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| Effect of precipitation preparation temperature on properties of
LaMgAl11O19 thermal barrier coatings |
| CHEN Xiangfen1，LI Chao2 |
| 1 School of mechanical and electrical engineering, xianyang vocational and technical college，xianyang 712000，
China； 2 Institute of metals，Chinese academy of sciences，shenyang 100162，China |
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Abstract In order to improve the properties of LaMgAl11O19 thermal barrier coating for HVAC condenser, the
LaMgAl11O19 thermal barrier coating powder was prepared by precipitation method at precipitation temperature of
60 ℃ and pH value of 11.5. The effects of temperature on the microstructure, half- peak full width and spectral
strength were analyzed. The results show that there are cubic MgAlO4 and hexagonal LaAl2O3 and La2O3 in LaMgAl11O19
powder. The LaMgAl11O19 powder has a hexagonal crystal structure and the particle size is close to 2.7 μm.
These Al2p, La3d, O1s and Mg2p electron diffraction peaks are formed in LaMgAl11O19 powder. After increasing
the sintering temperature, the electron binding energy of each element fluctuates obviously, and the phenomenon of
high energy end deviation appears. With the continuous transformation of LaMgAl11O19 powder into magnetite,
both MgAlO4 and LaAl2O3 form larger half-peak width. When the temperature is blow 1 300 ℃, a higher proportion
of La2O3 bonds are generated during sintering. When the temperature continues to rise above 1 300 ℃, the
number of La2O3 bonds decreases. The LaMgAl11O19 powder has good heat insulation and high temperature resistance,
which is beneficial to improve the sintering resistance and thermal stability of the coating.
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Received: 19 May 2019
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2021, Vol. 31 
