Welding method for titanium boride reinforced aluminum matrix composite

Abstract

The invention relates to the technical field of welding, in particular to a welding method for a titanium boride reinforced aluminum-based composite material, which comprises the following steps of: ensuring that the surface of the titanium boride reinforced aluminum-based composite material to be welded is clean and free of impurities such as oil stains and oxides; heating a welding bead by using heating equipment until the temperature reaches 200-250 DEG C, and completing primary preheating; in the friction stir welding process, the welding bead is secondarily preheated on the front side of the stirring head through the heating equipment, and the secondary preheating temperature ranges from 300 DEG C to 350 DEG C; in the friction stir welding process, cooling equipment is arranged on the rear side of a stirring head to rapidly cool a welded welding bead; after welding is completed, a welding bead is polished; and welding bead quality detection is carried out, and a defect-free welding joint which is good in appearance forming and fine in microstructure can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of welding, and in particular to a welding method for titanium boride reinforced aluminum-based composite materials. Background Art

[0002] Titanium boride reinforced aluminum matrix composite material is a composite material made of aluminum or its alloy as a matrix and titanium boride (TiB2) particles as a reinforcing material.

[0003] Titanium boride reinforced aluminum matrix composites have shown broad application prospects in many fields due to their unique physical and mechanical properties. Titanium boride reinforced aluminum matrix composites are difficult to weld, and conventional welding methods are prone to defects such as pores, inclusions, component segregation and poor weld formation.

[0004] The welding method for titanium boride reinforced aluminum-based composite materials provided in this solution adopts stir friction welding as a new connection method, which can effectively solve the defects such as pores, inclusions, thermal cracks, etc. caused by traditional welding methods and improve the welding quality. Summary of the invention

[0005] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a welding method for titanium boride reinforced aluminum-based composite materials.

[0006] The technical solution adopted by the present invention is as follows: A welding method for titanium boride reinforced aluminum-based composite materials, comprising the following steps:

[0007] Step 1: Preparation before welding:

[0008] Ensure that the surface of the titanium boride reinforced aluminum-based composite material to be welded is clean and free of impurities such as oil, oxides, etc.

[0009] Step 2: Welding preheating:

[0010] The welding bead is heated by heating equipment until it reaches 200-250℃, completing the initial preheating;

[0011] Step 3: Friction Heating Welding:

[0012] During the friction stir welding process, the weld is preheated again by a heating device at the front side of the stirring head, and the secondary preheating temperature is 300-350℃;

[0013] During the friction stir welding process, a cooling device is provided at the rear side of the stirring head to quickly cool the weld after welding;

[0014] Step 4: Post-weld treatment:

[0015] After welding is completed, the weld is polished and the weld quality is inspected.

[0016] Furthermore, the stirring head is welded with a fine needle stirring head having a concave shoulder and a diameter ratio of the shoulder to the root of the stirring needle of 3:1.

[0017] Furthermore, the rotation speed of the stirring head is 2200-3000r / min.

[0018] Furthermore, the welding travel speed of the stirring head is preferably 500-700 mm / min.

[0019] Furthermore, the downward pressure of the shoulder on the stirring head is preferably 0.4-0.6 mm.

[0020] Furthermore, in step three, the cooling device adopts liquid cooling.

[0021] Furthermore, in step 2, the heating method of the heating device used is ultrasonic heating;

[0022] Ultrasonic heating can further remove grease and dirt on the surface of titanium boride reinforced aluminum-based composite materials.

[0023] Furthermore, in step three, the heating method adopted by the heating equipment is gas heating.

[0024] The beneficial effects achieved by the present invention using the above structure are as follows:

[0025] 1. By selecting a suitable stirring head and setting appropriate welding parameters, a defect-free welded joint with good appearance and fine microstructure can be obtained. The TiB2 reinforcement particles are closely combined with the matrix alloy and are evenly dispersed;

[0026] 2. The friction stir weld area of ​​the composite material will have relatively low corrosion resistance in NaCl solution;

[0027] 3. Secondary preheating can improve the fluidity of materials;

[0028] 4. Rapid cooling is beneficial to reduce the loss of mechanical properties of the workpiece after welding and improve the welding coefficient of the weld;

[0029] 5. Ultrasonic heating can further remove grease and dirt on the surface of the material and improve the cleaning effect. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] Embodiment, a welding method for titanium boride reinforced aluminum-based composite material, comprising the following steps:

[0032] Step 1: Preparation before welding:

[0033] Ensure that the surface of the titanium boride reinforced aluminum-based composite material to be welded is clean and free of impurities such as oil, oxides, etc.

[0034] Step 2: Welding preheating:

[0035] The welding bead is heated by heating equipment until it reaches 200-250℃, completing the initial preheating;

[0036] The heating device is heated by ultrasonic heating, which uses the high-frequency vibration and energy transfer characteristics of ultrasonic waves to convert ultrasonic energy into thermal energy. When ultrasonic waves pass through a medium, they cause intense friction and collision between molecules in the medium, thereby generating heat.

[0037] Ultrasonic heating can further remove grease and dirt from the surface of titanium boride reinforced aluminum matrix composites

[0038] Step 3: Friction Heating Welding:

[0039] The stirring head used for friction stir welding is a concave shoulder, and the ratio of the shoulder to the root diameter of the stirring needle is 3:1. When the diameter of the stirring needle shoulder is small, the heat input in the welding area is more concentrated, the plastic flow of the weld metal is better, and a defect-free welded joint with good appearance and fine microstructure can be obtained.

[0040] The preferred stirring needle diameter is 3-4 mm, the needle length is 2.5-5 mm, and the stirring needle shoulder diameter is 9-12 mm. The shape of the stirring head has a great influence on the heat input distribution state of the stirring zone;

[0041] The shoulder pressure on the stirring head is preferably 0.4-0.6 mm, preferably 0.4 mm;

[0042] The rotation speed of the stirring head is 2200-3000r / min;

[0043] Preferably 2500r / min;

[0044] The welding travel speed of the stirring head is preferably 500-700 mm / min;

[0045] Preferably 700 mm / min;

[0046] The weld core area has uniform and fine structure, and the stirring needle speed can obtain a dense, uniform and fine defect-free weld joint;

[0047] As the speed of the stirring head increases, the heat input in the welding zone increases, the plastic flow of the weld metal increases, the arc-shaped pattern spacing on the weld surface decreases, and the weld surface and cross-sectional forming quality are improved.

[0048] During the friction stir welding process, the weld is preheated again by a heating device at the front side of the stirring head, and the secondary preheating temperature is 300-350°C; the heating method of the heating device used for the secondary preheating is gas heating;

[0049] During the friction stir welding process, a cooling device is arranged at the rear side of the stirring head to quickly cool the weld after welding, and the cooling device adopts a liquid cooling method, such as liquid nitrogen;

[0050] The cooling rate is 100-150℃ / S;

[0051] Step 4: Post-weld treatment:

[0052] After welding is completed, the weld is polished and non-destructive testing of the weld quality is performed.

[0053] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A welding method for titanium boride reinforced aluminum-based composite materials, characterized in that: The steps include: Step 1: Preparation before welding: Ensure that the surface of the titanium boride reinforced aluminum-based composite material to be welded is clean and free of impurities such as oil, oxides, etc. Step 2: Welding preheating: The welding bead is heated by heating equipment until it reaches 200-250℃, completing the initial preheating; Step 3: Friction Heating Welding: During the friction stir welding process, the weld is preheated again by a heating device at the front side of the stirring head, and the secondary preheating temperature is 300-350℃; During the friction stir welding process, a cooling device is provided at the rear side of the stirring head to quickly cool the weld after welding; Step 4: Post-weld treatment: After welding is completed, the weld is polished and the weld quality is inspected.

2. A welding method for titanium boride reinforced aluminum-based composite materials according to claim 1, characterized in that: The stirring head is selected to be welded with a fine needle stirring head with a concave shoulder and a diameter ratio of the shoulder to the root of the stirring needle of 3:

1.

3. A welding method for titanium boride reinforced aluminum-based composite materials according to claim 2, characterized in that: The rotating speed of the stirring head is 2200-3000r / min.

4. A welding method for titanium boride reinforced aluminum-based composite materials according to claim 3, characterized in that: The welding travel speed of the stirring head is preferably 500-700 mm / min.

5. A welding method for titanium boride reinforced aluminum-based composite materials according to claim 4, characterized in that: The shoulder pressure on the stirring head is preferably 0.4-0.6 mm.

6. A welding method for titanium boride reinforced aluminum-based composite material according to claim 1, characterized in that: In step three, the cooling device adopts liquid cooling.

7. A welding method for titanium boride reinforced aluminum-based composite material according to claim 1, characterized in that: In step 2, the heating method adopted by the heating equipment is ultrasonic heating.

8. A welding method for titanium boride reinforced aluminum-based composite material according to claim 1, characterized in that: In step three, the heating method adopted by the heating equipment is gas heating.

9. A welding method for titanium boride reinforced aluminum-based composite material according to claim 1, characterized in that: In step 3, the cooling rate is 100-150°C / S.