Jiangsu University

Southeast University

Wenzhou University

Institute of Laser and Optoelectronics Intelligent Manufacturing, Wenzhou University

Kaiyu Luo

Jinzhong Lu

Haifei Lu

Liujun Wu

Changyu Wang

Fang Wang

Xiang Xu

Yongkang Zhang

Bo Liu

Fengze Dai

Xiaohong Xu

Wei Xue

Yikai Shao

Yue Liu

Zhilong Wang

Xiancheng Zhang

Jia Xing

Guang Yang

Tong Lin

Xiang Jing

Shijie Ji

Jialong Du

Xingyu Bu

Weiwei Deng

Jianhua Yao

Yefang Yin

Yao Xue

Fangnian Lang

A method of strengthening through real-time coupling of electrical pulses and laser shock waves is provided. The initial time and duration of the electrical pulses are controlled to be matched with the initial time and duration of the laser shock waves, so that the electrical pulses and the laser shock waves are coupled in real time for material strengthening, the plasticity and the strength of the material are greatly improved, and a large area of the workpiece is uniformly strengthened. By simultaneously introducing the electrical pulses into the pulse current-assisted LSP, a great strengthening effect is achieved through the combination of the electrical pulses and the pulse current-assisted LSP in a short time, thereby reducing the internal defects of the material to a certain extent and further increasing the fatigue life of the material.

Method of strengthening through real-time coupling of electrical pulses and laser shock waves

The present disclosure relates to an eccentric extreme high-speed-rate laser hybrid manufacturing method for a rotary engineering component. By positioning an extreme high-speed-rate laser direct energy deposition machining head at a predetermined eccentric distance, the damage caused by reflected light to the machining head is effectively reduced, to prolong a service life of the machining head. Also a conventional form of a molten pool in extreme high-speed-rate laser direct energy deposition can be changed, namely from a 'falling' form caused by a high-speed movement and a gravity to a “climbing” form. Thus, in extreme high-speed-rate laser direct energy deposition machining, the molten pool has a longer time to fully contact a surface of the rotary engineering component to form desirable bonding performance.

Eccentric extreme high-speed-rate laser hybrid manufacturing method for rotary engineering component

Provided is a combined fabricating method for gradient nanostructure in the surface layer of a metal workpiece. A plastic deformation layer in great depth is induced by laser shock peening, then the surface of the metal workpiece is nanocrystallized by surface mechanical attrition treatment, and finally a gradient nanostructure is obtained in the surface layer of the metal workpiece with desirable layer thickness and optimized micro-structure distribution.

Combined fabricating method for gradient nanostructure in surface layer of metal workpiece

Disclosed is a surface modification technique for permanent magnetic materials. First, a sintered Nd&#x2014;Fe&#x2014;B magnet is immersed in a chlorine-containing solution to corrode its surface after the sintered Nd&#x2014;Fe&#x2014;B magnet is ground, polished and cleaned, so that atomic vacancies or gaps are produced at the grain boundaries in the surface layer of the corroded sintered Nd&#x2014;Fe&#x2014;B magnet; then, compound nanopowders coated on the surface of the sintered Nd&#x2014;Fe&#x2014;B magnet are implanted into the grain boundaries by laser shock peening to obtain a gradient nanostructure layer along the depth direction; at the same time, the surface nanocrystallization of the sintered Nd&#x2014;Fe&#x2014;B magnet and a residual compressive stress layer are induced by laser shock peening which remarkably improves the corrosion resistance of the sintered Nd&#x2014;Fe&#x2014;B magnet.

Laser shock peening method for improving the corrosion resistance of sintered Nd&#x2014;Fe&#x2014;B magnet

Disclosed is a combined treatment method for improving corrosion resistance of metal component in chlorine-containing solution. First, the metal component is placed in the chlorine-containing solution. Large-area overlapping laser shock peening without an absorbing layer is used, when laser pulses are irradiated on the target metal component, the metal matrix surface absorbs the laser energy, vaporizes and expands to form a high-temperature and high-pressure plasma, a chlorine-containing passivation film is formed, to improve the surface corrosion resistance of the metal component. After that, the surface layer of the metal component is subjected to surface polishing, followed by large-area overlapping laser shock peening with an absorbing layer at room temperature, to further improve the corrosion resistance of the metal component. The combined treatment method of the present invention can be applied to improve the corrosion resistance of metal components in highly corrosive chlorine-containing environments of seawater and the like.

Combined treatment method for improving corrosion resistance of metal component in chlorine-containing solution

A laser shock peening method for an additive manufactured component of a double-phase titanium alloy is provided. First, a three-dimensional digital model of a complex component is obtained, and the model is divided into a plurality of slices; a forming direction of a formed part in an additive manufacturing process is determined according to a stress direction of the additive manufactured component in an engineering application; then, the component of the double-phase titanium alloy is formed and manufactured by selective laser melting, and orientations of a C-axis of an &#x3b1; phase is allowed to be consistent through adjustment and control; and finally, laser shock peening is performed on all outer surfaces of the high-performance additive manufactured component of the double-phase titanium alloy by inducing a high-intensity shock wave to act in an acting direction which forms an angle in a predetermined range with the C-axis of the &#x3b1; phase.

Laser shock peening method for additive manufactured component of double-phase titanium alloy

A double-side synchronous laser shock peening (LSP) method for leading edges of turbine blades employs two laser beams with the same diameter and different pulse energy to synchronously shock the front and back sides of each point within 8-10 mm range of the leading edge of the blade, wherein the laser pulse energy on the front side is greater than the laser pulse energy on the back side, and wherein, the laser power density on the front side is used to generate dynamic plastic deformation on the entire laser-shock spot area, while the laser power density on the back side is used to balance off excessive shock-wave pressure in the central area of laser-shock spot on the front side and avoid macroscopic deformation of the blade in the central area of laser-shock spot on the front side, and an optimal strengthening effect is achieved finally.

Double-side synchronous laser shock peening method for leading edge of turbine blade

The invention relates to additive manufacturing field and laser shock peening (LSP) field, in particular to a combined apparatus for layer-by-layer interactive additive manufacturing with laser thermal/mechanical effects. In the apparatus, a LSP module and a SLM module operate in alternate so as to perform LSP for the formed part in the forming process of the formed part, and thereby a better strengthening effect of the formed part is achieved. The invention effectively overcomes the challenges of 'shape control' against deformation and cracking of the formed parts incurred by internal stress and 'property control' against poor fatigue property of the formed parts incurred by metallurgical defects during additive manufacturing, improves fatigue strength and mechanical properties of the faulted parts, and realizes high-efficiency and high-quality holistic processing of the formed parts.

Combined apparatus for layer-by-layer interactive additive manufacturing with laser thermal/mechanical effects

A method for laser shock peening (LSP) to uniformly strengthen metallic components uses varied square-spot LSP with stagger multiple-layer. Each layer is subjected to square-spot LSP treatment, without overlapping. The length of square-spot in the first layer is larger than those in the second layer and third layers, and the length of square-spot in the second layer is equal to that in the third layer. The first layer treated by LSP is used to reduce deeper localized compressive residual stress, and the second and third layers imparted by square-spot LSP with staggered distance are used to eliminate of the boundary effect and decrease surface roughness.

Kind of uniform strengthening methods of turbine blade subjected to varied square-spot laser shock peening with stagger multiple-layer

Provided is a laser shock peening method for obtaining a large-area uniform surface morphology. Using the relationship between the thickness of an absorption layer and a plastic deformation due to the laser shock peening and using a grid-shaped absorption layer () having a staggered distribution in thickness in cooperation with a two-layer interlaced laser shock processing method significantly reduce the height difference between micro-protrusions () and micro-pits () produced by an impact of a square light spot, and effectively reduce the roughness of the workpiece surface such that a large-area uniform surface morphology is formed on the workpiece surface.

Laser shock peening method for obtaining large-area uniform surface morphology

A method and device for strengthening the laser shock of a hidden surface includes establishing a continuous laser shock strengthening track and process after acquiring the information about the whole hidden surface. A control system adjusts the movement and rotation of a total reflection mirror which is arranged in a workpiece according to the signal from signal collecting cards for making a reflected laser beam act on a region to be machined of the hidden surface at an appropriate incidence angle. The method can realize the surface strengthening treatment of the hidden surface of the workpiece, significantly improve the mechanical performance of the workpiece and increase the fatigue life thereof, which is applicable to the surface strengthening of the workpiece with the hidden surface.

Method and device for strengthening laser shock of hidden surface

A remanufacturing method for a metal part having a damage. The damage groove is divided into a number of levels, and the groove bottom is treated by absorption layer-free laser shock peening to remove surface impurities and to refine surface-layer crystal grains. Then a cladding layer is formed by laser cladding. The process is repeated until the groove is completely filled by the cladding layer to higher than the surface of the metal part and the cladding layer higher than the surface is cut by a mechanical processing and polished, and the upper surface of the laser cladding layer is subjected to large-area overlapped laser shock peening.

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Jiangsu, China

Kaiyu Luo