过渡层结构设计对钛合金表面DLC薄膜影响机制及其在航空花键应用验证
王宇琦¹，周亚强¹，王广飞¹，刘兴光¹，郑军^1，*
1安徽工业大学 材料科学与工程学院， 安徽 马鞍山，243000
教育部重点实验室
摘要：针对钛合金传动部件中耐磨薄膜与基体界面结合强度不足制约其服役寿命的关键问题，本研究通过多尺度界面设计，采用磁控溅射技术在Ti6Al4V（TC4）表面构筑了具有不同过渡层（Ti、Ti/TiN、Ti/TiC、Ti/TiN/TiC）的类金刚石碳基（DLC）薄膜。采用扫描电子显微镜（SEM）、纳米压痕及划痕测试揭示了过渡层构型对薄膜微观结构演变和界面力学行为的影响机制，结合摩擦磨损测试与扭转疲劳实验评估了薄膜体系在航空花键副上的工程适用性。研究表明：（1）梯度化过渡层设计通过协调界面热膨胀系数失配，使Ti/TiN/TiC体系的膜基结合力达280 mN，较单层Ti结构提升30 %；（2）多层过渡结构促使DLC薄膜形成致密sp³杂化网络，其摩擦系数稳定于0.15 ± 0.01，磨损率降低至(1.2 ± 0.1)×10⁻¹⁶ m³/ ( N·m )量级；（3）镀膜花键副的扭转疲劳寿命提升至钛合金基体的2.8倍，失效分析表明其损伤机制呈现粘着磨损-磨粒磨损-氧化磨损协同作用。本研究为航空钛合金传动部件的表面强化提供了理论依据与应用解决方案。
关键词：钛合金花键；过渡层；类金刚石薄膜；磨损机理；疲劳性能
Abstract: In order to solve the key problem of insufficient adhesion strength between the wear-resistant film and the substrate interface in titanium alloy transmission components, which restricts their service life, this study constructed diamond-like carbon (DLC) films with different interlayers (Ti, Ti/TiN, Ti/TiC, Ti/TiN/TiC) on the surface of Ti6Al4V (TC4) using magnetron sputtering technology through multi-scale interface design. The influence mechanism of the interlayer configuration on the microstructural evolution and interfacial mechanical behavior of the film was revealed using scanning electron-microscopy (SEM), nanoindentation, and nano-scratch tester. The engineering applicability of the film system on the aerospace spline pair was evaluated by combining friction and wear testing with torsional fatigue experiments. The results show that: (1) The gradient interlayer design can coordinate the mismatch of thermal expansion coefficients at the interface, resulting in a film-substrate adhesion strength of 280 mN for the Ti/TiN/TiC system, which is 30% higher than that of the single-layer Ti structure; (2) The multi-layer transition structure promotes the formation of a dense sp³ hybrid network in the DLC film, resulting in a stable friction coefficient of 0.15 ± 0.01 and a reduced wear rate of (1.2 ± 0.1) × 10⁻¹⁶ m³/(N·m); (3) The torsional fatigue life of the coated spline pair is increased to 2.8 times that of the titanium alloy substrate. Failure analysis indicates that the damage mechanism exhibits a synergistic effect of adhesive wear, abrasive wear, and oxidative wear. This study provides a theoretical basis and application solution for surface strengthening of aviation titanium alloy transmission components.
Keywords: Titanium alloy spline; interlayer; diamond-like carbon films; wear mechanisms; fatigue performance.
 

钛合金花键；过渡层；类金刚石薄膜；磨损机理；疲劳性能