Study On Microstructure And Properties Of 2A12 Aluminum Alloy Made By High Frequency Vibration Compound Arc Additive

Wire and Arc Additive Manufacturing(WAAM)technology has the advantages of high sample density,low equipment cost,high forming efficiency,and the ability to form large-sized structural workpieces.It has broad applications in aerospace,weaponry and other fields prospect.However,there are problems such as low welding bead adhesion between workpiece layers and serious bubble tendency.This article introduces a high-frequency vibration process on the basis of the arc additive manufacturing process,and develops a composite manufacturing process to enhance the heat dissipation of the deposited layer to achieve the effect of controlling the number and area ofbubbles,suppressing thermal cracks and refining grains,thereby improving the workpiece The overall performance;research and development of thermal vibration composite technology to improve the degree of homogenization,so that the residual stress within the workpiece is reduced or even eliminated.First of all,the vibrometer and the substrate used in the experiment were connected by a double-ended threaded rod,and real-time contact-type high-frequency vibration was applied to the substrate while forming the workpiece.The experimental results show that the performance of each region of the workpiece increases with the increase of high-frequency power,and the increasing-decreasing-increasing change curve is formed with the increase of high-frequency frequency.Within the range of adjustable parameters of the equipment,the high-frequency vibration power is 20 W.At a frequency of 996 Hz,the tensile strength of the workpiece formed by the composite manufacturing process is the best.The average tensile strength of the workpiece has reached 247.56Rm/MPa,which is 36.07% higher than that of the arc-additive manufacturing.Secondly,the influence of the thermal vibration composite process on the residual stress in the workpiece is studied.Data analysis found that the residual stress in the X and Y directions of the workpiece after the heat treatment is generally larger,and the Y direction is almost above 100 MPa,and the stress concentration is particularly obvious;after the thermal vibration composite process,the residual stress values in the X and Y directions of the workpiece are both In the range of ± 50 MPa,the overall residual stress value is low,and the effect of stress homogenization is very obvious.Finally,the thin-walled rotating frame workpieces with small,medium,complex,and multi-structural features among the components required in the aerospace field are selected to verify and analyze the practical application of the composite manufacturing process and composite processing process.Observation shows that the rotating frame formed by the composite manufacturing process does not have large defects after the thermal vibration composite process and milling.There are no cracks,deformation and collapse areas on the surface.The overall forming effect is good and the accuracy is high,which is consistent with the ideal process measurement.Effect of stress equalization.