超音速等离子喷涂La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)透氧膜的制备与致密性研究

Research of preparation and densification of La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ) oxygen permeation membrane by supersonic plasma spraying

采用超音速等离子喷涂系统制备钙钛矿型La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)透氧膜,研究了喷距、丙烷流量和线速度主要工艺参数对透氧膜膜层结构的影响.结果表明,在喷距210mm、丙烷流量高于2.5L/min、线速度30m/min的条件下可获得结构致密、内应力水平低且无纵向裂纹的膜层.采用此优化工艺,制备了由多孔316L支撑的片式膜,该膜两侧压差达到0.12 MPa时,仍能保证氦气不通过,致密性较高.同时,制备了一种大尺寸、高透氧面积和机械强度的管式膜,对解决当前透氧膜应用所面临的强度低、不易高温密封等问题有积极意义.

The perovskite type La0.6Sr0.4Co0.2Fe0.8O3.5 oxygen permeation membrane was prepared by supersonic plasma spraying system. The influence of the main process parameters such as spray distance, propane flow rate and linear velocity on the structure of the oxygen permeation membrane was studied. The results show that the membrane with dense structure and low internal stress and no longitudial crack can be obtained under the conditions of distance of 210 mm, propane flow of 2.5L/min and line speed of 30 m/rain. Using this optimized process, a disk membrane supported by porous 316L was prepared. When the pressure difference on both sides of the membrane reached 0. 12 MPa, helium could not be passed and the degree of compactness was higher. Meanwhile, a tubular membrane with large size, high oxygen permeability area and mechanical strength was prepared, which has a positive significance to solve the current application of oxygen transport membrane facing low strength, not easy to high temperature sealing and other issues.