钛合金表面半导体激光气体氮化涂层的性能研究

Properties of Diode Laser Gas Nitriding Coatings on the Surface of Titanium Alloy

目的提升钛合金(TC4)叶片表面性能,解决失效问题。方法实验采用激光局部气体氮化工艺代替传统氮化工艺,利用2 k W柔性光纤耦合半导体激光器在钛合金(TC4)基体表面采用气体氮化的方法制备TiN表面改性层。采用摩擦磨损试验机和改制的汽蚀装置分别测试了氮化层与基体(TC4)的耐磨性与抗汽蚀性能。结果摩擦磨损实验后,激光氮化层的质量损失为2.3 mg,基体TC4的质量损失为20.2 mg,激光氮化层的损失质量为基体TC4的11.3%,激光氮化层抗磨损性能相较基体TC4提高了7倍。TC4基体汽蚀损失的质量为4.08 mg,而氮化层的质量损失为1.13 mg,氮化层的抗汽蚀性能比基体提高了2.61倍。结论采用半导体激光气体氮化钛合金叶片能够得到分布着大量TiN枝晶的氮化层,提高表面耐磨损性能,氮化层中的TiN枝晶构成的网篮状组织对其表面抗汽蚀性能也有所提高。

Objective In order to enhance the surface properties of titanium alloy （TC4） blade and solve the failure problem.Methods With laser gas nitriding technology instead of traditional nit＇riding technology, TiN surface modification layer was prepared on the surface of titanium alloy （TC4） with a 2 kW flexible fiber coupled diode laser. The wear-resistant property and anti-cavitation property of the nitriding layer and the substrate （TC4） were examined by the friction-abrasion testing machine and modified experimental device for cavitation erosion. Results The results showed that the wear loss weight of TC4 substrate was 20.2 mg while that of nitriding layer was 2.3 mg, which was only 11.3% of TC4 substrate, The wear resistance increased by 7 times compared with that of the TC4 substrate. The cavitation erosion loss weight of TC4 substrate was 4.08 mg while that of nitriding layer was 1.13 nag. The anti-cavitation property increased by 2.61 times compared with that of the TC4 substrate. Conclusion A large number of TiN dendrites in the nitride layer can be obtained with diode laser by laser gas nitriding titanium alloy blade, which improves wear-resistant property of the surface. The distribution of the basket shaped structure of TiN dendritic crystal improves the anti-cavitation property of the surface.