Research On Mechanism Of Ultrasonic-Assisted Titanium Alloy Laser Deposition Repair

Laser deposition forming has broken the limitation of traditional remove or deformation processing forming method by the material forming ideas of discrete and accumulation. Which further the precise forming of workpiece through synchro delivery and digital laser cladding forming. However the pores, fusion defects and the problem of tasymmetrical distribution of tissue existing the process of forming which leads to the mechanical property of workpiece is not well. In view of the application of power ultrasonic in casting and welding inhibit pores and fusion defects, uniform organization successfully. We come up with the concept--?Laser cladding repairing technology assisted with ultrasonic?.First, we set up an ultrasonic vibration device to test based on the characteristics of ultrasonic vibration. Simulating and analyzing the vibration characteristics of substrate by numerical simulation software to achieve the vibration system in a state of resonance and make the energy function in laser deposition repair effectively.The change of internal pressure of molten pool under the effect of ultrasonic vibration are simulated and analysed by the dynamic mesh technology of Fluent. The distribution of the maximum dynamic pressure of the molten pool transform in a symmetric ring- shaped state and decrease gradually over a period. The method of finite element is used to deal with the analysis coupling ultrasonic field with flow field and temperature field during the process of laser melting. The influence of ultrasonic field on temperature field, flow field and the melt pool morphology during laser melting was studied through numerical simulation and experiment. The results show that the temperature of molten pool lower, the temperature gradient reduce, the velocity and the convection of flow field increase under the effect of ultrasonic field.Through the experimental study of the melt pool morphology and mechanical property of forming of ultrasonic assisted laser deposition repair titanium alloy. The results show that the energy of ultrasonic could pass into the molten pool effectively, the corrosion-resistance of fused area improve, the residual stress optimized, but the impact mechanical property reduces under the effect of ultrasonic vibration. Laying a foundation for the further research of the mechanism of ultrasonic-assisted laser deposition repair by adopting the combination of numerical simulation and experimental method.