Equipment Development And Process Research Of Ultrasonic Metal Additive

Metal additive technology has been developed for decades,and commonly used additive technologies include laser additive and electron beam additive technologies.However,due to the limitations of technology,efficient processing and production cannot be performed in some fields.In order to alleviate technical problems,ultrasonic metal additive manufacturing technology has come out in recent years,and has attracted the attention of many researchers.However,so far,there are still different opinions on the consolidation mechanism of ultrasonic metal additive manufacturing technology,and the influence of process parameters on the performance of additive specimens has not been fully studied,which greatly limits the vigorous development of this technology.In this paper,it is hoped that through the ultrasonic metal additive test,the mechanism of metal consolidation and the influence of process parameters on the mechanical properties of the consolidated specimen can be deeply understood.The main research contents are as follows:(1)By deriving the acoustic,kinematic and static formulas,the structural design and standard part selection of the components of the ultrasonic consolidation system and other auxiliary working systems of the ultrasonic additive equipment are carried out,and the finite element modal analysis and result verification of the three-dimensional model are carried out by using ABAQUS software.Finally,the ultrasonic metal additive equipment with double transducers is developed.(2)The self-made equipment was used to carry out the ultrasonic consolidation test of the metal aluminum foil,and the metallographic microscope and scanning electron microscope were used to analyze the micro-morphology of the consolidation interface of the consolidation specimen;the temperature field test platform was built to collect the thermal transient of the temperature field in the consolidation area.Through experiments,it is found that there are three common microscopic defects in the consolidation interface,namely: linear,point-like and irregular defects;within the range of experimental parameters,the consolidation quality has a positive correlation trend with pressure and amplitude,and a negative correlation trend with speed;The thermal transient in the junction region does not exceed 150°C,which is far less than the melting point of aluminum at 600°C.(3)By comprehensively analyzing the interface micro-topography and thermal transient state,it is finally found that the frictional heat generated by the high-frequency vibration of the consolidation tool head during ultrasonic metal consolidation will cause plastic deformation,flow and atomic diffusion on the surface of the metal material,thereby achieving Ultrasonic consolidation additive of metal foil;in addition,the dense oxide film on the surface of aluminum foil will be destroyed by high-frequency vibration during ultrasonic consolidation and split into small fragments and dispersed around with the vibration,which has a limited impact on the consolidation quality.(4)Tensile test,three-point bending test,microhardness test,surface roughness test and friction and wear test were carried out on the consolidated specimen,and the effect of different process parameters on the properties of the consolidated specimen was analyzed by comparing the test results.Through experiments,it is found that within the range of experimental parameters,the increase of consolidation pressure and consolidation amplitude will effectively improve the mechanical properties of the specimen,and the increase of speed will reduce the mechanical properties of the specimen;the maximum tensile strength of the consolidated specimen can reach 89.86MPa;the maximum flexural strength of the consolidated specimen can reach 151MPa;the maximum microhardness is 33.5HV,which is much larger than the 21 HV of the raw material;the minimum surface roughness Ra can reach 2.884 μm.