD investigations identified the formation of Ni, Ni3B, and Ni2B phases. The thermogravimetric analysis results showed that Ni–B alloys were exposed to oxidation at elevated temperatures as the B content increased, However, a hardness improvement was observed as the B content increased due to the formation of borides. Furthermore, the tribological investigation reveals that adding the B as reinforcement has a positive effect at a specific amount, where the optimal wear resistance and minimal friction coefficient were evident at 6% B contained sample.
AtıfScopus10WoS10OpenAlex10İncele - Yüksek Lisans TeziAçık Erişim2022Ni esaslı katkı malzemelerinin matris özelliklerine etkisinin araştırılması
Çağdaş Güneş
Her geçen gün daha fazla yayılmaya başlayan Toz Metalurjisi (TM), günümüzün endüstrisinde oldukça yaygın olarak kullanılmaktadır. TM ile üretilen ürünler, proseslerinin daha az sayıda işlem aşaması gerektirmesi ve nispeten daha düşük olan maliyetleri gibi avantajlarından dolayı birçok endüstri tarafından tercih edilmektedir. Son yıllarda farklı sinterleme teknolojilerinin gelişmesi, TM kullanım alanlarını yaygınlaştırmakta ve günümüzde kullandığımız TM ile üretilmiş olan ürünlerin sayısını artırmaktadır. Makine parçaları, kompozit malzemeler, cerrahi implant ve kesici takımlar, yüksek teknoloji malzemeleri ve diğer pek çok ürünün üretilmesinde tercih edilen yöntem olmuştur. Ayrıca tersine mühendislik uygulamalarında CAD ve CAM sistemlerinin gelişmesine bağlı olarak, kısa sürede hedef ürüne doğrudan ulaşılması ve geleneksel imalat yöntemlerine daha az veya hiç ihtiyaç duyulmadığı için artık yüksek bütçeli üretim parkının ve insan hata faktörünün önüne geçilmesi sağlanmıştır. Eklemeli imalat teknolojisinin dünya ve ülkemizde daha popüler olması nedeniyle TM yöntem ve tekniklerinin insan hayatına daha çok etki edeceği aşikârdır. Makine üretim yöntem ve tekniklerinin gelişmesinin yanı sıra ham madde olarak kullanılan tozların gelişimi de kimyasal, mekanik, şekilsel ve yöntemsel olarak devam etmektedir. TM imalat yönteminin imal edilecek numuneye göre iyi seçilmesi kadar seçilen hammaddenin mekanik fiziksel ve kimyasal özellikleri de ürün kalite ve kullanımını önemli oranda etkileyen kilit faktördür. TM ürün imalatında kullanılan hammaddenin türü ve cinsi de birim maliyeti etkileyen en önemli faktördür. Kobalt (Co) TM işlemlerinde ve birçok yüksek teknolojini ürününün (batarya, mıknatıs, kesici takım vb.. ) imalatında mekanik özellikleri bakımından oldukça etkili ürünlerden biridir. Birçok firma Co yerine kullanılabilecek alternatif ürünlerin geliştirilmesi için çalışmalar yapmaktadır. Yapılan bu çalışmada, mekanik açıdan Co'ya alternatif olabilecek Nikel (Ni) esaslı iki adet alaşımlı ticari toz malzeme kullanılarak matrisin mekanik ve mikro yapı özelliklerine etkisi araştırılmıştır. Yapılan deneysel çalışmalar sonucunda Ni esaslı 9062 ve 9045 ticari adlı katkılarını mekanik özellikleri iyileştirerek sertlik ve kırılma mukavemetlerini arttırdığı sonucuna varılmıştır. Kullanılan Ni esaslı alaşım tozların Co alternatifi olarak kullanılabileceği düşünülmektedir. Anahtar Kelimeler: Fe esaslı matris, toz metalurjisi, sıcak presleme, süper alaşımlar
- MakaleAçık Erişim2018Scopus SJRQ3EFFECT OF POST-HEAT TREATMENT ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF Cu-Fe-Co POWDER ALLOY FABRICATED BY HOT PRESSING
Çelik, E.; Aslan, A. K.
In this study, the powder mixture which consists of Cu-Fe-Co was produced by using the method of hot pressing technique. In addition, effect of heat treatment process on microstructure and mechanical properties of this alloy was investigated. Following the hot pressing process applied on the samples, heat treatment was carried out at 950 degrees C for two different dwelling times (90 and 180 minutes). Measured density values were considered as physical characteristics, while hardness and fracture strength values were considered as mechanical characteristics. It was observed that porosity rates of hot pressed samples were decreased by increasing of temperature and pressing parameters. In this study it was observed that Cu was spread in matrix and filled the micro porosities. Hardness values were determined to be decreased as a result of grain growth after heat treatment process. That 4 fold increased elongation % values which were achieved by TRS experiments were observed as well.
AtıfWoS3OpenAlex2İncele - MakaleAçık Erişim2017Scopus SJRQ3The Effect of Porosity and Cu Rate on Microstructure and Mechanical Properties of Co Alternative Powder Metallurgy Compound
Çelik, Ertugrul; Aslan, Ali Kemal
Cu-Ni-MX1480 powder compound were prepared at six different alloy ratios and cold pressed with a pressure of 300 MPa. Then 12 samples were obtained by hot pressing at 700 degrees C with 20 MPa pressure and at 800 degrees C with 30 MPa pressure for 4 minutes in a vacuum atmosphere hot pressing machine. Porosity ratios of samples were calculated by the different between theoretical density and measured density of samples. Effect of porosity on microstructure and mechanical properties were investigated by performing SEM, XRD, hardness measurements and TRS tests. It was observed that as a result of increased hot pressing parameters and increased Cu ratio, porosity ratio was decreased and better mechanical properties achieved.
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