等离子喷涂NiAl/Al<sub>2</sub>O<sub>3</sub>梯度陶瓷涂层的结构与组织特征

等离子喷涂NiAl/Al₂O₃梯度陶瓷涂层的结构与组织特征

摘要: 利用等离子喷涂方法制备了NiAl/Al2O3梯度陶瓷涂层,并对涂层的组织分布、相结构、硬度和孔隙率进行了研究.结果表明：梯度涂层的组织表现出宏观不均匀性和微观连续性的分布特征,是由α-Al2O3、γ-Al2O3、δ-Al2O3、Ni、NiO以及镍铝金属间化合物等多种相组成的复合材料;梯度涂层中NiAl合金层的孔隙最少,表面纯陶瓷层孔隙率最高;随着Al2O3含量的增加,涂层的硬度逐渐增大.

Abstract: NiAl/Al2O3 gradient ceramic coatings were fabricated by plasma spraying.The microstructure and phase structure of gradient coatings were analyzed,the hardness and porosity were tested.The gradient coatings showed the characteristic that structure was nonuniform macroscopically but consecutive microscopically.The gradient coating was multi-phase composite including α-Al2O3,γ-Al2O3,δ-Al2O3,Ni,NiO,TiO2 and Ni-Al intermetallic compound.The porosity of NiAl layer was the least and Al2O3 layer was the most,and the hardness of coating increased as the Al2O3 increased.