SiAlON Ceramics for the High Temperature Applications: High Temperature Creep Behavior

Abstract

Abstract-Gas turbine engines have been widely used in electricity power generation in industry and aviation. The performance of gas turbine engines is limited by the temperature and strength capabilities of the materials used in the engine. Silicon nitride based ceramics have been expected to be candidates for gas turbine engine components due to their promising mechanical properties at high temperatures. On this basis, over the last 40 years large number of programs in the world has been working to produce ceramic components for gas turbines with the goals of increasing efficiency and lowering emissions. But there are some difficulties that limit the use of structural ceramics based silicon nitride in gas turbine components. Creep performance is one of those problems and creep performance of a material is one of the major factors for determining its high temperature application. In this study creep behavior of SiAlON ceramics, which are solid solutions of silicon nitride ceramics, were investigated at temperatures from 1100 ˚C to 1400 ˚C under stresses from 50 to 150 MPa in air.

Accelerated physical and chemical transformations in ceramics processing

“…33 SiAlONs are ceramics based on the elements Si, Al, O and N, and could be considered as solid solutions of Si 3 O 4 -AlN-Al 2 O 3 . 26,34 The formation of mullite in aluminum silicate systems is often cited as an example of reaction sintering. 26,35 This reaction may also occur during catalytic hydrodesulfurization and the presence of molybdenum in these catalysts may speed up the reaction.…”

Sol-Jel ve Karbotermal İndirgenme-Nitrürleme Kombine Tekniği ile SiAlON Sentezi

“…Bununla birlikte, düşük yoğunluğa sahip, aşınma direnci, termal şoklara dayanma direnci, mekanik yorulma ve sürtünme direnci yüksek olan malzemelerdir. Sahip olduğu özelliklerden dolayı SiAlON seramikleri yüksek sıcaklık endüstrisinde, otomotiv, uzun ömürlü ve yüksek performanslı kesici uç, aşındırma elemanı ve tüm metal/metal alaşımlarının şekillendirilmesi gibi birçok alanda yaygın olarak kullanılmaktadır [6][7][8]. Farklı türlerde SiAlON seramikleri bulunmakla birlikte en iyi bilinen türleri α-ve β-Si3N4 kristal yapılarına karşılık gelen sırasıyla α-ve β-SiAlON seramikleridir.…”