高能微弧火花沉积TiCrNiVSix多主元合金/氮化物复合涂层的研究

The increasing application of titanium alloy in high thrust-weight ratio engines run a risk of ignition and combustion, which promoting the application and development of burn-resistant coating on titanium alloys. In this project, multi-principal alloy/nitrides composite coatings are prepared on Ti alloy by computer numerical controlled (CNC) high energy micro-arc spark deposition. The relationship between alloy composition, phase composition, deposition parameters and the strength and toughness of the spark deposited coating are investigated. The characteristics of coating alloying and phase structure under the condition of non-equilibrium solidification spark deposition are obtained. The synthesis mechanism of nitrides which formed by in-situ reaction between the multi-principal alloy and active nitrogen that ionized from nitrogen by high energy micro-arc spark discharge is revealed. The oxidation behavior, wear behavior and burn-resistant performance of the composite coatings at high temperature are tested. This work will provide new theory gist and an effective way to protect the engine titanium alloy component from ignition and combustion. It can also play an active role in promoting the development and application of multi-principal alloy.

随着高推重比先进发动机对钛合金需求量提高与钛火倾向性增大之间矛盾的凸显，钛合金表面阻燃防护涂层需求日渐迫切。本项目采用CNC数控高能微弧火花沉积方法，在钛合金表面开展多主元合金/氮化复合涂层制备，探究多主元合金成分、涂层相组成与沉积参数及涂层强韧性之间的关系，获得火花沉积非平衡凝固条件下涂层合金化及相组织特征规律，揭示纯氮气氛环境高能微弧火花放电过程活性氮组分与多主元合金原位反应生成氮化物机制，探究复合涂层高温氧化行为、磨损行为与阻燃特性及影响机制。本研究可为航空发动机钛合金结构的表面阻燃防护提供新的理论依据和新的有效技术途径，也可对多主元合金的发展和应用起到积极的推动作用。

针对航空发动机等领域钛合金部件耐磨损、抗氧化及阻燃等表面防护需求，本项目开发了Ti-Cr-Ni-V-Si、Co-Cr-Fe-Ni-Nb-Si、Co-Cr-Fe-Ni-Mo-Si三种C14型Laves+固溶体（BCC/FCC）合金涂层体系；建立了可控气氛环境的CNC数控电火花沉积装置实现了涂层数控自动沉积，并通过多目标优化制备了高质量沉积的多主元合金涂层；放电产生的高温和电离气氛为氮化物原位形成提供了条件，在氮气气氛下通过电火花沉积、磁控溅射两种方法反应沉积获得TiCrNiVSi0.1/氮化物复合涂层；多主元合金涂层高温下可形成致密复合氧化层，Si的添加可以提升Laves相的稳定性进而提升抗氧化能力；涂层中硬质Laves相可减少粘着磨损的发生，有利于形成三体磨损，涂层室温及400℃下磨损速率仅钛合金基体的1/5；激光点燃试验中沉积多主元合金涂层后燃烧坑深度为TC4基材表面的1/3，表面反应沉积制备的氮化物可进一步提升阻燃性能。本项目可为航空发动机等钛合金部件的表面防护提供参考，也可对多主元合金的高温应用起到积极的推动作用。