可控气氛下梯度涂层组织与结合性能分析

Analysis of microstructure and binding ability of gradient coatings in controlled atmosphere

关键词:  可控气氛  等离子喷涂  氧化铝  梯度涂层  结合强度

Key words:  controlled atmosphere  plasma spraying  Al₂O₃ ceramic  gradient coatings  bond strength

摘要:

陶瓷梯度涂层的性能优良,在大气氛围下等离子喷涂制备的涂层会受到空气的氧化.针对这一情况,在可控气氛(氩)中采用等离子喷涂方法制取了Ni-Cr-B-Si/Al₂O₃的梯度涂层,与在空气中制取的Ni-Cr-B-Si/Al₂O₃梯度涂层进行了对比.分析了氩气氛围对梯度涂层显微组织和结合强度的影响.结果表明,在氩气中和空气中的梯度涂层组织内部都没有明显的界面,其组织呈连续变化;在氩气中制取的梯度涂层的组织更加致密,被氧化的程度更低,结合强度更高.

Abstract:

Because ceramic gradient coating with excellent performance will be affected by air oxidation effects in air atmosphere plasma spray coating preparation,Ni-Cr-B-Si/Al₂O₃ gradient coating is prepared in controlled atmosphere(argon) plasma spraying.The atmospheric conditions of making Ni-Cr-B-Si/Al₂O₃ gradient coatings are compared,and the effects of argon atmosphere on the microstructure and bonding strength of sprayed gradient coating are analyzed.The results show that the inside organization of gradient coating in argon atmospheres and in air has no obvious interface and achieves continuous change of microstructure,but the gradient coating organization in argon is more dense,lower oxidative and has higher bonding strength than that in air.