Jiangsu University

Xiankai Meng

Jianzhong Zhou

Shu Huang

Pengfei Li

Yanqiang Gou

Li Li

Jinzhong Lu

Jie Sheng

Lei Huang

Hansong Chen

Yu Zhang

Chun Su

Fengze Dai

Jing Li

Qi Sun

Jianian Yang

Xu Feng

Qiang Fu

Hongda Zhou

Yaomin Zhao

Jie Cai

Xiangwei Yang

Yanhu Zhang

Xv Feng

Gaoqiang Jiang

Songling Chen

Hongxu Pu

Ling Dai

Jiale Xu

Kun Huo

Junling Wu

Hongmei Zhang

The present disclosure provides a high-pressure and multi-atmosphere assisted SLM gradient material preparation method and an aluminum-lithium alloy coating. The high-pressure and multi-atmosphere assisted SLM gradient material preparation method includes the following steps: injecting a first gas mixture into a working box, and enabling, by laser irradiation, molten materials in a micro-melt pool to react with a carbon-containing gas to form a carbide-doped first gradient aluminum-lithium alloy coating; injecting a second gas mixture into the working box, and enabling, by laser irradiation, molten materials in a micro-melt pool to react with a carbon and nitrogen-containing gas to form a carbide and nitride-doped second gradient aluminum-lithium alloy coating; and injecting a third gas mixture into the working box, and enabling, by laser irradiation, molten materials in a micro-melt pool to react with a nitrogen-containing gas to form a nitride-doped third gradient aluminum-lithium alloy coating. The present disclosure improves the surface forming quality of an aluminum-lithium alloy material, and the material is hard outside and tough inside.

High-pressure and multi-atmosphere assisted SLM gradient material preparation method and aluminum-lithium alloy coating

A method for shape-performance control by ultrasonic rolling combined with selective laser melting is provided, which includes following steps: S1, establishing a three-dimensional model of a component to be processed, and setting printing process parameters; S2, after nitrogen gas is filled into a forming cavity to reduce an oxygen content to a preset value, lowering a forming substrate and raising a powder substrate, laying powder from the powder substrate onto the forming substrate by a scraper, recovering excess powder, and after the laying is completed, melting the powder by a laser galvanometer to form a solid layer, and cycling for several times; S3, performing ultrasonic rolling on a surface of the solid layer; S4, cycling steps S2 and S3 until the component is formed, and ending the cycling; and S5, performing ultrasonic rolling on a surface of a formed component to obtain a solid component.

Method and device for shape-performance control by ultrasonic rolling combined with selective laser melting

The present disclosure provides a method for preparing a superhydrophobic surface of an aluminum alloy through laser peening, including the following steps: coating a surface of the aluminum alloy as an absorption layer with an organic component-containing confinement layer to obtain a coated aluminum alloy, where the organic component-containing confinement layer is a mixed organic solution including 5 mL to 10 mL of perfluorooctyltriethoxysilane (FOTS), 100 mL to 200 mL of absolute ethanol, and 30 mL to 50 mL of distilled water; and subjecting a surface of the coated aluminum alloy to the laser peening to form the superhydrophobic surface.

Method for preparing superhydrophobic surface of aluminum alloy through laser peening

A stress and texture morphology controlling method for preparing a super-hydrophobic surface of an aluminum alloy by laser etching includes the following steps: pretreating a surface of an aluminum alloy; fixing a pretreated aluminum alloy to an ultrasonic vibration platform, continuously charging flowing liquid nitrogen to a to-be-machined surface of the aluminum alloy, and controlling a flow of the liquid nitrogen to cool the to-be-machined surface of the aluminum alloy and keep the to-be-machined surface of the aluminum alloy at a low temperature; keeping stable flowing of the liquid nitrogen on the to-be-machined surface of the aluminum alloy after the to-be-machined surface of the aluminum alloy is cooled, using the ultrasonic vibration platform to generate a high-frequency ultrasonic vibration field, and etching the to-be-machined surface of the aluminum alloy to form a super-hydrophobic textured micro-nano structure surface; and reducing a surface energy of the super-hydrophobic textured micro-nano structure surface.

Stress and texture morphology controlling method for preparing super-hydrophobic surface of aluminum alloy by laser etching

A method for preparing a super-hydrophobic aluminum alloy surface through flat-topped laser peening includes the following steps: pretreating an aluminum alloy surface; evenly coating the pretreated aluminum alloy surface with a nanoscale carbon powder layer; performing unconstrained peening treatment on the aluminum alloy surface using a square spot flat-topped nanosecond pulsed laser with the nanoscale carbon powder layer serving as an absorption layer, where beams are kept perpendicular to the aluminum alloy surface all the time; and removing residual carbon nanopowder after the peening, and reducing surface energy of the aluminum alloy material through low-temperature heat treatment, to obtain a super-hydrophobic aluminum alloy surface with micro-nano multiscale structures. According to the present disclosure, the carbon content near the surface layer of the aluminum alloy material is increased, and the hardness and wear resistance of the prepared hydrophobic surface can be effectively improved.

Method for preparing super-hydrophobic aluminum alloy surface through flat-topped laser peening

A pulse current-assisted laser peen forming and hydrophobic surface preparing method for an aluminum alloy includes the following steps: placing a pretreated aluminum alloy onto a shock platform, where electrodes are respectively provided at two ends of the aluminum alloy, and flowing silicone oil covers a surface of the aluminum alloy; determining a laser energy; applying a high-frequency pulse current to the surface of the aluminum alloy through the electrodes, where a shot peening laser generates a laser beam according to the laser energy to shock the surface of the aluminum alloy, and under an action of an electrical pulse and laser shock, the aluminum alloy shows a bent arc-shaped surface, with a shock surface forming a porous micro-nano multi-stage surface; and performing chemical modification on the shock surface of the aluminum alloy to reduce a surface energy of the material, thereby obtaining a super-hydrophobic arc-shaped aluminum alloy surface.

Pulse current-assisted laser peen forming and hydrophobic surface preparing method for aluminum alloy

The present invention provides a device for peening by coupling a laser shock wave and an ultrasonic shock wave in real time. The device includes a synchronization device, a laser device, two ultrasonic shock devices, a working platform and a control system. An upper casing is supported above a base through second hydraulic cylinders. Two supporting beams are provided under the upper casing through the second hydraulic cylinders. Limiting slide rails are provided under the upper casing through first hydraulic cylinders. The two ultrasonic shock devices are connected through the synchronization device, which is configured to synchronize movement and rotation of the two ultrasonic shock devices. The laser device is configured to generate a laser beam to pass through the upper casing and irradiate a surface of a workpiece. The control system controls the laser device to lag behind the two ultrasonic shock devices to perform laser shock.

Laser processing device and method for peening

The present disclosure provides a numerical simulation method of pulsed laser paint removal and a use thereof. This method establishes a three-dimensional (3D) temperature field model by ANSYS software to perform a numerical simulation of nanosecond pulsed laser paint removal. A high-speed moving pulsed laser is loaded on a surface of the model in a form of heat flux, and a coordinate system is moved to realize loading on different paths. A special surface mesh screening method is used to realize loading on any surface, and it ensures that laser energy distribution on a material surface is in line with reality. In addition, an element birth/death technology is combined to remove an element that exceeds a threshold, so as to intuitively present the surface morphology after laser paint removal. The present disclosure can realize the prediction of the contour of a paint layer ablated by a pulsed laser.

Numerical simulation method of pulsed laser paint removal and use thereof

In a cryogenic workbench, a cryogenic laser peening system and a control method, a tapered surface gap d is adjusted, based on the electromagnetic principle, to control the gasification volume of liquid nitrogen, then the temperatures of the copious cooling workbench and the surface of a sample are precisely controlled by means of the adjustment of the heat absorption amount of liquid nitrogen gasification, the temperature adjustment range and the temperature rising/lowering rate of the cryogenic laser peening system are effectively extended, and the precision of the control of the surface temperature of the sample is increased in combination with a closed-loop control. Additionally, an intelligent control of a cryogenic laser peening process is realized by means of a computer and a PLC control unit, whereby the usage amount of liquid nitrogen in the experiment process is reduced and the processing efficiency is improved.

Cryogenic workbench, cryogenic laser peening experiment system and control method therefor

An electromagnetic apparatus for active intervention to a shape of a molten pool is provided. In the present invention, a workpiece is placed on stepped surfaces of a test bench. Upon power on, a metal rod rotates to generate a toroidal magnetic field centered on the metal rod, and the toroidal magnetic field acts on the molten pool to generate an induced current. The induced current generates Lorentz force under the action of the magnetic field, which acts perpendicularly on an outer surface of the molten pool, thereby changing the height, depth and width of the molten pool, and finally realizing the active intervention to the molten pool shape.

Electromagnetic apparatus for active intervention to shape of molten pool

A method and a device for increasing a laser induced shock wave pressure. According to the method, plasmas () are generated by impinging an aluminium foil () using lasers; a high-voltage pulse electrode () discharges to the plasmas () to induce and form a photoelectric combined energy field and then high-temperature plasmas () having the characteristics of an ultra-high density and an ultra-high speed expansion are induced and generated; a surface to be processed is impacted by the high-temperature plasmas () in a restrained state; the laser induced shock wave pressure is increased substantially; the surface of a high-strength material is reinforced, and the strength, hardness, abrasion resistance and anti-fatigue performances of the high-strength material are improved. The device comprises a laser, the electrode (), a high-voltage power supply (), a discharging medium (), a moving platform, etc.

Method and device for increasing laser-induced shock wave pressure

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Jiangsu, China

Xiankai Meng