NaAlO2浓度对发动机用Ti600合金微弧氧化层组织及摩擦性的影响

Effect of NaAlO2 Concentration on Microstructures and Tribological Properties of Micro-Arc Oxidized Ti600 Alloy

为了提高发动机用Ti600合金的表面的抗氧化性,对其表面进行恒流模式微弧氧化处理,研究NaAlO2浓度对Ti600合金微弧氧化层组织及摩擦性的影响。研究结果表明:在最初的3 min时间内,电压发生了快速上升的现象,之后变的平稳。氧化层形成了许多微孔结构,在表面形成了具有不连续部分特点的氧化物。NaAlO2浓度越高生成的氧化层越均匀。试样表面生成了致密与疏松结构两种氧化膜组织,达到了良好冶金相容的效果。Ti600合金经过微弧处理可以获得良好的减摩效果,得到了具有致密组织结构的较厚微弧氧化膜,达到了更优的耐磨性。当NaAlO2浓度12 g/L时,形成疏松的氧化层,在磨损期间较易被磨损破坏,形成平整的磨痕。

The surfaces of Ti600 alloy,an advanced aircraft-engine material,were modified by micro-arc oxidization in NaAlO2 solution.The influence of the NaAlO2-concentration on the microstructures and tribological behavior was investigated with XRD,energy dispersive spectroscopy and scanning electron microscopy.The preliminary results show that the NaAlO2-concentration had a major impact.For example,the oxidation voltage increased rapidly in the 1st three minutes to the arcing voltage,at which small sparks showed-up,then,it slowly increased.As the NaAlO2-concentration increased from 0.0 to 10 g/L,the arcing voltage and friction-coefficient decreased,the hardness and thickness increased,but the wear-rate changed in an increase-decrease manner;and the irregularly-shape porous oxides islands grew into continuous uniform coatings.Though the porous surface layer was rather loose,the compact interfacial layer exhibited strong adhesion.Formed at a NaAlO2-concentration of 12 g/L,the fairly loose/porous oxides surfaces displayed a rather low wear-resistance.