Atık cam ve deniz kabuklarından CaO-Al2O3-SiO2 (CAS) esaslıseramiklerin üretim imkânlarının araştırılması ve özelliklerinin incelenmesi
The investigation of CaO-Al2O3-SiO2 (CAS) based ceramics production conditions and its properties by using sea shell and waste glass
Yazar: ESRA TAVUKÇUOĞLU
Danışman: PROF. DR. ŞENOL YILMAZ
Sakarya Üniversitesi / Fen Bilimleri Enstitüsü / Metalurji ve Malzeme Mühendisliği Ana Bilim Dalı
Derece: Yüksek Lisans, 2023
Konu: Metalurji Mühendisliği = Metallurgical Engineering
Dizin: Atık camlar = Waste glasses ; Deniz kabukları = Shellfish ; Faz analizi = Phase analysis ; Taramalı elektron mikroskobu = Scanning electron microscope ; X ışını = X ray

Özet:
Bu tez çalışmasında deniz kabuğu ve atık camlardan CaO-Al2O3-SiO2 (CAS) esaslı seramiklerin üretim imkânlarının araştırılması amaçlanmıştır. Deniz kabuğu ve atık pencere camının yanı sıra Al2O3, SiO2 ve CaF2'de ilave edilerek hazırlanan 3 farklı bileşimden ergitme yöntemi ile cam fritler elde edilmiştir. Cam fritler bilyeli değirmende öğütülüp elenmiş (<45μm) ve hidrolik pres ile şekillendirilerek silindirik ve dikdörtgen numuneler üretilmiştir. Bu numuneler 850°C, 900°C, 950°C ve 1000°C'de 2 saat sinterlenerek CAS esaslı seramikler elde edilmiştir. Sinterlenen numunelerin faz analizleri X-ışını difraksiyonu (XRD) ile gerçekleştirilmiştir ve ardından mikroyapı incelemeleri de taramalı elektron mikroskobu (SEM) ile yapılmıştır. Ayrıca pişme küçülmesi, yoğunluğu, molar hacim, ağırlık kaybı, üç nokta eğme, DTS, mikrosertlik, XRF analizleri ile yapısal ve mekanik özellikleri incelenmiştir. Elde edilen veriler deniz kabuğu ve atık pencere camlarından CAS esaslı seramiklerin üretimlerinin mümkün olduğunu göstermiştir.

Abstract:
In this study, it was aimed to investigate the production possibilities of CaO-Al2O3-SiO2 (CAS) based ceramics from seashell and waste glass. For this purpose, three different compounds were prepared and Al2O3, SiO2 and CaF2 were added to these compounds as pure raw materials to seashell and waste glass. After that, the mixture was also placed directly in an alumina crucible and then melted at a temperature of 1500 °C using an electric furnace and then poured into a graphite mold and water. The frits were then ground and sieved to produce fine CAS powders (< 45 μm). The produced glasses were ground, sieved and shaped by hydraulic press. Cylindrical and rectangular samples coded CS-1, CS-2, CS-3 were obtained after pressing. All samples were sintered at 850°C, 900°C, 950°C and 1000°C. Linear shrinkage, bulk density, molar volume (Vm), micro hardness, X-ray diffraction (XRD), XRF and scanning electron microscope (SEM) of sintered samples were investigated. The results obtained are summarized below. 
a) According to XRD analysis, it was determined that the structure of the glass samples melted and cast at 1500°C was amorphous. 
b) In density tests, density values were measured as between 1.47-2.49 g/cm3 for CS-1, 2.22-2.65 g/cm3 for CS-2 and 2.31-2.67 g/cm3 for CS-3. As the amount of seashell increases the density values increase while the amount of pores decreases. 
c) An wavy change was observed in the firing shrinkage. The shrinkage decreased at 1000 °C due to the completion of the reactions to a large extent. 
d) No significant weight loss was observed depending on the temperature and the addition of seashells. This is an indication that the calcination process of seashells is efficient and effective. 
e) Molar volume is inversely proportional to density. It is seen that the molar volume value decreases as the density increases. 
f) Bending strength ceramic values have been obtained as between 21.34-124.94 MPa in CS-1 coded glass-ceramic, 49.01-107.21 MPa in CS-2 coded glassceramic and 79.51-119.21 MPa in CS-3 coded glass-ceramic. 
g) It was determined that increasing the heat treatment temperature and the amount of seashell did not have a significant effect on the DTS test results of the samples. 
h) The hardness values measured for CS-1 vary between 490-526 HV0.05, 439-777 HV0.05 for CS-2 and 407-945 HV0.05 for CS-3. CS-3 CAS glass-ceramic sintered at 850°C has the highest hardness value. As the amount of seashell
increased, the microhardness values also increased. 
i) Cuspidin, Gehlenite and Nephelin phases were determined as the main phases in XRD analyzes of materials after heat treatment. While the Andesin phase was found at 900°C and 950°C in the CS-1 coded material, three main phases and Anorthite and Albite phases were also determined at 1000°C. Peak intensities of the Gehlenite phase increased as the heat treatment temperature increased in CAS glass-ceramics.
j) Pores and crystal formations were observed in glass-ceramic microstructures. The results obtained showed that it is possible to produce CAS-based ceramics from seashells and waste window glass. It is thought that CAS glass-ceramics can be used as building materials.