Zirconia Hollow Over Spherical Powder Used As Thermal Barrier Coatings

With the development of the high-performance, long-lifetime, high reliability and low-cost aero-engine, the thermal barrier coatings is one of the most ideal methods for solving these problems. Zirconia has low thermal conductivity and high thermal expansion coefficient close to super-alloy substrate. It is an ideal material used as thermal barrier coatings applicable to high temperature. Plasma spraying is the most often used method for depositing thermal barrier coatings. To spray the coatings, It is high request on chemical component uniformity, good fluidity, particle size distribution moderate. So, we study the powder on all kinds of characters.The paper study characters on Zirconia hollow over spherical powder with spray-drying and high temperature spherical way. t also studies coating characters. It studies fluidity, powder appearance, thermal resistance and combination with a bond coatings and other capability of the Zirconia hollow over spherical powder by means of optical microscopy, scanning electron microscopy (SEM). We also studies the effects of particle-sizes distribution on Zirconia hollow over spherical powder fluidity. We have drawn some conclusions:1) Zirconia hollow over spherical powder that is prepared by the paper's way are well and truly hollow and spherical. Zirconia hollow over spherical powder's hollow and spherical is very high. It is 83.2%. Its main characteristic is similar to the products of America's METCO Company. Zirconia hollow over spherical powder has a lot of merit, for example: good particle-sizes distribution, good fluidity, 69 s/50g, low thermal conductivity and so on. It's an ideal thermal barrier coatings material.2) This thermal barrier coatings by this way have a high combination with a bond coat. The coatings can resistant thermal shake and thermal (No breaking off when heating circulate 250) .3) In selected particle-sizes distribution, 50-63μm Zirconia hollow over spherical powder's fluidity are better, 60s/50g.4) In selected distribution project, 63-75μm Zirconia hollow over spherical powder percent 10% on quality,50-63μm powder occupy 45% on quality,11-50μm powder occupy 45% on quality, the powder fluidity is better and is 79s/50g.5) The effect of less than 50μm powder on the whole fluidity of blend powder material is very strong. In selected distribution project, less than 11μm powder joined, on quality percent l%,it hardly effect the whole fluidity of blend powder and is 79s/50g.On quality percent 2%, fluidity reduce to 99s/50g.On quality percent 4%, fluidity is disconnected. On quality percent 6%, powder hardly flow.