等离子喷涂Al2O3-TiO2系涂层的相组成定量分析

采用大气等离子喷涂制备了TiO2质量百分比分别为0%、3%、13%、20%、40%5种Al2O3-TiO2系涂层.利用Rietveld法以及添加标样的办法对喷涂前后的材料物相进行了定量分析,探讨了材料的相变过程.经喷涂,大部分α-Al2O3转变为亚稳相γ-Al2O3,喷涂粉末中存在的TiAl2O5保留在涂层中,有四种涂层中还形成了非晶相.涂层中的非晶相的含量先随着TiO2增加而增加,在TiO2的质量百分比为13%时最多,而后下降.这个趋势是喷涂粉末中Al2O3含量以及喷涂过程中材料的冷却速率共同作用的结果.

Quantitative determination of phase composition in plasma sprayed Al2O3-TiO2 coatings

Al2O3-TiO2 coatings were prepared by atmospheric palsama spraying using Al2O3-TiO2 powders with 0%,3%,13%,20%,40% TiO2,respectively.The phase composition of powders and coatings were quantitatively determinated by the combination of the Rietveld method and the internal standard method.The phase transformation of materials during spraying was discussed.The great mass of α-Al2O3 transformed to metastable γ-Al2O3,and TiAl2O3 remained in the coatings after spraying.Amorphous phase was found in four coatings.The weight fraction of amorphous phase was increased with the TiO2,until the the weight fraction of TiO2 was 13%,then decreased with the TiO2.This tendency was influenced by the weight fraction of Al2O3 in the spraying powders and the cooling rate of splats during spraying.