| The laser rapid manufacturing of titanium alloy is one of the important researchdirections of laser metallic rapid prototyping technology at home and abroad. However, thecracks and internal quality problems of titanium alloy forming parts have restricted itsapplication in aviation and aerospace industry, energy industry, chemical industry and otherfields. In order to solve the above problems with a low cost and simple way , the ultrasonicvibration used in the laser rapid manufacturing in this paper.By borrowing the ultrasonic vibration applications in casting, welding and laser cladding,this article demonstrates the feasibility that the ultrasonic vibration can be also used in laserrapid manufacturing of titanium alloy. And improvememts of the original processingequipment in the test process are made.Investigation on the laser rapid manufacturing with ultrasonic vibration has been done.Pointed that the effective time of ultrasonic vibration was indirect decided by the laserprocessing parameters; and calibrated the ultrasonic vibration affect on the original processparameters. On this basis, produced a lot of TC4 specimens and the functional gradientmaterials containing Cr3C2 specimens, and measured the temperature of the forming process.Observed the internal quality of the forming parts, and took some mechanical propertiesexperiments.The results show that ultrasonic vibration can reduce the gas hole’s total and size; andcan refine the structure of the cladding to some extent, and make the TiC structure morehomogeneous of the functional gradient materials parts. Secondly, the grain refined andstructure homogeneous that made the hardness distribution and the wear resistance morestable of the functional gradient materials parts. Finally, the residual stress was reduced by theultrasonic vibration, and this is good for restraining the cracks and deformation, this is mainlydue to the ultrasonic vibration promoted the thermal convection of the pool, so that the temperature gradient was decreased, and the thermal stress was reduced; in addition to thegrain refined, eliminated the interdendritic tensile stress; the structure homogeneous, reducedthe shrinkage stress between different materials. |
