High Temperature Anti-deformability of Composite Modified Ceramic Shell with Y₂O₃ and Al-Si-Mg Series Mineralizer

Abstract

In order to improve the high temperature anti-deformability of ceramic shells for single crystal blade, composite modified ceramic shell specimens of Y2O3 and Al-Si-Mg series mineralizer were prepared with addition of 2% (mass fraction, the same below), 4% and 6%, then the thermal expansion and high-temperature self-loaded deformation of specimens were studied. The results show that high temperature thermal expansion and self-loaded deformation firstly reduced and then increased with the increase of the addition, when content is 4%, the test improvement is obtained, the minimum values of the linear expansion and high-temperature self-loaded deformation are 0.66% and 0.55% at 1500℃, and the average decrease efficiency of the composite mineralizer on high-temperature self-loaded deformation is twice that of thermal expansion. The mechanism of composite mineralizer to modify the shell is to prevent the viscous flow of glass phase by bridging mullite as micro framework and fine globular yttrium aluminum garnet (YAG) inserted between crystals, to jointly improve anti-deformation ability of the shell. However, adding too much, it will produce a large number of glass phase, weakening high temperature performance of the shell.

Keywords

• composite mineralizer
• thermal expansion
• high-temperature self-loaded deformation
• mullite
• yttrium aluminum garnet