Competitive phase dynamics design-based laser in-situ welding method for inhibiting SiCp / Al interface reaction

Abstract

The invention discloses a competitive phase dynamics design-based laser in-situ welding method for inhibiting SiCp / Al interface reaction. The competitive phase dynamics design-based laser in-situ welding method comprises the following steps of: fixing a middle layer and SiCp / Al composite materials positioned on two sides of the middle layer; and the SiCp / Al composite material and the middle layer are formally welded through a continuous laser beam. According to the chemical metallurgical performance of the SiCp / Al composite material, design and in-situ laser welding are carried out through the competitive phase kinetic principle between an Al4C3 brittle phase generated through the interface reaction of the material and an intermetallic compound generated through the laser in-situ reaction of a connector, the interface reaction during fusion welding of the SiCp / Al composite material is inhibited, generation of the hard and brittle Al4C3 phase is avoided, and the fusion welding quality of the SiCp / Al composite material is improved. And a high-quality welding joint is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of material processing engineering, and in particular relates to a laser in-situ welding method based on competitive phase kinetic design for inhibiting SiCp / Al interface reaction. Background Art

[0002] Lightweight, integrated, and large-scale are the development trends of the new generation of aerospace equipment. Silicon carbide particle reinforced aluminum-based composite materials (SiCp / A1) have significant advantages in structural weight reduction, rigidity improvement, and dimensional stability. However, with the promotion and application of SiCp / A1 composite materials in major national fields, its welding technology faces many challenges and has become a bottleneck restricting its development. The main reason is that during fusion welding, the SiC reinforcement phase particles in the joint are prone to interface reaction with the Al matrix to generate Al4C3 brittle intermetallic compounds, which seriously reduce the performance of the joint.

[0003] At present, there are three main methods to inhibit the interface reaction of aluminum-based composite materials, namely, adjusting parameters such as laser power during welding, using low-carbon filler materials to react with the aluminum matrix, and physical and chemical treatment methods. During welding, parameters such as laser power are adjusted to control heat input and reduce overheating at the interface, thereby inhibiting the formation of Al4C3. However, the process window is relatively narrow, the adaptability is poor, and it is difficult to maintain stable welding quality under different welding conditions; using low-carbon filler materials to react with the aluminum matrix to generate stable compounds can effectively prevent the interface reaction, but this method often requires higher welding temperatures or complex processes, and the filling amount is difficult to better regulate the joint performance, and the weld stability is poor; while the physical and chemical treatment method requires additional process steps, which increases the complexity of the process. Therefore, there is an urgent need for a new and effective welding method that can simplify the process and reduce production costs while maintaining welding quality. Summary of the invention

[0004] In view of the problems that the methods for inhibiting the interface reaction of aluminum-based composite materials in the prior art are complicated and have high production costs, the purpose of the present invention is to provide a laser in-situ welding method based on competitive phase kinetics design for inhibiting SiCp / Al interface reaction. The method accurately controls laser parameters and welding environment during the welding process, combines thermodynamics and kinetics analysis, and inhibits the occurrence of interface reaction according to the competitive kinetics of substitution phases, thereby improving the quality and reliability of the welded joint, effectively solving the current technical difficulties in the welding of SiCp / Al composite materials, and obtaining a laser in-situ welded joint with good forming and excellent joint performance.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A laser in-situ welding method based on competitive phase kinetic design for inhibiting SiCp / Al interface reaction comprises the following steps: Fixing the middle layer to the SiCp / Al composite material located on both sides of the middle layer; The SiCp / Al composite material and the intermediate layer are formally welded by continuous laser beam.

[0006] Furthermore, the volume fraction of SiC particles in the SiCp / Al composite material is 5-20%.

[0007] Furthermore, when the SiCp / Al composite material and the intermediate layer are formally welded by continuous laser beam, the laser center is located at the center of the butt joint.

[0008] Furthermore, when the SiCp / Al composite material and the intermediate layer are formally welded by a continuous laser beam, the laser beam is tilted by 5 to 15 degrees.

[0009] Furthermore, the process parameters of continuous laser beam formal welding are: Laser power: 1000 W ~4000 W; Welding speed: 1.0 m / min ~ 8.0 m / min; Defocus: -5 mm ~ 5 mm; Protective gas: Ar; Shielding gas flow rate: 15 L / min ~ 25 L / min.

[0010] Furthermore, the welding start point and the end point are positioned as the butt joint center.

[0011] Furthermore, it also includes: before the SiCp / Al composite material and the intermediate layer are formally welded by continuous laser beam, the laser light stays for 0.1 to 0.5 seconds after being emitted to form a laser pinhole.

[0012] Furthermore, before the SiCp / Al composite material and the intermediate layer are formally welded by continuous laser beam, the gas is pre-filled for 10 to 20 seconds, and welding begins after the welding cavity is filled with protective gas.

[0013] Furthermore, after the continuous laser beam formally welds the SiCp / Al composite material and the intermediate layer, the laser stays at the end point and the gas is maintained for 5 to 15 seconds until it cools below the phase change temperature of the material before stopping the gas protection.

[0014] Furthermore, the SiCp / Al composite material and the intermediate layer are made of two different materials.

[0015] Compared with the prior art, the present invention has the following beneficial effects: According to the chemical metallurgical properties of SiCp / Al composite materials, the present invention designs and performs in-situ laser welding based on the competitive phase dynamics principle between the Al4C3 brittle phase generated by the interface reaction of the material itself and the intermetallic compound generated by the laser in-situ reaction of the joint, thereby suppressing the interface reaction during the fusion welding of the SiCp / Al composite materials, avoiding the generation of the hard and brittle Al4C3 phase, and obtaining a high-quality welded joint. The present invention adopts a laser in-situ welding method to systematically analyze the replacement phase generated during the welding process, promote the formation of a favorable phase structure, and enhance the strength and toughness of the welded joint. The present invention is not only applicable to SiCp / Al composite materials, but can also be extended to other types of metal-based composite materials, including but not limited to SiCw / Al-based composite materials, B4Cp / Al-based composite materials, and other aluminum-based composite materials containing C element reinforcement phases, such as graphite (Gr) / Al-based composite materials, carbon fiber (Cf) / Al-based composite materials, carbon nanotubes (CNTs) / Al-based composite materials, etc. These materials are widely used in aerospace, automotive industry, electronic devices and other fields. The laser in-situ welding method of the present invention can effectively improve the welding quality and joint performance of these composite materials, expand their application scope, and has important technical significance and economic value.

[0016] Furthermore, the present invention adopts a laser in-situ welding method based on competitive phase kinetics design to suppress SiCp / Al interface reaction, accurately controls laser parameters, and makes the welding process simpler, without the need for complex filling material application process or additional surface treatment steps, thereby reducing process complexity and production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, objects and advantages of the present invention will become more apparent from a reading of the detailed description of non-limiting embodiments made with reference to the following drawings; Figure 1 The morphology of the joints obtained by in-situ welding with TA1 and TC4 intermediate layers in Example 1 and Example 2 is compared with the morphology of the joints obtained by direct butt welding in Comparative Example 1, wherein (a) is the morphology of the joints obtained by direct laser welding without adding intermediate materials, (b) is the morphology of the joints obtained by applying the TA1 intermediate layer, and (c) is the morphology of the joints obtained by applying the TC4 intermediate layer; Figure 2 The strength of the joints obtained by the laser in-situ welding method for suppressing the interface reaction of SiCp / Al composite materials in Examples 1 and 2 of the present invention is compared with the tensile properties of the joints obtained by direct butt welding in Comparative Example 1. DETAILED DESCRIPTION

[0018] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several improvements and changes can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0019] The present invention proposes a laser in-situ welding method based on competitive phase kinetic design for inhibiting SiCp / Al interface reaction, comprising the following steps: Welding preparation steps: Select SiCp / Al composite materials reinforced with silicon carbide particles of a certain size and volume ratio, and determine the specifications of the materials to be welded. According to the alternative phase competition kinetics of the in-situ reaction, select strong carbide-forming elements or their prepared alloy materials that react before Al4C3 as the intermediate layer, such as Ti, Zr, V and other metals or alloys. The intermediate layer type can be wire, powder or foil, etc., and pre-treat the SiCp / Al composite materials and intermediate layer materials on both sides.

[0020] The pretreatment includes: any one or more combinations of mechanical grinding of the area to be welded, cleaning, alkali cleaning, pickling and drying; wherein, mechanical grinding: using an angle grinder to grind the front and back surfaces and the butt surfaces of the aluminum-based composite material to be welded to remove surface oil stains and impurities such as oxide films; alkali cleaning: preparing a sodium hydroxide aqueous solution with a mass concentration of 5%, soaking it in it for 10 minutes, stirring the solution during the period to facilitate uniform reaction and remove surface oil stains; pickling: preparing a dilute nitric acid aqueous solution with a mass concentration of 20%, placing the aluminum-based composite material in it and soaking it for 5 minutes, removing residual oxides and alkaline substances after alkali cleaning, and neutralizing; rinsing with alcohol and blowing dry, and wiping the surface of the aluminum-based composite material with absorbent cotton.

[0021] Fixing step: mechanically assemble the aluminum-based composite materials on both sides and the middle layer and fix them tightly; Among them, preferably, the aluminum-based composite material is a SiC particle volume fraction of 5-20%, and the intermediate layer is an Al4C3 alternative component considering the kinetics and thermodynamics of the in-situ reaction Gibbs free energy. Based on the competitive phase substitution kinetics, it can be designed through phase stability analysis, selection and design of kinetic paths, element interaction strength, etc., requiring the presence of the intermediate layer element to preferentially combine with the C element in SiC, and the product has a certain strength to optimize the joint performance.

[0022] Preferably, the thickness of the intermediate layer matches the thickness of the aluminum-based composite material in a certain ratio so as to avoid excessive fusion or insufficient reaction.

[0023] Welding steps: Formal welding of the aluminum matrix composite material and the intermediate layer by continuous laser beam; In the fixing step and the welding step, the aluminum-based composite materials on both sides and the parts to be welded of the middle layer are in a clean and weldable state, and formal welding is performed using a continuous laser beam, with the laser center located at the center of the butt joint.

[0024] Preferably, the mechanical assembly in the fixing step is performed using a clamp to ensure that the middle layer is tightly combined with the aluminum-based composite materials on both sides without leaving any gap.

[0025] Preferably, in the fixing step and the welding step, after the aluminum-based composite material-intermediate layer-aluminum-based composite material are assembled in sequence, the three layers of material are in a weldable state, and the formal welding is performed by continuous laser beam welding, and the center of the light spot is located at the center of the joint.

[0026] When mechanically assembled and fixed, the aluminum-based composite material, the middle layer, and the aluminum-based composite material are closely and evenly matched, without any bending of the middle layer or gap. When the laser beam is officially welding, the laser beam is tilted 5~15° to protect the laser protection lens from damage; Preferably, in the welding step, the process parameters of the laser formal welding are: Laser power: 1000 W ~4000 W; Welding speed: 1.0 m / min ~ 8.0 m / min; Defocus: -5 mm ~ 5 mm; Protective gas: 99.99% Ar; Shielding gas flow rate: 15 L / min ~ 25 L / min; Preferably, the welding start and end points are positioned as the docking center to ensure that the laser travel track is unbiased; Preferably, the laser in-situ welding method for suppressing the interface reaction of SiCp / Al composite materials provided by the present invention also includes: maintaining the stability of the molten pool: before starting welding, the laser stays for 0.1~0.5s after emitting light, and then proceeds to formally weld the SiCp / Al composite material and the intermediate layer through a continuous laser beam after forming a laser hole; a protection step: pre-inflate for 10~20s before the welding step begins, and welding begins after the welding cavity is filled with protective gas; after the welding is completed, the laser stays at the end point, the gas is maintained for 5~15s, and the gas protection is stopped after cooling to below the phase change temperature of the material.

[0027] Preferably, the aluminum-based composite material and the intermediate layer are made of two different materials.

[0028] Example 1 According to the laser in-situ welding method for inhibiting the interface reaction of SiCp / Al composite material provided by the present invention, 2mm15%SiCp / 2A14 Al (15% is the volume ratio of silicon carbide particles) is used as the base material to be welded, that is, SiCp / Al composite material, and according to the kinetic principle that Ti reacts preferentially with Al and C elements, TA1 foil is used as the intermediate layer material with a thickness of 0.01-0.10mm, comprising the following steps: Welding preparation steps: According to the phase diagram of SiCp / Al composite materials and the free energy changes of different carbides at different temperatures, the thermodynamic and kinetic reaction order is determined, and the appropriate material Ti foil is selected as the in-situ reaction intermediate layer to inhibit the interface reaction of SiCp / Al composite materials laser welding according to the competitive phase substitution kinetics. Both materials are pretreated; Fixing step: mechanically assembling the SiCp / Al composite material and the intermediate layer material; Welding steps: The 15% SiCp / 2A14 Al layered metal material with TA1 foil applied was formally welded by continuous laser beam; Wherein, the pretreatment includes: mechanical grinding of the area to be welded, cleaning, alkali cleaning, pickling and drying; In the fixing step and the welding step, the 15% SiCp / 2A14 Al substrate and the TA1 intermediate layer to be welded are both in a clean and weldable state, and formal welding is performed using a continuous laser beam, with the laser center located at the center of the butt joint.

[0029] Preferably, the mechanical assembly in the fixing step is performed using a special fixture to ensure that the middle layer is tightly combined with the SiCp / Al composite materials on both sides without leaving any gaps; the assembled material is a mechanically clamped 15%SiCp / 2A14 Al-TA1-15%SiCp / 2A14 Al material, all of which are in a weldable state, and the formal welding material is continuous beam laser welded, with the center of the light spot located at the center of the joint without deviating to any side.

[0030] Specifically: The continuous laser beam formal welding laser beam is tilted 10° in the direction after welding; Protection step: pre-fill for 15 seconds before welding, and start welding after the welding cavity is filled with protective gas; after welding, the laser stays at the end point, the gas is maintained for 10 seconds, and the gas protection is stopped after cooling to below the phase change temperature of the material.

[0031] In the welding steps, the process parameters of laser formal welding are: Laser power: 2000W; Welding speed: 1.5m / min; Defocus: 0mm; Protective gas: 99.99% Ar; Protective gas flow rate: 20L / min; The welding start and end points are positioned at the center of the butt joint, and the laser does not deviate to any side.

[0032] In the preferred example mentioned in the present invention, in terms of assembly method, after 15%SiCp / 2A14 Al-TA1-15%SiCp / 2A14Al is assembled, its center plane is in a vertical state and is tightly assembled without bending or uneven gaps; in terms of formal welding method, continuous laser beam welding is used, and the laser spot is located at the center of the 15%SiCp / 2A14 Al-TA1-15%SiCp / 2A14 Al joint.

[0033] More specifically, the laser in-situ welding method for suppressing the interface reaction of SiCp / Al composite materials provided in this embodiment also includes: maintaining the stability of the molten pool: before starting welding, the laser light stays for 0.3s after it is emitted, and then moves forward after a laser hole is formed; the intermediate layer of the laser in-situ welding for suppressing the interface reaction of SiCp / Al composite materials adopts TA1 titanium foil.

[0034] The continuous laser beam in-situ laser welding method of 15%SiCp / 2A14 Al-TA1-15%SiCp / 2A14 Al in the preferred example of the present invention proposes a new assembly, welding and protection scheme to address the problems that current welding is prone to defects and metallurgical reactions deteriorate joint performance. By adopting a tight butt assembly method, a large number of operating procedures and wire feeding parameter adjustment steps are omitted, and continuous welding after one clamping is achieved, which greatly simplifies the production process. It not only greatly improves the welding efficiency, but also facilitates the automation of the welding process.

[0035] Example 2 The continuous laser beam coupled intermediate layer TC4 laser welding method of the 15% SiCp / 2A14 Al composite material of the preferred embodiment of the present invention comprises the following steps: After the substrate 15%SiCp / 2A14 Al and the intermediate layer titanium alloy TC4 were selected, the substrate thickness was determined to be 2mm, the thickness of the titanium alloy TC4 was 0.05mm, and the width was 2mm; the substrate 2mm 15%SiCp / 2A14 Al and the intermediate layer titanium alloy TC4 were prepared by mechanical processing; the substrate 15%SiCp / 2A14 Al was mechanically polished, oil-cleaned, alkali-washed, pickled and dried; the materials to be welded were assembled and fixed by fixtures in the order of 15%SiCp / 2A14 Al-TC4 -15%SiCp / 2A14 Al; the connection of 15%SiCp / 2A14 Al-TC4-15%SiCp / 2A14 Al was achieved by continuous laser beam in-situ laser welding process, and the process parameters of the continuous laser beam were: laser power 3000W, welding speed 4.5m / min, defocusing amount 0 mm, shielding gas 99.99%Ar, and shielding gas flow rate 20L / min. After welding, the laser head is kept at the end position and the shielding gas flow is continuously output for 20 seconds until the weld joint cools to a lower temperature. Figure 1 (b)~(c) and Figure 2 As shown in the red and blue curves, TA1 or TC4 as an intermediate layer can better isolate the interfacial reaction that occurs in direct contact with the matrix, and the Ti element preferentially combines with the C element to form dispersed compounds such as TiC and TiAl3, avoiding the generation of brittle Al4C3 phase. No defects such as cracks and pores appear in the joint, and the joint quality is greatly improved.

[0036] Example 3 According to the laser in-situ welding method for inhibiting the interface reaction of SiCp / Al composite material provided by the present invention, 2mm5%SiCp / 2A14 Al (5% is the volume ratio of silicon carbide particles) is used as the base material to be welded, that is, SiCp / Al composite material, and according to the kinetic principle that Ti reacts preferentially with Al and C elements, TA1 foil is used as the intermediate layer material with a thickness of 0.01-0.10mm, comprising the following steps: Welding preparation steps: According to the phase diagram of SiCp / Al composite materials and the free energy changes of different carbides at different temperatures, the thermodynamic and kinetic reaction order is determined, and the appropriate material Ti foil is selected as the in-situ reaction intermediate layer to inhibit the interface reaction of SiCp / Al composite materials laser welding according to the competitive phase substitution kinetics. Both materials are pretreated; Fixing step: mechanically assembling the SiCp / Al composite material and the intermediate layer material; Welding steps: 5%SiCp / 2A14Al layered metal material with TA1 foil applied was welded by continuous laser beam; Wherein, the pretreatment includes: mechanical grinding of the area to be welded, cleaning, alkali cleaning, pickling and drying; In the fixing step and the welding step, the 5% SiCp / 2A14 Al substrate and the TA1 intermediate layer to be welded are both in a clean and weldable state, and formal welding is performed using a continuous laser beam, with the laser center located at the center of the butt joint.

[0037] Preferably, the mechanical assembly in the fixing step is performed using a special fixture to ensure that the middle layer is tightly combined with the SiCp / Al composite materials on both sides without leaving any gaps; the assembled material is a mechanically clamped 5%SiCp / 2A14 Al-TA1-5%SiCp / 2A14 Al material, all of which are in a weldable state, and the formal welding material is continuous beam laser welded, with the center of the light spot located at the center of the joint without deviating to any side.

[0038] Specifically: The continuous laser beam formal welding laser beam is tilted 5° in the direction after welding; Protection step: pre-fill for 15 seconds before welding, and start welding after the welding cavity is filled with protective gas; after welding, the laser stays at the end point, the gas is maintained for 10 seconds, and the gas protection is stopped after cooling to below the phase change temperature of the material.

[0039] In the welding steps, the process parameters of laser formal welding are: Laser power: 1000W; Welding speed: 1m / min; Defocus: -5mm; Protective gas: 99.99% Ar; Protective gas flow rate: 15L / min; The welding start and end points are positioned at the center of the butt joint, and the laser does not deviate to any side.

[0040] More specifically, the laser in-situ welding method for suppressing the interface reaction of SiCp / Al composite materials provided in this embodiment also includes: maintaining the stability of the molten pool: before starting welding, the laser light stays for 0.1s after it is emitted, and then moves forward after a laser hole is formed; the intermediate layer of the laser in-situ welding for suppressing the interface reaction of SiCp / Al composite materials adopts TA1 titanium foil.

[0041] Example 4 The continuous laser beam coupled intermediate layer TC4 laser welding method of the 20% SiCp / 2A14 Al composite material of the preferred embodiment of the present invention comprises the following steps: (1) After the substrate 20% SiCp / 2A14 Al and the intermediate layer titanium alloy TC4 are selected, the substrate thickness is determined to be 2 mm, the thickness of the titanium alloy TC4 is determined to be 0.05 mm, and the width is determined to be 2 mm; (2) The substrate 2 mm 20% SiCp / 2A14 Al and the intermediate layer titanium alloy TC4 were prepared by mechanical processing; (3) Mechanically polishing, cleaning of oil stains, alkali washing, pickling and drying of the substrate 20% SiCp / 2A14 Al; (4) Assemble and fix the materials to be welded in the order of 20%SiCp / 2A14 Al-TC4 -20%SiCp / 2A14 Al; (5) The continuous laser beam in-situ laser welding process was used to achieve the connection of 20%SiCp / 2A14 Al-TC4-20%SiCp / 2A14Al. The process parameters of the continuous laser beam were: laser power 4000 W, welding speed 8 m / min, defocusing amount 5 mm, shielding gas 99.99% Ar, and shielding gas flow rate 25 L / min.

[0042] (6) After welding, keep the laser head at the end position and continue to output the protective gas flow for 20 seconds until the weld joint cools to a lower temperature.

[0043] Comparative Example 1 The laser welding method of 15% SiCp / 2A14 Al composite material material by continuous laser beam without intermediate layer in comparative example 1 of the present invention comprises the following steps: The microstructure and properties of the 15% SiCp / 2A14 Al butt joint prepared in Comparative Example 1 are as follows: Figure 1 (a) and Figure 2 As shown in the black curve, direct butt welding without an intermediate layer will produce a large number of needle-shaped Al4C3 hard and brittle phases, which are cross-distributed. The wettability between the Al matrix, unreacted SiC particles and Al4C3 formed at the intersection is extremely poor, forming peeling tetrahedral pits ( Figure 1 In (a), these internal defects make the joint easy to crack when subjected to external force, and the joint quality is poor, only 224MPa, which is 54% of the tensile strength of the parent material. It can be seen that the intermediate layer in the present invention is needed.

[0044] The above description is only for the best embodiment of the present invention, but it should not be understood as limiting the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to be changed. However, all changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

Claims

1. A laser in-situ welding method based on competitive phase kinetic design for inhibiting SiCp / Al interface reaction, characterized in that: The following steps are involved: Fixing the middle layer to the SiCp / Al composite material located on both sides of the middle layer; The SiCp / Al composite material and the intermediate layer are formally welded by continuous laser beam.

2. The laser in-situ welding method based on competitive phase kinetic design for suppressing SiCp / Al interface reaction according to claim 1, characterized in that: The volume fraction of SiC particles in the SiCp / Al composite material is 5-20%.

3. The laser in-situ welding method based on competitive phase kinetic design for suppressing SiCp / Al interface reaction according to claim 1, characterized in that: When the SiCp / Al composite material and the intermediate layer are formally welded by continuous laser beam, the laser center is located at the center of the butt joint.

4. The laser in-situ welding method based on competitive phase kinetic design for suppressing SiCp / Al interface reaction according to claim 1, characterized in that: When the SiCp / Al composite material and the intermediate layer are formally welded by a continuous laser beam, the laser beam is tilted 5~15°.

5. The laser in-situ welding method based on competitive phase kinetic design for suppressing SiCp / Al interface reaction according to claim 1, characterized in that: The process parameters for continuous laser beam welding are: Laser power: 1000 W ~4000 W; Welding speed: 1.0 m / min ~ 8.0 m / min; Defocus: -5 mm ~ 5 mm; Protective gas: Ar; Shielding gas flow rate: 15 L / min ~ 25 L / min.

6. The laser in-situ welding method based on competitive phase kinetic design for suppressing SiCp / Al interface reaction according to claim 1, characterized in that: The welding start and end points are located at the butt center.

7. The laser in-situ welding method based on competitive phase kinetic design for suppressing SiCp / Al interface reaction according to claim 1, characterized in that: Also includes: Before the SiCp / Al composite material and the intermediate layer are formally welded by continuous laser beam, the laser stays for 0.1~0.5s after emitting light to form a laser pinhole.

8. The laser in-situ welding method based on competitive phase kinetic design for suppressing SiCp / Al interface reaction according to claim 1, characterized in that: Before the SiCp / Al composite material and the intermediate layer are formally welded by continuous laser beam, they are pre-filled for 10 to 20 seconds, and welding begins after the welding cavity is filled with protective gas.

9. The laser in-situ welding method based on competitive phase kinetic design for suppressing SiCp / Al interface reaction according to claim 1, characterized in that: After the continuous laser beam officially welds the SiCp / Al composite material and the middle layer, the laser stays at the end point and the gas is maintained for 5 to 15 seconds. The gas protection is stopped after the material is cooled below the phase change temperature.

10. The laser in-situ welding method based on competitive phase kinetic design for suppressing SiCp / Al interface reaction according to claim 1, characterized in that: The SiCp / Al composite material and the intermediate layer are made of two different materials.

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