钛合金表面Cr2O3颗粒增强复合搪瓷涂层的抗高温氧化性能研究

Research on High Temperature Oxidation Resistance of CrO Particle Reinforced Enamel Coatings on TC4 Alloy Surface

通过在TC4钛合金的搪瓷涂层釉料中添加0%~50%的Cr2O3陶瓷颗粒,制备出了搪瓷涂层。利用XRD、EDS、SEM和体视显微镜观察搪瓷涂层的微观结构、界面形貌及相组成。结果表明:随着涂层中Cr2O3陶瓷颗粒加入量的增加,搪瓷涂层的致密度增加,但添加量超过30%以后,涂层变得疏松,涂层中添加20%~30%的Cr2O3陶瓷颗粒,其致密性最好;不含Cr2O3陶瓷颗粒的涂层组织主要由玻璃相和少量的点状晶体组成,当添加Cr2O3陶瓷颗粒的量小于30%时,晶体呈点状弥散分布;当Cr2O3含量大于30%时,晶体呈树枝状分布;搪瓷涂层中主晶相为NaAlSi3O8和Ca2SiO4,加入的Cr2O3陶瓷颗粒部分以独立相存在,部分形成Ca5Cr3O12相;添加30%Cr2O3陶瓷颗粒的搪瓷涂层抗高温氧化性能最好,这主要是因为NaAlSi3O8转变为Na2Si2O5,有利于涂层的自愈合。

By adding 0% to 50% Cr2O3 ceramic particles in the enamel of TC4 titanium alloy coating, the enamel coating was produced. The microstructure, interface morphology and phase composition of enamel coating were observed by XRD,EDS and SEM stereoscopic microscope. The results indicate that the density of enamel coating increases with the increase of the addition of Cr2O3 ceramic particles in the coating, but the coating becomes loose when the adding content is more than30%, and the compactness of the coating with 20% to 30% Cr2O3 ceramic particles is best. The structure is mainly composed of glass phase and a small amount of dot crystal when the coating has no Cr2O3 ceramic particles, and when the added Cr2O3 ceramic particle is less than 30%, the crystal is dispersively distributed in dot. However, the crystal is dendrite when the content of Cr2O3 is more than 30%. The main crystal phase of the enamel coating is NaAlSi3 O8 and Ca2SiO4, and part of the adding Cr2O3 ceramic particles exists as independent phases and part forms Ca5Cr3O12 phase. The high temperature oxidation resistance is best when 30% Cr2O3 ceramic particle is added in the enamel coating, this is because of the main crystalline phase changes from NaAlSi3O8 to Na2Si2O5,which is beneficial for self healing of the coatings.