Study On The Improvement Of The Properties Of Silica Oxide Ceramic Cores For Hollow Blades

With the rapid development of the aviation industry, the ceramic core has an indispensable role in the manufacture of aircraft engine. The ceramic cores contains a series of properties, such as bending strength, shrinkage, open porosity, high temperature deflection and so on. In this paper, the shrinkage of the ceramic core is studied, and taking into account other aspects of performance to meet the performance of production. The properties and components of ceramic core have great relationship, so we focuses on the effect that the Mo mullite, alumina fiber and oxidative phosphorylation on the properties of ceramic core, while the sintering temperature have a great impact on the performance of Ceramic Core, and arrive at a more reasonable si-ntering temperature.In this paper, we use the different methods to test the properties of ceramic core. We test the change length to indicate shrinkage, determine flexural strength by three-point bending, test deflection temperature by double pivot. The open porosity, bulk density and water absorption are measured by water method, and we use the change of quality to indicate the mass burning rate and de-core performance. The results show that:When the temperature increased from 1300℃ to 1330℃, We can find that the tends of firing shrinkage has increased from 0.15% to 0.34%, the flexural strength has increased 1.17 MPa to 5.85 MPa. Also we can find that the deflection temperature has decreased from 2.71 mm down to 2mm. So we select the 1350℃ as the sintering temperature considered from the shrinkage and flexural strength standpoint.With the increase of the content of phosphorus oxide(0-2%), the sintering shrinkage of the ceramic core is gradually decrease from 0.34% to 0.15% and flexural strength has reduced from 5.85 MPa to 0.68 MPa. But the deflection temperature gradually increased from 2mm to 2.94 mm. Shrinkage become smaller with the adding of the phosphorus oxychloride, but the deflection temperature is too large and bending strength is too small, so it is not suitable for phosphorus oxychloride was added to the ceramic core.With the increase of the content of Mo mullite(0-2%), the sintering shrinkage of the ceramic core is gradually decrease and the minimum is 0.21%. The bending strength and high temperature deflection first decreases and then increases, while the maximum value of bending strength is 7.78 MPa and the maximum value of high temperature deflection is 4.58 mm. We can decrease the shrinkage to a certain extent with the add of Mo mullite, but the high temperature deflection are great impoved, so if we considered from the overall performance,we don’t add the Mo mullite to the ceramic core.With the increase of the content of alumina fiber(0 to 4%), the firing shrinkage and high temperature deflection of ceramic core become smaller, while bending strength become enlarger. Among them, the shrinkage of Y-4 was 0.15%, and the bending strength of Y-4 was 13.27 MPa, and the high temperature deflection of Y-4 was 0.9mm.In order to reduce the shrinkage of the ceramic core, it is advisable to select ceramic core that the content of alumina fiber is 4% as the premise of ensuring the other properties..