Metal plakaların balistik performanslarının farklı yüzey mühendisliği uygulamalarıyla geliştirilmesi
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Tarih
2025
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Yayıncı
Karabük Üniversitesi, Lisansüstü Eğitim Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Günümüzde, gelişen mühimmat teknolojileri karşısında zırh sistemlerinin balistik dayanımını artırmak amacıyla yeni malzeme tasarımları ve yüzey mühendisliği teknikleri üzerine yoğun çalışmalar yapılmaktadır. Katmanlı zırh sistemleri, farklı mekanik özelliklere sahip malzemelerin belirli bir düzen içinde birleştirilmesiyle yüksek dayanım ve enerji sönümleme kapasitesi sunan yapılar olarak öne çıkmaktadır. Bu çalışmada, katmanlı zırh sistemlerinin balistik performansını artırmak amacıyla farklı yüzey işlemlerinin etkileri kapsamlı olarak incelenmiştir. Katmanlı zırh sistemlerinde optimum katman kalınlığı belirlenmiş ve bu kalınlıkta hazırlanan numunelere termokimyasal (borlama, plazma nitrürleme) ve mekanik (bilyalı dövme) yüzey işlemleri uygulanmıştır. İnce ve çok sert yüzey katmanları ile daha kalın ve tok iç yapının düzenli olarak tekrarlandığı çok katmanlı yapıların balistik dayanımı artırabileceği öngörülmüştür.
Numuneler, EN 1522 FB7 standartlarına uygun olarak 7,62 x 51 mm AP (zırh delici) mühimmat ile balistik testlere tabi tutulmuş; testler sonucunda numunelerde meydana gelen deformasyonlar, perforasyon durumu ve çöküntü derinlikleri kapsamlı bir şekilde analiz edilmiştir. Yapılan değerlendirmeler, bilyalı dövme işleminin çöküntü derinliğini ve yüzeyde meydana gelen deformasyonu önemli ölçüde azalttığını göstermiştir. Ayrıca, bu işlemin katmanlar arası mekanik etkileşimi iyileştirdiği ve malzeme bütünlüğünü koruma açısından olumlu katkılar sunduğu belirlenmiştir. Öte yandan, termokimyasal yüzey işlemleri uygulanan numunelerde balistik dirençte belirgin bir düşüş gözlemlenmiştir.
Balistik analizlerin yanı sıra, yüzey işlemlerinin malzemenin tribolojik özelliklerine etkileri de detaylı bir şekilde incelenmiştir. Çelik numunelere, 800, 900 ve 1000 °C sıcaklıklarında 6 saat borlama ve 460 ile 535 °C sıcaklıklarında 9 saat plazma nitrürleme işlemleri uygulanmıştır. Ayrıca, 16 A ve 32 A şiddetlerinde bilyalı dövme yüzey işlemi gerçekleştirilmiştir. İşlem görmemiş, borlanmış ve nitrürlenmiş numuneler üzerinde XRD analizleri, optik ve SEM görüntüleme, EDS elementel haritalama, tabaka kalınlığı ölçümleri ve mikro sertlik testleri yapılmıştır. Yüzey pürüzlülük analizleri gerçekleştirilerek karşılaştırmalı değerlendirmeler yapılmıştır. Aşınma testlerinde, işlem görmemiş ve yüzey işlemi uygulanmış numuneler 10 N ve 20 N yükler altında test edilmiştir. Yüzey pürüzlülüğü, hacim kaybı ve sürtünme katsayısı gibi parametreler incelenmiştir. Sonuçlar, yüzey işlemlerinin hacim kaybını önemli ölçüde azalttığını ve borlama ile nitrürleme işlemlerinin daha yüksek aşınma direnci sağladığını göstermiştir. Aşınma testleri, yüzey işlemi uygulanmış numunelerin, işlem görmemişlere kıyasla üstün performans sergilediğini ve hacim kayıplarının azaldığını ortaya koymuştur.
%3,5 NaCl çözeltisinde yapılan korozyon testleri sonucunda, borlama ve nitrürleme işlemi uygulanmış numunelerin korozyon hızlarının, işlem görmemiş numunelere göre belirgin şekilde düşük olduğu gözlemlenmiştir. Korozyon testleri, borlanmış ve nitrürlenmiş numunelerin korozyon dirençlerinin önemli ölçüde arttığını ortaya koymuştur. Testler sonrası aşınma ve korozyon bölgelerinin SEM görüntüleri ve EDS analizleriyle hasar mekanizmaları detaylı şekilde incelenmiştir. Analiz sonuçları, borlanmış numunelerde Fe₂B, nitrürlenmiş numunelerde ise Fe₃N fazlarının oluştuğunu göstermiştir. Borlanmış numunelerde testere dişi formunda bor tabakaları gözlenirken, nitrürlenmiş numunelerde bileşik tabakalar tespit edilmiş ve kalınlıkları ölçülmüştür. Mikrosertlik testleri, borlama sıcaklığı arttıkça yüzey sertliğin arttığını, nitrürlenmiş numunelerde ise her iki sıcaklıkta da birbirine yakın sertlik değerleri elde edildiğini ortaya koymuştur.
Contemporary research is intensively focused on the development of novel material designs and surface engineering methodologies aimed at enhancing the ballistic resistance of armor systems, particularly in response to evolving ammunition technologies. Layered armor systems, characterized by the strategic combination of materials with varying mechanical properties, are particularly noteworthy for their high strength and exceptional energy absorption capabilities. This study comprehensively investigates the influence of various surface treatments on the ballistic performance of layered armor systems. The optimal layer thickness for these systems was determined, followed by the application of thermochemical treatments (boriding and plasma nitriding) as well as mechanical treatments (shot peening) to samples configured at this identified thickness. It is posited that multi-layered structures, which incorporate thin, exceptionally hard surface layers paired with thicker, more ductile inner layers arranged in a regular pattern, possess the potential to significantly enhance ballistic resistance. Ballistic testing was conducted on the samples using 7,62 x 51 mm AP (armor-piercing) ammunition, adhering to EN 1522 FB7 standards. The deformations, status of perforation, and indentation depths of the samples were meticulously analyzed post-testing. The evaluations revealed that the shot peening process considerably mitigated indentation depths and surface deformation. Furthermore, this process was determined to enhance the mechanical interactivity between layers and to positively influence the preservation of material integrity. Conversely, a discernible decline in ballistic resistance was noted in samples exposed to thermochemical surface treatments. In addition to ballistic evaluations, a detailed examination of the impact of surface treatments on the tribological properties of the materials was also undertaken. Steel samples were subjected to boriding at temperatures of 800, 900, and 1000 °C for a duration of 6 hours, alongside plasma nitriding at temperatures of 460 and 535 °C for 9 hours. Shot peening treatments were additionally applied at intensities of 16 A and 32 A. Analyses employing X-ray diffraction (XRD), optical and scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) elemental mapping, layer thickness measurements, and microhardness testing were performed on untreated, borided, and nitrided samples. Surface roughness assessments were executed, leading to comparative evaluations. In wear testing, both untreated and surface-treated samples were subjected to loads of 10 N and 20 N, emphasizing parameters such as surface roughness, wear loss, and friction coefficient. The results indicated that surface treatments significantly reduced wear loss, with boriding and nitriding processes yielding improved wear resistance. Notably, surface-treated samples displayed superior performance compared to their untreated counterparts, exhibiting reduced wear losses. Corrosion tests performed in a 3.5% NaCl solution demonstrated that the corrosion rates for the borided and nitrided samples were markedly lower than those of the untreated samples. The corrosion analysis suggested that borided and nitrided samples achieved significantly enhanced corrosion resistance. Post-test SEM imaging and EDS assessments of wear and corrosion sites facilitated a detailed investigation into the underlying damage mechanisms. The analysis revealed the formation of Fe₂B phases in borided samples and Fe₃N phases in nitrided samples. In borided samples, saw-tooth-shaped boride layers were observed, while compound layers were identified in nitrided samples, with their thicknesses duly measured. Microhardness testing indicated that surface hardness increased with escalating boriding temperatures, whereas nitrided samples exhibited consistent hardness values across the examined temperatures.
Contemporary research is intensively focused on the development of novel material designs and surface engineering methodologies aimed at enhancing the ballistic resistance of armor systems, particularly in response to evolving ammunition technologies. Layered armor systems, characterized by the strategic combination of materials with varying mechanical properties, are particularly noteworthy for their high strength and exceptional energy absorption capabilities. This study comprehensively investigates the influence of various surface treatments on the ballistic performance of layered armor systems. The optimal layer thickness for these systems was determined, followed by the application of thermochemical treatments (boriding and plasma nitriding) as well as mechanical treatments (shot peening) to samples configured at this identified thickness. It is posited that multi-layered structures, which incorporate thin, exceptionally hard surface layers paired with thicker, more ductile inner layers arranged in a regular pattern, possess the potential to significantly enhance ballistic resistance. Ballistic testing was conducted on the samples using 7,62 x 51 mm AP (armor-piercing) ammunition, adhering to EN 1522 FB7 standards. The deformations, status of perforation, and indentation depths of the samples were meticulously analyzed post-testing. The evaluations revealed that the shot peening process considerably mitigated indentation depths and surface deformation. Furthermore, this process was determined to enhance the mechanical interactivity between layers and to positively influence the preservation of material integrity. Conversely, a discernible decline in ballistic resistance was noted in samples exposed to thermochemical surface treatments. In addition to ballistic evaluations, a detailed examination of the impact of surface treatments on the tribological properties of the materials was also undertaken. Steel samples were subjected to boriding at temperatures of 800, 900, and 1000 °C for a duration of 6 hours, alongside plasma nitriding at temperatures of 460 and 535 °C for 9 hours. Shot peening treatments were additionally applied at intensities of 16 A and 32 A. Analyses employing X-ray diffraction (XRD), optical and scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) elemental mapping, layer thickness measurements, and microhardness testing were performed on untreated, borided, and nitrided samples. Surface roughness assessments were executed, leading to comparative evaluations. In wear testing, both untreated and surface-treated samples were subjected to loads of 10 N and 20 N, emphasizing parameters such as surface roughness, wear loss, and friction coefficient. The results indicated that surface treatments significantly reduced wear loss, with boriding and nitriding processes yielding improved wear resistance. Notably, surface-treated samples displayed superior performance compared to their untreated counterparts, exhibiting reduced wear losses. Corrosion tests performed in a 3.5% NaCl solution demonstrated that the corrosion rates for the borided and nitrided samples were markedly lower than those of the untreated samples. The corrosion analysis suggested that borided and nitrided samples achieved significantly enhanced corrosion resistance. Post-test SEM imaging and EDS assessments of wear and corrosion sites facilitated a detailed investigation into the underlying damage mechanisms. The analysis revealed the formation of Fe₂B phases in borided samples and Fe₃N phases in nitrided samples. In borided samples, saw-tooth-shaped boride layers were observed, while compound layers were identified in nitrided samples, with their thicknesses duly measured. Microhardness testing indicated that surface hardness increased with escalating boriding temperatures, whereas nitrided samples exhibited consistent hardness values across the examined temperatures.
Açıklama
Anahtar Kelimeler
Borlama, Plazma nitrürleme, Bilyalı dövme, Balistik, Aşınma, Korozyon., Boriding, Plasma nitriding, Shot peening Ballistics, Wear, Corrosion.
