Dişli sistemlerinde çelik malzemelerin eşlenik çalışma performansının artırılmasına yönelik çeşitli kaplama yöntemlerinin belirlenmesi ve performans analizi
Determination and performance analysis of various coating methods to enhance the conjugate working performance of steel materials in gear systems
- Tez No: 964430
- Danışmanlar: PROF. MEHMET FIRAT
- Tez Türü: Yüksek Lisans
- Konular: Makine Mühendisliği, Metalurji Mühendisliği, Mechanical Engineering, Metallurgical Engineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2024
- Dil: Türkçe
- Üniversite: Sakarya Üniversitesi
- Enstitü: Fen Bilimleri Enstitüsü
- Ana Bilim Dalı: Makine Mühendisliği Ana Bilim Dalı
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 93
Özet
Günümüzde mekanik sistemlerde verimlilik, dayanıklılık ve maliyet dengesini sağlamak, mühendislik uygulamaları açısından kritik öneme sahiptir. Bu doğrultuda, güç aktarım sistemlerinde kullanılan dişli mekanizmalarının malzeme seçimi ve mekanik özellikleri, sistemin performansı üzerinde doğrudan belirleyici olmaktadır. Sonsuz vida-dişli mekanizmaları, yüksek iletim oranı sağlayabilmeleri ve kompakt yapıları sayesinde özellikle güç aktarım sistemlerinde yaygın olarak tercih edilen dişli türlerinden biridir. Bu sistemlerde, genel uygulama pratiğinde, sonsuz vida çelikten, karşılık gelen dişli ise bronz alaşımlardan üretilmektedir. Bu malzeme seçimi, temel olarak bronzun çeliğe karşı düşük sürtünme katsayısına ve iyi bir aşınma davranışına sahip olmasıyla ilişkilidir. Ancak günümüzde artan hammadde maliyetleri, sürdürülebilirlik kaygıları ve tedarik problemleri, bu geleneksel yaklaşımın yeniden değerlendirilmesini zorunlu kılmaktadır. Özellikle alüminyum bronz malzemenin birim maliyetinin çeliğe göre yaklaşık 20 kat daha yüksek olması, büyük ölçekli üretimlerde toplam maliyeti ciddi biçimde etkilemekte ve sistemin ekonomik verimliliğini düşürmektedir. Buna ek olarak, bronzun mekanik dayanımının çeliğe kıyasla sınırlı olması da yüksek yük altında çalışan sistemlerde işlevsel bir kısıt ortaya çıkarmaktadır. Bu bağlamda, çalışmanın temel motivasyonu; çelik-çelik eşlenik dişli sistemlerinin yüzey kaplama teknolojileri ile desteklenerek hem aşınma performansının artırılması hem de ekonomik sürdürülebilirliğin sağlanmasıdır. Bu amaçla DLC, sert krom, nikel-tungsten (Ni-W) ve katı film gibi farklı yüzey kaplamaları çelik numuneler üzerine uygulanmış, bu kaplamaların tribolojik performansları sistematik bir şekilde analiz edilmiştir. Deneysel aşamada Vickers mikrosertlik ölçümleri, yüzey ve kesit SEM incelemeleri, kuru ortamda aşınma testleri ve sürtünme katsayısı (COF) ölçümleri gerçekleştirilmiştir. Ayrıca aşınma sonrası yüzey morfolojileri detaylı olarak değerlendirilerek, her bir kaplamanın çelik yüzeyler üzerindeki koruyucu etkisi ve yapısal bütünlüğü ortaya konmuştur. Elde edilen veriler, bazı kaplama türlerinin çelik-çelik temas durumunda aşınma direncini ciddi oranda artırdığını ve sürtünme katsayısını düşürdüğünü göstermektedir. Bu bulgular, bronz yerine çelik kullanımının uygun kaplama teknolojileriyle desteklenmesi halinde mümkün olabileceğini göstermektedir. Sonuç olarak, bu çalışma sonsuz dişli malzemesi olarak bronz kullanıldığı durumda sistemde ortaya çıkan dezavantajları ortadan kaldırmak için ekonomik bir alternatif sunmakta hem de literatürde sınırlı olarak ele alınmış çelik-çelik eşlenik sonsuz vida-dişli sistemlerine dair özgün ve uygulanabilir teknik veriler kazandırmaktadır.
Özet (Çeviri)
In today's engineering practices, efficiency, durability, and cost-effectiveness are core concerns in the design and operation of mechanical transmission systems. Among various gear mechanisms, worm gear systems are widely employed due to their ability to provide high reduction ratios within compact geometries. Traditionally, the worm is manufactured from steel, while the mating worm wheel is typically produced from bronze alloys. This conventional material pairing has long been favored owing to bronze's advantageous tribological properties, particularly its low coefficient of friction (COF) and satisfactory wear resistance when operating against steel. However, rising raw material costs, global supply chain disruptions, and growing sustainability concerns have prompted a critical reassessment of material selection in such systems. In particular, bronze's significantly higher cost—up to 20 times more expensive per unit than steel—introduces major economic burdens in large-scale production, thereby reducing the overall efficiency and feasibility of these systems. Moreover, bronze's limited mechanical strength compared to steel restricts its applicability in high-load applications, thus creating functional limitations. These factors underline the necessity of exploring alternative solutions that maintain or enhance performance while improving economic and structural efficiency. This study is motivated by the need to develop a technically and economically viable solution that replaces bronze with steel in conjugate gear applications, particularly in worm gear mechanisms. The primary research hypothesis is that the wear and friction limitations associated with steel-on-steel contact can be significantly mitigated through the use of advanced surface coating technologies. By applying protective coatings to steel components, it may be possible to enhance tribological performance, improve wear resistance, and reduce friction to levels comparable with or superior to traditional bronze-steel pairings. The main objective of this thesis is to investigate the tribological behavior of coated steel surfaces in a steel-steel conjugate configuration and to determine the effectiveness of various surface coatings in enhancing mechanical performance. The study specifically evaluates the suitability of DLC (Diamond-Like Carbon), hard chrome, Ni-W (nickel-tungsten alloy), and solid film coatings in terms of their protective properties, structural integrity, and overall contribution to system efficiency. To assess the performance of the selected coatings, a comprehensive experimental program was designed and executed. Steel specimens were coated with four different commercially and industrially viable coatings: DLC, hard chrome, Ni-W alloy, and solid film. The coated samples underwent a series of standardized tests aimed at evaluating their hardness, wear resistance, surface morphology, and frictional behavior. First, surface and cross-sectional analyses were performed using Scanning Electron Microscopy (SEM) to observe coating uniformity, thickness distribution, and any potential defects. Vickers microhardness testing was conducted to measure the hardness improvements introduced by the coatings. Subsequently, tribological behavior was examined through dry sliding wear tests based on the pin-on-disc method. These tests aimed to determine both the volume loss due to wear and the coefficient of friction throughout the sliding process. Post-wear surface morphology was again analyzed using SEM to investigate wear mechanisms and surface damage characteristics. The experimental findings revealed that each coating exhibited unique tribological characteristics, but all showed improvements over uncoated steel in terms of wear resistance and COF reduction. DLC, in particular, demonstrated superior performance by offering both low friction values and high wear resistance, attributable to its high hardness and self-lubricating nature. The Ni-W alloy coating also presented promising results due to its dense microstructure and high surface hardness. Hard chrome, while providing moderate frictional performance, showed excellent wear resistance under specific conditions. The solid film coating was effective in reducing COF but was found to be less durable under prolonged loading conditions. Overall, the coatings significantly mitigated the limitations of steel-on-steel contact, validating the hypothesis that surface treatments can effectively transform conventional steel components into high-performance alternatives to bronze-based systems. The improvements in surface hardness and the ability of the coatings to resist material transfer and adhesive wear played a central role in the performance enhancements observed. In addition to the technical performance, the economic and environmental implications of transitioning from bronze to coated steel components must be considered. The drastic cost difference between steel and bronze makes the former a more attractive choice, especially when enhanced with high-performance coatings. Moreover, reducing the dependency on non-ferrous metals like bronze, which require energy-intensive extraction and processing methods, contributes to the overall sustainability of manufacturing operations. Coated steel alternatives offer a pathway to more eco-friendly production systems, minimizing resource depletion while maintaining high functionality. Such transitions are particularly vital in the current era where environmental compliance and carbon footprint reduction are becoming industry-wide priorities. This study provides valuable experimental evidence to support the application of surface coatings in gear mechanisms involving steel-on-steel contact. The results indicate that a properly selected coating not only enhances mechanical properties such as wear resistance and friction control but also allows for significant cost savings by enabling the replacement of bronze with steel. From an industrial perspective, the ability to switch to steel components without compromising system performance offers considerable advantages in terms of both sustainability and operational efficiency. Furthermore, this research contributes to the existing body of knowledge by focusing on an area that remains underrepresented in the literature: conjugate steel gear systems in worm gear applications. The comparative analysis of four different coatings, supported by detailed experimental data, serves as a practical guide for engineers and researchers involved in material selection and surface engineering. The outcomes of this study are directly applicable to a wide range of mechanical systems that rely on gear-based motion transmission. Industries such as automotive, aerospace, robotics, heavy machinery, and defense can benefit from these findings by integrating coated steel solutions into their gear assemblies. For instance, in automotive powertrains and steering systems where worm gears are prevalent, enhanced wear resistance can extend the service life and reduce maintenance costs. Similarly, in defense applications where reliability under extreme load conditions is crucial, the use of coated steel provides both robustness and efficiency. The selection criteria and empirical data presented in this thesis can thus serve as a practical reference for engineers and decision-makers in industrial settings. While this study has demonstrated promising results, several avenues remain open for further research. Future studies could explore the long-term durability of coatings under cyclic loading and varying temperature conditions to simulate real-world operational environments. Additionally, the combination of multiple coatings (hybrid or multilayer systems) could be investigated to achieve synergistic performance improvements. It would also be beneficial to develop predictive wear models using computational simulations supported by the empirical data gathered in this research. Such models would allow for more accurate service life estimations and material optimization in early design stages. Further collaboration with industry partners could also accelerate the implementation of these findings into commercial products. In conclusion, the findings of this thesis highlight the potential of surface coating technologies to extend the functional capabilities of steel gear components in demanding applications. By successfully addressing both tribological performance and economic feasibility, this study lays the groundwork for broader adoption of coated steel materials in gear transmission systems, particularly in scenarios where bronze usage is no longer sustainable. The results offer both academic insights and real-world applicability, positioning this research as a valuable contribution to modern mechanical design practices.
Benzer Tezler
- Silecek sistemlerinde kullanılan dişli çark mekanizmaları için gürültü analizi
The acoustic analysis of the gearbox of the wiper system
MUSTAFA ERDEM KAFALI
Yüksek Lisans
Türkçe
2023
Makine Mühendisliğiİstanbul Teknik ÜniversitesiMakine Mühendisliği Ana Bilim Dalı
DR. ÖĞR. ÜYESİ ZEYNEP PARLAR
- Vites dişli çeliğinin KRTD-bor yöntemi ile borlanması
Boriding of transmission gear steel via CRTD-bor
ALAADDİN CEM OK
Yüksek Lisans
Türkçe
2018
Metalurji Mühendisliğiİstanbul Teknik ÜniversitesiMetalurji ve Malzeme Mühendisliği Ana Bilim Dalı
DOÇ. DR. GÜLDEM KARTAL ŞİRELİ
- The effect of barrier materials and getter material on pressure increase of vacuum insulated systems
Vakumlu yalıtım sistemlerinde bariyer malzemeler ve getter malzemesinin basınç artışına etkisi
AYŞE ÇELİK
Yüksek Lisans
İngilizce
2003
Polimer Bilim ve Teknolojisiİstanbul Teknik ÜniversitesiPolimer Bilim ve Teknolojisi Bilim Dalı
PROF. DR. I. ERSİN SERHATLI
- Modeling of the lateral load resistance of masonry infilled frames with innovative steel ties
Yenilikçi çelik bağlar içeren yığma dolgu duvarlı betonarme çerçevelerin yatay yük direncinin modellenmesi
MIRSALAR KAMARI
Yüksek Lisans
İngilizce
2016
İnşaat Mühendisliğiİstanbul Teknik Üniversitesiİnşaat Mühendisliği Ana Bilim Dalı
YRD. DOÇ. OĞUZ GÜNEŞ
- Metal plakaların balistik performanslarının farklı yüzey mühendisliği uygulamalarıyla geliştirilmesi
Improving the ballistic performance of metal plates through different surface engineering applications
VAHAP NECCAROĞLU
Doktora
Türkçe
2025
Makine MühendisliğiKarabük ÜniversitesiMakine Mühendisliği Ana Bilim Dalı
PROF. DR. OKAN ÜNAL