HERMAL SHOCK RESISTANT CERAMIC WITH BORANE PHOSPHOTE ADDITIVE

Bu çalışma; 2003K120470–07 kodlu, Termal şoka dayanıklı, bor fosfat katkılı, hızlı pişirimle elde edilen seramiklerin üretimi adlı DPT tarafından desteklenen projeye katkı amacıyla çalışılmıştır. Bu çalışmada termal şoka dayanabilen seramik türü olarak kordierit ve anorthit fazları seçilmiştir. İlk olarak daha sonra hazırlanacak karışımlarda kullanılmak üzere borofosfat sentezi erçekleştirilmiştir. Elde edilen bor fosfat 1000oC ‘da kalsine edilmiş ve XRD, Kimyasal Analizleri ile karekterize edilmiştir. Diğer yandan (MgO, Al2O3, SiO2) faz diyagramında kordierit fazını en çok kapsayan ve kordieritin oluşabildiği en düşük sıcaklıktaki uygun ötektik noktalar seçilmiştir. Seçilen bu noktaların bileşimleri kaolin, talk, alumina hammaddelerine göre hesaplanmış ve karışımlar hazırlanmıştır. Kordierit için hazırlanan 7 adet karışım iki eşit kısma ayrılmış ikinci kısımlarına %10 BPO4 ilavesi yapılmıştır. Benzer çalışma (CaO, Al2O3,SiO2) faz diyagramında anorthit fazı için de yapılmış ve wollastonit, kaolinit, kalsit kullanılarak 6 adet karışım hazırlanmıştır. Elde edilen 6 adet karışım iki kısma ayrılmış ve yine ikinci kısımlara % 10 BPO4 ilavesi yapılmıştır. Karışımlar presle aynı basınçta şekillendirilmiş ve aynı koşullarda ve aynı ısıtma hızıyla elektrikli fırında kordierit için 1100, 1150, 1200, 1250, 1300, 1350 anorthit için 1000, 1050, 1100, 1150, 1200,1250 oC'a pişirmiştir. Örneklere pişmeden önce DTA ve TG analizleri pişen örneklere ise X ışını kırınımı analizleri uygulanmıştır.This study was performed for 203K120470-07 coded, Manufacture of ceramic that has thermal shocked strength, boron fosfat additive, formed according to fast firing named DTP supported Project. Kordierite and anorthite phases was choosen as thermal shocked strength ceramic types. First of all, boronfosfat was synthesised to use following step. Synthesised boronfosfat was calcined at 1000 OC and its charactarization analysis were performed using XRD and Chemical Analysis. On the other hand, suitable eutectic point of minimum temperature that is the most inclued the kordierte phase and forming cordierte at (MgO, Al2O3, SiO2) phase diagram was choosen. Composition of these choosen points are calculated according to kaoline, talc, alumina raw materials and mixtures are prepared. 7 mixtures that prepared for kordierte, were splited in two equal parts, for its second part %10 BPO4 was added. Likeness study was performed for anorhite phase at (CaO, Al2O3, SiO2) phase diagram and using wallostonite, kaolinit, calsite, 6 mixture was formed. Prepared 6 mixture were splited two parts and %10 BPO4 was added again in second part. Mixture was shaped with pressing at the same pressure and fired using electric furnace at and same condition and the same heating shedule for cordieritre 1100, 1150, 1200, 1250, 1300, 1350 and for anorthite 100, 1050, 1100, 1150, 1200, 1250 OC. Before firing DTA and TG analysis were applied for samples and X-ray diffraction analysis were applied for firing samples

Effects of Boron Phosphate Additive on Ceramics with Anorthite Phase

In this study, the anorthite phase was chosen as a ceramic type that can withstand thermal shock. First, boron phosphate was synthesised, boron phosphate was calcined at 1000°C and characterized by XRD and chemical analyzes. On the other hand, in the phase diagram, the most suitable eutectic points covering the anorthite phase (CaO, Al2O3 , SiO2) and at the lowest temperature at which anorthite can form are selected. 6 mixtures were prepared using wollastonite, kaolinite and calcite. The 6 mixtures prepared were separated into two equal parts and the second parts were added of BPO4 10%. The mixtures were pressed at the same pressure and cooked under the same conditions and at the same heating rate in the electric oven at 1050, 1100, 1150 and 1200°C. DTA and TGA analyzes were applied to the samples before sintering, and XRD analyzes were applied to the sintered samples. According to the test results, the addition of the synthesized BPO4 has shown that the anorthite phases are formed at temperatures well below the theoretical formation temperatures without swelling