目的 研究冷喷涂TC4涂层的临界沉积速度及粒子温度对临界沉积速度的影响规律，并研究气体压强对沉积涂层性能的影响规律。方法 理论研究上，采用有限元LS-DYNA软件中的Johnson-Cook塑性模型，选取3D164计算单元建立模型，研究粒子在不同温度和不同速度下碰撞基体后的形貌特征，确定粒子沉积临界速度。试验研究上，采用N2作为冷喷涂驱动气体，在TC4合金上制备TC4涂层，然后采用SEM、Image J图像分析软件、硬度计等分析已沉积涂层的孔隙率和硬度等性能。结果 25、400、500、600 ℃温度下，计算表明10 μm的TC4合金粒子在TC4基板上的临界沉积速度分别为730、465、392、361 m/s，即随粒子温度升高，粒子临界沉积速度降低，粒子沉积成涂层更容易。采用冷喷涂工艺在TC4基板上沉积TC4涂层，在N2温度600 ℃、气体压力3 MPa的条件下，制备的TC4涂层厚度约1000 μm，与TC4钛合金基体结合紧密，涂层孔隙率约为6.46%。结论 气体温度升高，粒子临界沉积速度降低；气体压强变大，制备的涂层厚度就大且更加致密。

The work aims to study rule of effects of critical deposition velocity of cold spray TC4 coating and particle temperature on critical deposition velocity, and also rule of effects of gas pressure on properties of deposition coating. Theoretically, Johnson-Cook model and 3D164 model in LS-DYNA software were used to study morphology characteristics of particles colliding with the substrate at different temperature and velocity, and then determine threshold deposition velocity. Experimentally, N2 as cold spray driving gas was adopted to prepare TC4 coatings on TC4 substrate. Then, SEM, Image J image analysis software, sclerometer and other methods were used to measure porosity and hardness of the coatings. Threshold deposition velocity of D=10 μm TC4 powder was 730, 465, 392 and 361 m/s at 25, 400, 500, 600 ℃, respectively, indicating that threshold deposition velocity decreased and particles could be deposited easily into coatings as powder temperature increased. TC4 coatings deposited on TC4 baseplate by adopting cold spraying technique exhibited stronger adhesion to TC4 substrate, thickness was nearly 1000 μm and porosity was nearly 6.46% provided with N2 temperature of 600 ℃ and gas pressure of 3 MPa. Threshold deposition velocity decreases as gas temperature increases; both thickness and density of the coatings prepared increase as gas pressure increases.