Sheet metal joining refers to the process of connecting different sheet metal parts through specific techniques during sheet metal manufacturing, aiming to achieve the functionality and performance of the overall structure.
Sheet metal joining technology is widely used in sectors such as mechanical engineering, chemical engineering, automotive, aerospace and household appliances. The main methods of joining sheet metal include welding, riveting, threaded connections and adhesion.
Welding is one of the most common and crucial methods for joining sheet metal. It achieves a durable connection by heating the parts as a whole or partially, or by inducing plastic deformation in the parts.
Welding methods include TIG welding, spot welding and CO2 gas shielded welding. Among them, TIG welding does not require flux, requires high precision, but can produce high-quality and robust welded joints. Different welding methods generate different temperature fields and thermal deformations, making the choice of an appropriate welding method critical to controlling part deformation.
In addition to welding, metal sheets can be joined using rivets and threaded connections. Riveting is an irreversible connection method, typically used for lightweight or temporary connections. Threaded connections use mechanical elements such as screws and nuts to obtain the connection, suitable for situations that require frequent disassembly.
When choosing a method of joining sheet metal, one must consider factors such as the material properties, the structural design of the connection area and the anticipated conditions of use.
Furthermore, with technological advances, new connection methods such as pressure joining are being researched and applied, with the aim of improving connection efficiency and quality while at the same time reducing costs and time.
Basics of Joining Sheet Metal
Joining metal sheets is an essential process in the manufacture of various products and structures using sheets. It involves connecting or attaching multiple sheets of metal to create a desired shape or form. This process is commonly used in industries such as automotive, aerospace, construction, and appliance manufacturing.
There are several methods and techniques for joining sheet metal, each with its unique advantages and limitations. Some common methods include mechanical fastening, welding, gluing, and soldering. The choice of technique depends on factors such as the type of materials, the application and the required strength of the joint.
Mechanical fixation
A popular method for joining sheet metal because it is quick and simple. It involves the use of hardware such as screws, rivets and bolts to connect the sheets and can be easily dismantled if necessary. This method is suitable for a wide range of materials and thicknesses.
Welding
It involves heating the surfaces of metal sheets to join them together and form a fusion bond. This method provides a robust and durable connection and is commonly used for applications that require high joint strength. Some common welding techniques for sheet metal include resistance spot welding, gas metal arc welding, and laser welding.
Adhesive bonding
A technique that uses special adhesives to join metal sheets. This method is advantageous for joining different materials and relatively thin sheets. Adhesive bonds also provide a smooth, aesthetic appearance and can redistribute tension across the joint.
Weld filler
It is a process that uses a filler material, or solder, that is melted and applied to the joint surfaces to create a bond. Capillary action helps the solder flow and forms a connection between the sheets. Welding is often used for applications that cannot withstand high temperatures and require a low voltage connection.
Selecting the appropriate joining technique requires consideration of several factors such as material compatibility, joint strength requirements, and cost. Additionally, proper surface preparation, joint design, and process control are crucial to ensuring a successful sheet metal joining process.
In conclusion, sheet metal joining plays a vital role in today's industrial world. The industry continually develops new techniques and technologies to meet the specific needs and challenges associated with joining sheet metal, ultimately improving the quality, durability and performance of final products.
Sheet metal joining methods
1. Folding/flap joint
Sheet metal parts can be connected to each other by bending or bending tabs in the form of a buckle and a fastening groove. This assembly method is simple and convenient, resulting in quick assembly.
However, it may not guarantee complete positioning and additional auxiliary positioning may be required.
2. Pulling R Ivet
Riveting is carried out in the hole corresponding to the two parts, and a rivet gun is used to pull the rivet, expanding and deforming the outer rivet sleeve to fix the two parts.
This connection is simple, convenient and fast.
3. Elf -conqueror
Self-riveting is a method that uses mutual deformation between sheet metal parts to achieve mutual fastening.
Although this method is simple, it is often used in applications where disassembly is not necessary.
4. Screw/fastener joint
Self-tapping refers to the process of using self-tapping screws to create threads directly into a sheet metal part, resulting in a tight fit and disassembly capability.
5. Pressing Rivet
The pressure riveting process involves pressing a nut or bolt against sheet metal, which can then be mated to a corresponding external nut or bolt.
6. Welding joints
The main purpose of spot welding is to create a row of weld joints on two pieces of sheet metal.
This is achieved by melting the local sheet metal material in the welding head to complete the connection between the sheet metal parts.
In the above content, we have introduced various sheet metal joining methods.
Finally, a table is used to summarize the advantages and disadvantages of each joining method.
| Joining methods | Tools used | Pros | Cons |
|---|---|---|---|
| Folding joints/flaps | none | 1. Low cost 2. Quick assembly |
It is not possible to completely limit all degrees of freedom, other clamping devices are required |
| Pulling Rivet | rivet gun | 1. Easy to operate, good fluidity 2. Self-positioning |
1. Need to pre-drill 2. The pull pin will have a protrusion 3. There is a limit to the use space of the rivet gun |
| Self-conquerable | dedicated mold | Self-guided, no positioning required | 1. Need to carry out the countersinking process 2. Do not disassemble 3. Yield rate is difficult to guarantee |
| Screw Joint/Fasteners | Screwdriver | Low cost, detachable | Limited number of disassembly |
| Pressing Rivet | dedicated equipment | 1. Safe and reliable 2. Removable |
Higher cost |
| Welding Joints | spot welding machine | 1. Simple process 2. No pre-processing required |
1. Equipment complexity 2. Weak welding strength, welding easy to remove 3. Unable to remove 4. Welding materials must match |
What are the working principles and advantages of new sheet metal connection technologies such as pressure connection?
New sheet metal connection technologies, such as pressure connection, mainly achieve the joining of sheet metal parts through the application of pressure. The working principle of this technology can be referred to the principle of friction welding, that is, the frictional heat generated by pressure and relative movement between the contact surfaces of the welds causes the contact surfaces to melt and combine.
Although friction welding is mentioned here, the basic principle of pressure connection is similar, that is, promoting the connection of materials through the application of pressure.
The advantages of pressure connection mainly include:
- High reliability: By physically pressing materials directly, it reduces defects that welding or other chemical reactions can cause, thus increasing the reliability and durability of the connection.
- Strong adaptability: The pressure connection is applicable to a variety of different materials and shapes, including sheet metal parts, making it incredibly flexible and widely used in industrial applications.
- Easy operation: Compared with traditional welding methods, the operation of pressure connection is simple, not requiring complex equipment or specialized skills, thus reducing production costs and operational difficulty.
- Environmental Protection: As it does not involve the generation of harmful gases, pressure connection is a more environmentally friendly form of connection, meeting current environmental protection requirements.
How do you select the most suitable sheet metal joining method based on material properties?
Selecting the most appropriate sheet metal joining method requires initial consideration of material characteristics, which include comprehensive performance, cost, material performance and processability. Connection methods commonly used in sheet metal processing include welding and riveting, each with distinct characteristics and application scenarios.
- Welding: Welding is a method that connects metals by fusing them using heat, suitable for various applications. Provides high resistance connections, especially for load-bearing structures. Welding techniques such as shielded metal arc welding and tungsten inert gas welding are suitable for scenarios that require high precision and strength in connections.
- Riveting: Riveting is a method of connecting two or more plates using rivets. It can provide good sealing and shock resistance, suitable for light structures or situations that require frequent disassembly.
When choosing a connection method, consider the following factors:
- Design Principles and Best Practices: An in-depth understanding of design principles and best practices is crucial to ensuring the success of sheet metal fabrication projects.
- Manufacturing Process: Understanding the fundamentals of sheet metal fabrication can help determine which technique is best suited for a specific project.
- Balance between cost and performance: The correct choice of materials has a significant impact on the cost, performance and quality of the product.
Choosing the most suitable sheet metal joining method requires comprehensive consideration of material characteristics, design requirements, economics and processability. By comparing the characteristics and application scenarios of welding and riveting, and considering the specific project requirements and material properties, the most suitable choice can be made.
What are the latest research advances in sheet metal connection technology to improve mechanical performance?
The latest research advances in sheet metal connection technology to improve mechanical performance mainly include the following aspects:
Lightweight structures manufacturing technology:
With increasing requirements for material properties in areas such as aerospace, weight reduction has become an important research direction. Sheet metal parts, as key components of alloy sheet connections, have become one of the hot spots of research at home and abroad. This includes the application progress and development trend of superplastic diffusion forming/bonding technology, which can effectively realize the manufacturing of lightweight structures.
Precision sheet metal forming technology:
In the manufacture of advanced sheet metal wall panels for aircraft, the application of precision sheet metal forming technology is an important means to improve mechanical performance. This involves several stages, including sheet metal, heat treatment, machining, connection and surface treatment, and is one of the key technologies in the large aircraft body structure and manufacturing process.
Flare-free internal rolling connection technology:
This is a new type of connection technology that has been applied in the developing state of aerospace metal parts forming technology. This technology can improve the mechanical performance of the connection area, especially in applications that require high resistance connections.
High pressure gas bulging forming technology for titanium alloy sheet metal components:
This technology is mainly used in the research progress of aerospace titanium alloys and their precision forming technologies. Through high-pressure gas bulging forming technology, precision forming of titanium alloy sheet metal components can be realized, thereby improving their mechanical performance.
