40results about How to "Improve laser power density" patented technology

The invention discloses a device and method for impacting and strengthening a fastening hole through ring laser. The device is arranged above a laser impacting and strengthening object provided with a fastening hole and comprises an inner concave cone lens provide with a center hole, a focusing lens provide with a center hole, an outer convex cone lens and a focusing lens, which are sequentially and coaxially arranged from top to bottom; the lenses are arranged on an optical lens adjusting frame; the lenses are coaxially arranged with the fastening hole; a ring laser beam with diameter larger than the aperture of the center hole of the inner concave cone lens is axially incident from the upper side of the inner concave cone lens. The device disclosed by the invention can spatially separate the ring laser beam, couple the separated ring laser beams into a new ring laser beam and regulate the spatial energy distribution of the new ring laser beam to improve the bearable laser power density, and the ring laser beam is used for impacting, strengthening, regulating and controlling the residual stress distribution on the surrounding of the fastening hole end so as to further improve the fatigue performance of the fastening hole. The device disclosed by the invention is capable of increasing the utilization rate of laser pulse energy, simple to operate and convenient to promote and use.

The invention relates to a device and a method for massively preparing graphene from a carbon material in a laser shock liquid medium. The device comprises a system for preparing graphene through laser, and a system for transferring the graphene on different substrates. Laser generated by a high-power pulse laser generator is reflected by a light mirror, the obtained laser beam is vertically focused in a proper position of the upper surface of a graphite block target material in an aqueous solution medium, a direct current electric field with the voltage being direct current 24 V is applied totwo ends of the graphite target material, one electrode of the electric field is a copper plate fixed at one end of a reaction tank, the other end of the reaction tank adopts copper foil, a motor drives the copper foil to move at a constant speed, a high-temperature and high-voltage plasma is formed between the graphite and the aqueous medium at the moment of shocking the graphite with the laser,the plasma adheres to the surface of the copper foil under the driving of the electric field, the plasma is continuously adhered, and the copper foil continuously moves in order to finally achieve the purpose of continuous massive preparation of the graphene.

The invention provides a laser cutting system and a laser cutting method thereof. The laser cutting system comprises a galvanometer system, a variable reflector, a fixed reflector, a first laser, a second laser and a control system. The control system is connected with the first laser, the second laser and the variable reflector. The cutting mode is the front focusing cutting mode. According to a rear focusing cutting mode adopted by existing pole piece cutting, the focusing spot of front focusing is smaller than that of rear focusing, the laser power density at the focusing spot is larger, cutting speed can be increased, through matching with a three-axis galvanometer, the cutting range is large, large-breadth cutting and small-breadth batch cutting can be conducted, cutting efficiency is improved, and cost is reduced.

The invention provides an unmanned aerial vehicle laser relay redirection energy transmission device, and belongs to the technical field of laser assisted machining. The unmanned aerial vehicle laserrelay redirection energy transmission device comprises an unmanned aerial vehicle provided with a redirector and a laser device provided with a master control system and an emitter. Communication signals are established between the unmanned aerial vehicle and the master control system. The master control system is used for controlling the laser device to generate lasers with different power. The laser device is connected with the emitter capable of steering by optical fibers. The emitter is used for tracking and aiming the redirector capable of steering. The redirector is used for reflecting and focusing the laser onto a target. Through adjusting the steering of the emitter and the redirector, a systematic observation optical path being coaxial with a laser emission path is achieved. The unmanned aerial vehicle is not necessarily provided with the heavy laser device, through adjusting the redirector to aim at the target and adjusting the emitter to track and aim the redirector, bypassing an obstacle can be effectively achieved through reflection, and the laser can be transmitted and focused onto the target.

The invention belongs to the field of optical design and discloses a laser variable-taper variable-diameter rotary cut hole machining optical system. The system is provided with a rotary shaft and comprises the following optical components which are arranged in sequence along a light path and include a laser light beam one-way compression assembly, a first wedge-shaped lens set, a single-lens wedge-shaped lens (7), a focus lens (8) and a second wedge-shaped lens set, wherein the first wedge-shaped lens set is composed of two wedge-shaped lenses which are the same in wedge angle and is used foradjusting the offset of laser light beams; the single-lens wedge-shaped lens is used for inducing the laser inclination angle; and the second wedge-shaped lens set is composed of two wedge-shaped lenses which are the same in wedge angle and is used for adjusting the offset of focused light spot. By modifying composition of all the components and cooperative work modes among all the components, the laser inclination angle and the offset from the laser focal point to an optical axis can be independently adjusted in a large range, then the required hole diameter and taper proportioning can be achieved, focused light spot distortion caused by coma after laser focused light spot leaves the optical axis and inclines can be compensated, and the laser variable-taper variable-diameter rotary cut hole machining process which is good in machining effect is achieved.

The invention relates to TiAl-based abrasion-resistant laser cladding coating powder and a preparation method thereof, and belongs to the technical field of laser cladding metal material surface modification. The TiAl-based abrasion-resistant laser cladding coating powder is composed of the following components of, by mass, 60.5%-86.5% of TiAl intermediate alloy powder, 10%-20% of Si powder, 1%-10% of HfO2 powder, 1%-5% of La2O3 powder, 1%-3% of B powder and 0.5%-1.5% of CeO2 powder. A coating which has high hardness and high abrasion resistance and is metallurgically bonded with a substrate is prepared on the titanium alloy substrate.

The invention relates to the technical field of automobile brazing, in particular to a high-speed laser brazing method for an automobile ceiling. The method includes the following steps that a weldingwire and the automobile ceiling are both electrically connected with a heating power source, laser beams generated by a laser generating device are focused onto a welding line of the automobile ceiling, and laser spots are formed on the welding line; the welding wire is fed into the laser spots through a wire feeding device, and meanwhile the welding wire makes contact with the automobile ceiling; the welding wire is molten under the joint effects of laser energy and resistance heat, a molten pond is formed, and the position, making contact with the molten pond, of the welding wire is locatedon the front edge of the molten pond; and the laser spots generated by the laser generating device and the wire feeding device drive the welding wire to move and perform welding along the trajectorywhere the welding line is located. The high-speed laser brazing method for the automobile ceiling inhibits generating of hump weld passes and figures of fish scale in the brazing process, and achievesthat the brazing speed of the automobile ceiling reaches 100-120 mm / s.

The invention relates to a scanning laser-TIG electric arc composite penetration fusion welding method. The method comprises the steps that a laser beam and TIG electric arc both act on a workpiece, awelding pool is formed, the laser beam is vertically downwards arranged, and the TIG electric arc is arranged on the rear side of the laser beam and is oblique by a certain angle. During composite welding, the front end of the welding pool of the workpiece is filled with a welding wire, by adjusting the scanning track, the scanning frequency and the scanning range of the laser beam, the scanningpath of a focal spot of the laser beam is oval or round in the workpiece thickness direction, a weld joint is formed, and workpiece welding is completed. By means of the method, small hole stability is facilitated, the welding quality is easily improved, then the back bead width and weld joint back width ratio of the penetration fusion weld joint is improved, and the mechanical properties of a joint are further improved.

A cross flow CO2 laser uses a three-segment optical cavity apparatus, and is composed of a front and a rear optical cavity bodies with same structure, wherein the optical cavity body includes a reflection mirror and integration regulating mechanism, a non-coaxial double-accordion pipe mechanism, a window mirror seat and rear inverse mirror seat regulating mechanism, an optical cavity mechanical locating and cavity mirror regulating mechanism, a optical cavity exterior cold water circulation mechanism. The two accordion pipes are sealing mounted on two surfaces of a middle integrated flange, wherein the shaft lines have space length with each other, and the other two ends of the accordion pipes are connected to a regulation flange and an end flange separately; the end flange connecting with the window mirror seat and rear inverse mirror seat regulating mechanism, the regulation flange connecting with the optical cavity case body, the reflection mirror and an absorption cold light plate being mounted on the middle integrated flange; the laser has professional design, simple structure, convenient regulation, longer service lifetime, less elements, dependable performance and stronger practicability, scientificaalness and operability. The cavity type can be changed simply without regulating cavities, by means of adding simple interface accessory and improving the foundation structure of light bridge based on the structure.

The invention relates to an energy conversion module used for a laser power supply system. An optical fiber interface is installed on the bottom surface of a base. A cavity is formed in the base above the optical fiber interface. A protection sheet is embedded in the base below the cavity and close to the optical fiber interface. A heat dissipation sheet is embedded in the cavity above the protection sheet. The surface, facing the protection sheet, of the heat dissipation sheet is provided with a laser energy conversion chip. Two levels of the laser energy conversion chip are connected with two pole plates extending out of the base from the cavity opening above the heat dissipation sheet. According to the invention, the heat dissipation effect is good, the chip is enabled to receive lasers with higher power density, a high-precision ceramic sleeve is embedded in the optical fiber interface, the coupling precision between the laser energy conversion chip and lasers is improved, the consistency of product output performance is improved, the novel module good in heat dissipation performance, high in output performance, good in reliability, low in cost, simple in assembling process and stable in work is realized, and the energy conversion module can work stably in laser power supply systems of different fields for a long time.

The invention discloses a pointing control method for light beam synthesis on a self-adaptive optical fiber collimator array target, which comprises the following steps of: firstly, respectively coupling a path of indication light with different wavelengths in each main laser beam, detecting the position of each indication light beam on the target through a photoelectric detection system, and adjusting the pointing direction of each self-adaptive optical fiber collimator to obtain a light beam synthesis direction; and the position of the corresponding indication light on the target coinciding with the specified position, so that each main laser beam can act on the specified position on the target. According to the invention, the pointing control problem of light beam synthesis on a target of the self-adaptive optical fiber collimator is solved, the laser power density on the target is improved, and the action effect of the laser beam is improved.

The invention discloses a laser tempering quenching method. The technical problem that in the prior art, due to the fact that heat treatment is not in place or the density or hardness of a base body is different, the hardness of the quenched surface is still extremely uneven after heat treatment is solved. Comprising the steps of preparation before machining, primary scanning laser tempering, natural cooling, secondary scanning laser quenching, detection and the like, and the specific principle is that gas assistance and two times of non-constant-speed scanning are adopted to achieve the purpose of strengthening a part to be quenched; the two scanning speeds are inconsistent, the first scanning speed is high, the second scanning speed is low, the power is kept consistent and the gas flow is kept unchanged in the whole process, and gas is blown to the laser spot position of the surface to be quenched at a fixed angle at any moment in the quenching process, so that the purpose of uniform surface hardness of the quenched surface is achieved.

The invention relates to a method for applying laser drilling to sapphire slice drilling. The method comprises a first step of fixing a sapphire slice on an operating platform of a laser device and enabling a laser emission head of the laser device to be aligned to a position to be drilled on the sapphire slice, a second step of setting parameters of the laser device according to the thickness of the sapphire slice, and a third step of starting the laser device to enable the laser device to emit laser beams towards the position to be drilled on the sapphire slice, wherein the second step comprises a first step of setting parameters of the laser device according to the thickness of the sapphire slice and a formula (1), a second step of determining laser emission frequency of the parameters of the laser device according to determined energy in the parameters of the laser device and a formula (2), a third step of determining feed rate of the parameters of the laser device according to determined laser emission frequency of the parameters of the laser device and a formula (3), a fourth step of setting 0.3-0.5 ms as the wave width of the parameters of the laser device, and a fifth step of adjusting Hgt% of the parameters of the laser device to enable average power of the laser device to be 255 W.

The invention discloses a cascaded nonlinear optical frequency conversion device for realizing 1064nm to 400-450nm blue-violet light, and belongs to the field of laser technologies and nonlinear optical technologies. A 1064nm laser resonant cavity is formed by a resonant cavity input mirror and a resonant cavity output mirror; a resonant cavity intermediate mirror is placed in the 1064nm laser resonant cavity, and a 1064nm laser medium and a Q switch are sequentially placed between the resonant cavity input mirror and the resonant cavity intermediate mirror; nonlinear crystals with different functions are sequentially placed between the resonant cavity intermediate mirror and the resonant cavity output mirror; the 1064nm laser pumping OPO crystal generates 1.5[mu]m waveband laser, and generation of 400-450nm waveband blue-violet laser is further realized through combined design of frequency multiplication and sum frequency of the 1064nm waveband laser and the 1.5[mu]m waveband laser inthe cavity. According to the invention, an intracavity nonlinear optical frequency conversion mode is adopted, and the conversion efficiency of nonlinear optical frequency conversion is improved; andas an OPO crystal, a 1064nm pumping non-critical phase matching structure is realized, and the generation of 1.5[mu]m waveband laser with maximum efficiency is ensured.

The invention provides a low-quantum-loss sheet laser. The laser comprises a first resonant cavity which comprises a dichroic mirror, a first sheet gain module, and a second sheet gain module; and a second resonant cavity which comprises a 1030nm / 1048nm high-reflectivity mirror and a coupling output mirror. The second resonant cavity and the first resonant cavity share the first sheet gain module;the first resonant cavity generates 1030 nm laser, and pumps the first sheet gain module to enable the first sheet gain module to generate population inversion, so the second resonant cavity generates oscillation, and the 1048 nm laser beam is output from the coupling output mirror. The invention further provides a laser output method. The laser and the method are low in energy quantum loss, goodin light beam quality and high in output power.

The invention discloses a laser quenching device which comprises a working table and a laser assembly disposed above the working table, wherein the laser assembly comprises a laser, a beam expander, agalvanometer and an F-Theta lens arranged in sequence in a beam transmission direction. The multi-dimensional dynamic galvanometer ensures that light spots cannot be distorted within an effective range; the software control is accurate, the quenching depth can be precisely controlled, and the laser output energy, a scanning path and the like can be precisely controlled, so that an internal crystal structure is more refined, a hot deformation zone of a probe and the overall change are small, the product consistency and the yield rate are greatly improved, the hardness is increased by 15% to 20% compared with that of the conventional quenching, and the wear resistance can be increased by 3-4 times; no relatively long-term pretreatment and heating of the conventional method are required; theenergy consumption is reduced; laser-scanned probes do not need to be immersed in anti-rust oil, thereby reducing secondary pollution; and the laser quenching device is short in process cycle, high in production efficiency and low in cost, can be incorporated into a production line, and facilitates mass production.

The invention discloses a cylindrical lens focusing-based handheld welding optical mechanism and a working method thereof. The mechanism comprises a handheld welding optical mechanism body, a collimating mirror set, a planar mirror, a first cylindrical lens, a second cylindrical lens and a protective glass. The mechanism has the advantages that the structural design is novel, the one-piece cylindrical lens is moved in the optical axis direction based on the one-way focusing characteristic of the cylindrical lenses, the elliptic shaping of focused beam segment spots and the continuous adjustable length in one-way direction of the any-section spots are realized, the laser power density of the focusing spots is conveniently reduced, so that the power required by plate welding is reduced, thewelding speed is conveniently improved, the adaptability of the welding seam width is conveniently improved, and the mechanism is suitable for laser welding applications, and is particularly suitablefor handheld welding applications of different seam-width plates.

The invention relates to a laser power density adjusting method, a laser power density adjusting device and a storage medium. The method includes: controlling an optical fiber in a working area, and fixing the optical fiber at a preset position in the working area; acquiring a vertical distance between a tip end of the optical fiber from a plane to be applied; acquiring a value of a scattering angle of a laser beam emitted by the optical fiber when a laser spot of the laser beam emitted by the optical fiber completely covers a region to be applied in the plane to be applied; calculating the power value of the laser according to the vertical distance between the tip end of the optical fiber from the plane to be applied, the value of the scattering angle of the laser beam and a preset targetlaser power density value; and adjusting the power of the laser to a power value to obtain the laser power density corresponding to the preset target laser power density value. The method can obtainaccurate laser power density without manual attempts and adjustments, and can improve efficiency and accuracy of laser power density acquisition.

The invention relates to a method for applying laser drilling to sapphire slice drilling. The method comprises a first step of fixing a sapphire slice on an operating platform of a laser device and enabling a laser emission head of the laser device to be aligned to a position to be drilled on the sapphire slice, a second step of setting parameters of the laser device according to the thickness of the sapphire slice, and a third step of starting the laser device to enable the laser device to emit laser beams towards the position to be drilled on the sapphire slice, wherein the second step comprises a first step of setting parameters of the laser device according to the thickness of the sapphire slice and a formula (1), a second step of determining laser emission frequency of the parameters of the laser device according to determined energy in the parameters of the laser device and a formula (2), a third step of determining feed rate of the parameters of the laser device according to determined laser emission frequency of the parameters of the laser device and a formula (3), a fourth step of setting 0.3-0.5 ms as the wave width of the parameters of the laser device, and a fifth step of adjusting Hgt% of the parameters of the laser device to enable average power of the laser device to be 255 W.

The invention discloses a beam expanding and real-time focusing device based on a CO2 laser tube light source. Two 45-degree plane mirrors are utilized to turn an optical axis direction of a CO2 laserbeam by 180 degrees, thereby shortening a laser emission cylinder, realizing miniaturization and portability of the laser emission cylinder, and facilitating field transportation and work; and real-time focusing can be performed according to the distance of a target, thereby achieving the effects that for targets of different distances, under the condition of constant laser tube power, CO2 laserspots are the smallest, laser power density is the highest, and a capability of clearing foreign matter is the highest.

The invention relates to a device and a method for massively preparing graphene from a carbon material in a laser shock liquid medium. The device comprises a system for preparing graphene through laser, and a system for transferring the graphene on different substrates. Laser generated by a high-power pulse laser generator is reflected by a light mirror, the obtained laser beam is vertically focused in a proper position of the upper surface of a graphite block target material in an aqueous solution medium, a direct current electric field with the voltage being direct current 24 V is applied totwo ends of the graphite target material, one electrode of the electric field is a copper plate fixed at one end of a reaction tank, the other end of the reaction tank adopts copper foil, a motor drives the copper foil to move at a constant speed, a high-temperature and high-voltage plasma is formed between the graphite and the aqueous medium at the moment of shocking the graphite with the laser,the plasma adheres to the surface of the copper foil under the driving of the electric field, the plasma is continuously adhered, and the copper foil continuously moves in order to finally achieve the purpose of continuous massive preparation of the graphene.

The invention provides a laser cutting system and a laser cutting method thereof. The laser cutting system comprises a galvanometer system, a variable reflector, a fixed reflector, a first laser, a second laser and a control system. The control system is connected with the first laser, the second laser and the variable reflector. The cutting mode is the front focusing cutting mode. According to a rear focusing cutting mode adopted by existing pole piece cutting, the focusing spot of front focusing is smaller than that of rear focusing, the laser power density at the focusing spot is larger, cutting speed can be increased, through matching with a three-axis galvanometer, the cutting range is large, large-breadth cutting and small-breadth batch cutting can be conducted, cutting efficiency is improved, and cost is reduced.

The invention discloses a folding optical fiber laser emitting device which comprises a QBH optical fiber head, a folding reflection box and a sighting telescope installed at the top of the box body.The QBH optical fiber head is used for emitting laser, a light inlet and a light outlet which are vertically parallel are formed in one face of the light path reflection box, and the QBH optical fiberhead is installed on the light inlet. The incident surface of a first reflector faces the laser emitting end of the QBH optical fiber head, the reflecting surface of the first reflector faces the incident surface of a second reflector, the reflecting surface of the second reflector faces the light outlet, and a focusing lens is located between the second reflector and the light outlet. A foldingstructure is adopted to increase the focal length of the lens and effectively compress the divergence angle of an emergent Gaussian beam, so that the target laser power density is improved; and meanwhile, the length of the folding reflection box is reduced due to the design of the folding light path, and carrying and using are convenient. The problem that the QBH optical fiber head affects aimingof an operator is solved, and the operator can approach the eyepiece of the optical sighting telescope with eyes for aiming without hindrance.

The invention discloses a laser light source module and a projection display system. The laser light source module comprises a semiconductor laser array packaged on a heat dissipation substrate; a stepped mirror array for reflecting the laser beam emitted by the semiconductor laser array; and an output surface arranged in the output direction of the reflected light. The semiconductor lasers in thesemiconductor laser array are staggered at preset intervals. The stepped mirrors in the stepped mirror array are corresponding to the semiconductor lasers and are staggered along the laser emitting direction of the semiconductor laser array so that the laser beam emitted by the semiconductor lasers is reflected by the corresponding stepped mirrors once and then outputs light spots to the output surface. The laser light source module only needs to perform one time of reflection so that the row spacing and the column spacing between the light beams can be reduced, the smaller volume can be ensured, the higher laser power density can be obtained and the energy loss caused by secondary mirror reflection and the technological complexity can be avoided.

The invention discloses a method for improving 850nm semiconductor laser power density. According to the method, a 850nm semiconductor laser single-tube module (1), collimating mirrors (2), optical fibers (3), an annular fixator (4), a hollow trapezoidal circular truncated cone (5) and a focusing mirror (6) are adopted. The hollow trapezoid circular truncated cone (5) comprises a circular truncated cone upper bottom face (5-1), a circular truncated cone outer side face (5-2), a circular truncated cone lower bottom face (5-3) and a circular truncated cone inner side face (5-4); the light of the 850nm semiconductor laser single-tube modules (1) is coupled into the optical fibers (3) through the collimating mirrors (2); the optical fibers (3) pass through the annular fixator (4) and then the light vertically enters the lower bottom face (5-3) of the hollow trapezoidal circular truncated cone (5), undergoes total reflection at the outer side face (5-2) and the inner side face (5-4) of the circular truncated cone and enters the focusing mirror (6); and therefore, 850nm semiconductor laser output can be improved.

The invention relates to a combined laser plasma anticonductance system and method. The system comprises at least one femtosecond laser used for starting plasmas, a nanosecond laser used for stabilizing the plasmas, a reflecting mirror used for reflecting the femtosecond laser and a coupling mirror used for laser coupling. The method comprises the following steps: step 1, starting the femtosecondlaser to generate femtosecond laser according to femtosecond starting parameters so as to form a plasma channel in the air; step 2, repeatedly refreshing the plasma channel by using the femtosecond laser according to a preset femtosecond repetition frequency; step 3, starting the nanosecond laser to generate nanosecond laser according to the nanosecond starting parameters, wherein the nanosecond laser is coupled with the femtosecond laser through the coupling mirror and then acts on the plasma channel; and step 4, repeatedly refreshing the plasma channel by using the nanosecond laser accordingto the preset nanosecond repetition frequency. According to the system and the method, the stability of the plasma channel can be improved, and the service life of the plasma channel can be prolongedso that a continuous plasma region with a relatively large region is formed.

The invention discloses a 1.17-micron self-Raman laser intracavity pumping 3-micron holmium-doped solid laser which comprises a 0.8-micron semiconductor laser pumping source, an input mirror, a neodymium-doped laser self-Raman medium, an intermediate mirror, a holmium-doped solid laser medium and an output mirror. By carrying out reasonable film coating on the input mirror, the intermediate mirror and the output mirror, the input mirror and the output mirror form a resonant cavity of 1-micron fundamental frequency light and 1.17-micron Raman laser; the intermediate mirror and the output mirror form a 3-micron laser resonant cavity; the neodymium-doped laser self-Raman medium is used for absorbing 0.8-micron laser to generate 1-micron fundamental frequency light and 1.17-micron Raman laser, and is oscillated in the resonant cavity of the 1-micron fundamental frequency light and the 1.17-micron Raman laser; the holmium-doped solid laser medium is used for absorbing 1.17-micron Raman laser to generate 3-micron laser, one part of the laser oscillates in the 3-micron laser resonant cavity, and the other part of the laser directly outputs the 3-micron laser from the output mirror. According to the invention, the existing semiconductor laser can be utilized, the cost performance is high, and the continuous and stable output of 3-micron laser can be realized.

The invention relates to an energy conversion module used for a laser power supply system. An optical fiber interface is installed on the bottom surface of a base. A cavity is formed in the base above the optical fiber interface. A protection sheet is embedded in the base below the cavity and close to the optical fiber interface. A heat dissipation sheet is embedded in the cavity above the protection sheet. The surface, facing the protection sheet, of the heat dissipation sheet is provided with a laser energy conversion chip. Two levels of the laser energy conversion chip are connected with two pole plates extending out of the base from the cavity opening above the heat dissipation sheet. According to the invention, the heat dissipation effect is good, the chip is enabled to receive lasers with higher power density, a high-precision ceramic sleeve is embedded in the optical fiber interface, the coupling precision between the laser energy conversion chip and lasers is improved, the consistency of product output performance is improved, the novel module good in heat dissipation performance, high in output performance, good in reliability, low in cost, simple in assembling process and stable in work is realized, and the energy conversion module can work stably in laser power supply systems of different fields for a long time.

The invention relates to a scanning laser-TIG electric arc composite penetration fusion welding method. The method comprises the steps that a laser beam and TIG electric arc both act on a workpiece, awelding pool is formed, the laser beam is vertically downwards arranged, and the TIG electric arc is arranged on the rear side of the laser beam and is oblique by a certain angle. During composite welding, the front end of the welding pool of the workpiece is filled with a welding wire, by adjusting the scanning track, the scanning frequency and the scanning range of the laser beam, the scanningpath of a focal spot of the laser beam is oval or round in the workpiece thickness direction, a weld joint is formed, and workpiece welding is completed. By means of the method, small hole stability is facilitated, the welding quality is easily improved, then the back bead width and weld joint back width ratio of the penetration fusion weld joint is improved, and the mechanical properties of a joint are further improved.