Ultrasonic liquid knife impacting metal material surface nanocrystallization method and special device thereof

Abstract

The invention relates to the field of metal material surface nanocrystallization, in particular to an ultrasonic liquid knife impacting metal material surface nanocrystallization method and a specialdevice thereof. According to the method, a high-pressure liquid is adopted to carry high-energy ultrasonic waves, and the surface of a metal material is impacted through a liquid knife nozzle. The method comprises the following steps: 1, matrix pretreatment, specifically, carrying out conventional surface polishing and cleaning by using acetone and alcohol; and 2, surface nanocrystallization, specifically, adopting the high-pressure liquid to carry the ultrasonic energy waves and move at a high speed to impact the surface of the metal material. The device comprises a liquid knife device and anultrasonic generating device, wherein the ultrasonic generating device comprises an ultrasonic generator, an ultrasonic horn and an ultrasonic transducer; and the liquid knife device comprises a liquid knife liquid inlet pipe, an impact liquid tank, a liquid knife nozzle and a liquid knife pressurizing tank. According to the method and the device, through the processing method for generating plastic deformation on the surface layer of the material, the grain size of the surface layer of the material is formed into a structure sequentially comprising nano-sized grains, submicron-sized grains,deformed grains and initial grains from the surface to the inside.

Description

technical field [0001] The invention relates to the field of nanometerization of the surface of metal materials, in particular to a method for nanometerization of the surface of metal materials impacted by an ultrasonic liquid knife and a special device thereof. Background technique [0002] At present, the methods for forming gradient structures on the surface of shaft-like metal materials mainly include: [0003] ① Surface mechanical grinding treatment method [0004] The surface mechanical grinding treatment method is to hit the surface of the material being treated by a high-speed moving projectile, resulting in strong plastic deformation on the surface of the material and introducing a large number of defects, such as dislocations, twins, shear bands, etc. When the dislocation density is large enough When dislocation annihilation and recombination occur, nano-sized grains are formed, and the grain size gradually increases along the thickness direction of the gradient s...

AI Technical Summary

Problems solved by technology

Disadvantages: the surface roughness of the processed material is large, and the processing efficiency is low

Disadvantages: The advantage of rolling technology is to improve the surface finish of the workpiece. As for the improvement of surface hardness and fatigue performance, there is a limit, because rolling technology is impossible to form a nanocrystalline structure on the surface of the workpiece, or even a submicron structure.

Disadvantages: The surface finish of the workpiece after processing is still not good enough, the processing efficiency is low, there are high requirements for the shape and size of the workpiece, it is difficult to process complex workpieces, the processing temperature is high, a complex cooling system is required, and the processing energy consumption is high

Disadvantages: low processing efficiency, high requirements for workpiece dimensions, difficult to process complex workpieces, high processing temperature, complex cooling system is required, high energy consumption for processing

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