钛基梯度功能涂层磨损和腐蚀行为研究

为开发在超高温、大温差条件下具有热应力缓和功能的新型耐磨耐蚀涂层,在钛合金表面Nd∶YAG激光制备了梯度功能涂层,SEM观察了微观组织结构,XRD分析相组成并测定了摩擦磨损和耐腐蚀性能。结果表明原位自反应生成的TiC球状增强体弥散均匀分布在FGL中,微观组织为粗大和不完整的树枝晶、相对较细小的等轴和近等轴晶及细小短纤维状形态。FGL和N-FGM耐磨、耐蚀性能优异;摩擦系数和磨损率显著降低,其平均值是Ti600基体的0.3～0.5倍;腐蚀电流和电阻值分别为Ti600的0.72和1.31倍。

Wear and corrosion behavior of Ti-matrix functional gradient layer

To improve the wear and corrosion resistance of Ti600,and alleviate thermal stress as well under hyperthermal and excessive temperature difference condition,the experiments of Ti-matrix FGL on Ti600 substrate by pulsed Nd∶YAG had been carried out.The microstructures and phase composition of the FGL were investigated.The friction wear and corrosion properties of the FGL,N-FGM and Ti600 substrate were examined.It was found that a rapidly solidified microstructure consisting of in situ synthesized TiC reinforced phase distributed on FGL substance evenly and dispersely in the form of globular grains had three main different shapes:bulky or imperfect arborescent crystal,fine or approximately equiaxial crystal and chopped fibriform crystal.The wear and corrosion resistance of the FGL was improved.Friction coefficient and wear rate decreased significantly,the value was 0.3-0.5 times of Ti600 substrate.Corrosion current and resistance were 0.72 and 1.31 times of Ti600 substrate separately.