Reaktif Spark Plazma Sinterleme Yöntemi İle Alon Seramiklerinin Üretimi Ve Karakterizasyonu
Reaktif Spark Plazma Sinterleme Yöntemi İle Alon Seramiklerinin Üretimi Ve Karakterizasyonu
Dosyalar
Tarih
2012-08-28
Yazarlar
Kanbur, Halide Esra
Süreli Yayın başlığı
Süreli Yayın ISSN
Cilt Başlığı
Yayınevi
Fen Bilimleri Enstitüsü
Institute of Science and Technology
Institute of Science and Technology
Özet
Bu çalışmada optik ve balistik amaçlı kullanımlara uygun AlON seramiklerinin Reaktif Spark Plazma Sinterleme (SPS) yöntemiyle eldesinde SPS sıcaklığı, bekleme süresi, ısıtma hızı ve çeşitli sinterleme dopantları gibi sinterleme parametrelerinin AlON fazı oluşumuna ve bu parametrelerin AlON seramiklerin transparanlığına etkisi incelenmiştir. % 35,7 ve 30 mol AlN, iki farklı Al2O3 (Inframat Advanced Materials ve TM-DAR) ve çeşitli katkılar (MgO, La2O3, Y2O3, MgO+ La2O3, MgO+ La2O3+ Y2O3) ile hazırlanan toz karışımından hareketle iki grupta reaktif SPS deneyleri yapılmıştır. İlk grup deneylerde % 35,7 mol AlN ve Inframat Advanced Materials Al2O3 kullanılarak farklı SPS sinterleme sıcaklıkları (1400-1650 °C), ısıtma hızları (15°C/dak-30°C/dak.), bekleme sürelerinde (15-30-45 °C) % 100 AlON fazına sahip AlON seramikleri elde edilmiştir. İkinci grup deneylerde ise % 30 mol AlN, TM-DAR Al2O3 ve MgO, La2O3, Y2O3, MgO+ La2O3, MgO+ La2O3+ Y2O3 katkılarının eklendiği toz karışımının reaktif SPS tekniği sinterlenmesi ile saydam AlON seramikleri elde edilmiştir. Birinci grup deneylerde, 1650 °C’ de 50 °C/ dk ısıtma hızında, 40 MPa basınç altında, azot atmosferi altında 30 dk bekleme süresi ile SPS ile % 100 AlON fazınıın elde edilmiştir. Bu numune için ölçülen yoğunluk değeri 3,66 g/cm3 olup, sertiği 16,7 ± 0,7 GPa, kırılma tokluğu değeri ise 4,0 ± 0,3 MPa.m1/2 olarak bulunmuştur. İkinci grup deneylerde ise en yüksek ışık geçirgenliği değerine sahip numune, % 0,5 MgO katkısı ile 1650 °C’ de 50 °C/ dk ısıtma hızında, 40 MPa basınç altında, azot atmosferi altında 30 dk bekleme süresi ile sinterlenen numunedir. Bu numune için ölçülen yoğunluk değeri 3,63 g/cm3 olup, sertiği 16,1 ± 0,3 GPa, kırılma tokluğu değeri ise 4,9 ± 0,4 MPa.m1/2 olarak bulunmuştur. Katkılı ve katkısız numuneler kıyaslandığında, katkılı numunelerden % 0,5 MgO içeren numunede, 600 nm dalgaboyunda % 33,9 doğrusal ışık geçirgenliği değeri elde edilmiştir. Reaktif SPS yöntemi ile saydam AlON seramiklerin eldesinde MgO katkısı, SPS sıcaklığının ve bekleme süresinin arttırılması, ısıtma hızının azaltılması ile doğrusal ışık geçirgenliği önemli ölçüde artmıştır.
In this study, AlON ceramics that are suitable for optical and ballistic uses were manufactured by reactive SPS and the effects of sintering parameters such as SPS temperature, holding time, heating rate and various sintering dopants on formation of AlON phase and the effects of this sintering parameters on transparancy of AlON ceramics were analyzed. 35.7 and 30 mol % AlN, two different Al2O3 (Inframat Advanced Materials and TM-DAR) and various additives (MgO, La2O3, Y2O3, MgO+ La2O3, MgO+ La2O3+ Y2O3) were used in reactive spark plasma sintering experiments. In the first group of experiments, AlON ceramics were produced with % 100 AlON phase from 35,7 mol % AlN and Inframat Advanced Materials Al2O3 powder mixtures with different SPS temperature (1400-1650 °C), heating rate (15 °C/min-30 °C/min) and holding time (15-30-45 min). In the second group of experiments, transparent AlON ceramics were obtained by reactive SPS with the powder mixture of 30 mol % AlN, TM-DAR Al2O3 and MgO, La2O3, Y2O3, MgO+ La2O3, MgO+ La2O3+ Y2O3 additives. In the first group of experiments, AlON ceramics with % 100 AlON phase were obtained at 1650 °C with a heating rate of 50 °C/min under 40 MPa pressure under nitrogen gas for 30 min holding time by reactive SPS. For this sample, measured density value was 3.66 g/cm3, hardness value was 16.7 ± 0.7 GPa and fracture toughness value was 4,0 ± 0,3 MPa.m1/2. In the second group of experiments, sample that has the highest inline transmission was sintered at 1650 °C with a heating rate of 50 °C/min under 40 MPa pressure under nitrogen gas for 30 min holding time with 0.5 % wt MgO. For this sample, the density value was measued as 3.63 g/cm3, hardness value was measured 16.1 ± 0.3 GPa, and fracture toughness value was calculated as 4.9 ± 0.4 MPa.m1/2. When samples with and without addives were compared, at 600 nm wavelength % 33.9 inline transmission value is obtained from the sample with 0.5 % wt MgO additive. In line transmittance is improved significantly with MgO additive, increasing SPS temperature and holding time, decreasing heating rate of reactive spark plasma sintering of AlON ceramics.
In this study, AlON ceramics that are suitable for optical and ballistic uses were manufactured by reactive SPS and the effects of sintering parameters such as SPS temperature, holding time, heating rate and various sintering dopants on formation of AlON phase and the effects of this sintering parameters on transparancy of AlON ceramics were analyzed. 35.7 and 30 mol % AlN, two different Al2O3 (Inframat Advanced Materials and TM-DAR) and various additives (MgO, La2O3, Y2O3, MgO+ La2O3, MgO+ La2O3+ Y2O3) were used in reactive spark plasma sintering experiments. In the first group of experiments, AlON ceramics were produced with % 100 AlON phase from 35,7 mol % AlN and Inframat Advanced Materials Al2O3 powder mixtures with different SPS temperature (1400-1650 °C), heating rate (15 °C/min-30 °C/min) and holding time (15-30-45 min). In the second group of experiments, transparent AlON ceramics were obtained by reactive SPS with the powder mixture of 30 mol % AlN, TM-DAR Al2O3 and MgO, La2O3, Y2O3, MgO+ La2O3, MgO+ La2O3+ Y2O3 additives. In the first group of experiments, AlON ceramics with % 100 AlON phase were obtained at 1650 °C with a heating rate of 50 °C/min under 40 MPa pressure under nitrogen gas for 30 min holding time by reactive SPS. For this sample, measured density value was 3.66 g/cm3, hardness value was 16.7 ± 0.7 GPa and fracture toughness value was 4,0 ± 0,3 MPa.m1/2. In the second group of experiments, sample that has the highest inline transmission was sintered at 1650 °C with a heating rate of 50 °C/min under 40 MPa pressure under nitrogen gas for 30 min holding time with 0.5 % wt MgO. For this sample, the density value was measued as 3.63 g/cm3, hardness value was measured 16.1 ± 0.3 GPa, and fracture toughness value was calculated as 4.9 ± 0.4 MPa.m1/2. When samples with and without addives were compared, at 600 nm wavelength % 33.9 inline transmission value is obtained from the sample with 0.5 % wt MgO additive. In line transmittance is improved significantly with MgO additive, increasing SPS temperature and holding time, decreasing heating rate of reactive spark plasma sintering of AlON ceramics.
Açıklama
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2012
Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2012
Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2012
Anahtar kelimeler
SPS,
AlON,
SPS,
AlON