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采用大气等离子喷涂(APS)在高温合金表面制备一层Ni Co Cr Al Y粘结层,然后采用阴极等离子电解沉积(CPED)制备一层弥散Pt微粒的8YSZ涂层。通过在电解液中加入陶瓷微珠,促使阴极表面发生均匀的等离子微弧放电,实现了在大面积样品上沉积8YSZ涂层。获得的涂层厚度到达120μm,具有多孔结构,由立方相和四方相8YSZ以及Pt组成。1100℃空气中循环氧化的结果表明,随着涂层中Pt含量的的增加,涂层的抗高温氧化和抗剥落性能得到明显提高。Pt微粒对8YSZ涂层的增韧作用主要为:Pt微粒塑性变形吸收裂纹扩展的能量,钝化裂纹尖端,减小裂纹尺寸,提高涂层的临界断裂应力。
An Ni Co Cr Al Y bonding layer was prepared on the superalloy surface by atmospheric plasma spraying (APS), and then a 8YSZ coating of dispersed Pt particles was prepared by cathodic plasma electrolytic deposition (CPED). By adding ceramic microbeads into the electrolyte to promote uniform plasma microarc discharge on the cathode surface, 8YSZ coating can be deposited on large area samples. The resulting coating reached a thickness of 120 μm and had a porous structure consisting of cubic and tetragonal phases 8YSZ and Pt. The results of cyclic oxidation at 1100 ℃ in the air show that with the increase of Pt content in the coating, the high temperature oxidation resistance and spalling resistance of the coating are obviously improved. The main toughening effect of Pt particles on 8YSZ coating is that the plastic deformation of Pt particles absorbs the energy of crack propagation, passivates the crack tip, reduces the size of cracks and increases the critical fracture stress of the coating.