低压等离子喷涂锰酸镧锶热控涂层性能研究

Study on Property of La_(1-x)Sr_xMnO_3 Thermal Control Coating by Low Pressure Plasma Spraying

本文采用低压等离子喷涂工艺制备了三种不同配方的La_(1-x)Sr_xMnO_3热控涂层,对La_(1-x)Sr_xMnO_3粉末及涂层的性能进行了研究,研究结果表明:采用低压等离子喷涂工艺制备的La_(1-x)Sr_xMnO_3涂层,涂层结构较为致密,La_(1-x)Sr_xMnO_3粉末形成涂层后La、Sr、Mn元素含量发生变化,随着Sr掺杂量的增大,涂层中的La、Sr元素相对含量明显提升,Mn元素含量大幅下降,涂层中的La_(1-x)Sr_xMnO_3钙钛矿相出现明显的分解现象。通过对La_(1-x)Sr_xMnO_3涂层进行-100℃^+100℃变温发射率性能测试,La_(0.8)Sr_(0.2)MnO_3粉末喷涂制备的热控涂层具有较为优异的变温发射率,发射率变化量为0.39。

In this paper, three kinds of La_(1-x)Sr_xMnO_3 thermal control coatings were prepared by low pressure plasma spraying. The properties of La_(1-x)Sr_xMnO_3 powders and coatings were studied. The results show that the structure of La_(1-x)Sr_xMnO_3 coatings prepared by the low pressure plasma spraying process were dense, the contents of La, Sr and Mn of La_(1-x)Sr_xMnO_3 coatings were changed compared with the La_(1-x)Sr_xMnO_3 powders. With the amount of Sr doping increased, the contents of La and Sr in the coating layer were obviously increased, and the contents of Mn element were greatly decreased. The La_(1-x)Sr_xMnO_3 perovskite phase of the coating was obviously decomposed. The thermal control coating prepared by La_(0.8)Sr_(0.2)MnO_3 powder had excellent temperature-emissivity performance, and the thermal radiation change rate(-100℃~ +100℃) was 0.39.