Ultrasonic Metal Welding Machine 101

Table of Contents

1. What is an Ultrasonic Metal Welding Machine?

What is Ultrasonic Metal Welding?

Ultrasonic welding is a very popular Metal welding technique. Under the high-frequency(20–40 kHz) vibration pressure, the metal surfaces rub against each other, so that the atoms inside the metal are fully diffused and recrystallized. The wire harness has high strength after welding without changing its own resistance and conductivity.

The welding area is usually 0.2-50mm². The main welding metals are Aluminum wire、copper wires, cable and terminals.

High-frequency ultrasonic acoustic vibrations are locally applied to workpieces being held together under pressure to create a solid-state weld. There will be no metal sparks splashing and oxidation of the weld during welding.

Ultrasonic metal welding machine can perform single-point welding, multi-point welding and short strip welding on thin wire or sheet materials of non-ferrous metals such as copper, silver, aluminum, and nickel.

What is an Ultrasonic Metal Welding Machine?

Ultrasonic metal welding machine also named ultrasonic metal welder and cold metal welding machine. General, the ultrasonic metal welding machine power is divided into 2000W, 3000W, 4000W, and the welding wire harness area is from 0.5mm2-50mm2, which can be welded at one time. 

The integrated design of the whole machine of ultrasonic wiring harness welding equipment, the equipment structure is small in size, light in weight, beautiful in appearance and easy to move; adopts PLL phase-locked frequency automatic tracking technology to ensure the welding effect of wiring harness, cables to terminals;

Ultrasonic wire welding equipment can complete the connection of the wire harness at a small cost; after welding, the conductivity is good, the resistivity is low or almost zero.

See also:

What is an ultrasonic metal welding machine

2. Types of Ultrasonic metal welder

Ultrasonic metal welding machines can be subdivided into ultrasonic spot welders, ultrasonic wire splicing, ultrasonic seam welders and ultrasonic metal tube sealers.

According to the operation mode, it can be divided into the manual model, touch screen model, and PLC model.

3. How does Ultrasonic Metal Welding work?

Composition system

  1. Ultrasonic electricity box: generate electrodynamic high-frequency vibration
  2. Pneumatic part: the main role is to complete the pressure work needs such as pressurization and pressure-holding in the processing process.
  3. Program control part: control the workflow of the whole machine to achieve a consistent processing effect.
  4. Transducer part (Ultrasonic transducer): convert electric vibration into mechanical vibration, after transmission, amplification, to reach the processing surface.
  5. Amplitude modulator: enhances (converts) mechanical vibration.
  6. Weld head: transmits mechanical vibration to the workpiece.
Composition system


During the ultrasonic welding, no electricity or heat is supplied to the metal workpiece; During the welding process, with the help of the static pressure, the vibrational energy at the contact between the two workpieces generates local friction and shear force and produces plastic deformation thus generating heat and the two pieces are joint together at the interface metallurgically upon cooling.

The Working Principle of Ultrasonic Metal Welder

4. Benefits of using Ultrasonic Metal Welding

  1. It saves time. It is much faster than traditional welding methods and saves on manpower.
  2. It saves production costs. Lower production costs and no adhesive needed.
  3. The welding effect is excellent, durable bond, the surface is smooth, and it is clean and hygienic.

See also:

The Advantages of Ultrasonic Welding Processes

5. Are There Limitations/downsides of Ultrasonic Metal Welding Machine

Everything has two sides, and ultrasonic metal welding is no exception. In addition to the advantages that everyone knows, the ultrasonic metal welding machine also has some limitations of its own. 

1. Restrictions on the welding material and thickness

Ultrasonic metal welding requires an exponential increase in power and workpiece thickness and hardness. It is limited to the welding of wires, foils, sheets, and other thin slices. Due to the limitation of the power output capacity of a single sensor, the largest part that can be effectively welded is 250 mm. This length cannot transmit very high power and amplitude control. The ultrasonic metal welding machine requires low water content of the welding material. For materials with high water content, vibration welding is the first choice. If the material is too thick, the ultrasonic welding machine is not an effective method. 

2. Restrictions on the melting point of the welding material

Ultrasonic metal welding machines have certain requirements for the melting points of the two processed workpieces. They need to have the same melting point. Because ultrasonic waves produce the same temperature on the workpiece, it is difficult to fuse together if the two melting points are different. And when the melting point of the welding workpiece exceeds 350 degrees Celsius, it is not suitable to use an ultrasonic metal welding machine.

3. There are some problems in the system

Ultrasonic metal welding machine realizes the cooperation of multiple systems during the welding process, forming a tightly integrated overall system. The system includes an ultrasonic generator, an acoustic system, and a mechanical system. If the coordination degree of the whole system is inconsistent, it will cause some problems in the stability, operability, and reliability of the machine.

4. The mechanism of the ultrasonic metal welding machine is not easy to grasp

The ultrasonic metal welding machine is difficult to manufacture, and its mechanism is not well understood. Because ultrasonic metal welding technology can weld high-density, high-thickness, and dissimilar metals, the realization of this technology puts high demands on the manufacture of ultrasonic metal welding machines. Compared with traditional welding machines, the manufacturing process of ultrasonic metal welding machines is difficult and costly. There are many factors that affect welding process parameters. And it is not easy to understand and summarize the mechanism.

5. “Openness” is poor

The “openness” of the ultrasonic metal welding machine is relatively poor, and its extended size is strictly limited within the welding allowable range. The form of joints is still limited to lap joints, and there is no further breakthrough in technology. The joint form and size range of ultrasonic metal welding is relatively limited.

6. Prone to high-frequency vibration

Ultrasonic metal welders are prone to high-frequency vibration during the welding process, which may cause damage to the edges of the product workpiece, especially hard and brittle materials. 

7. Difficult to detect

In view of the current development status of metal ultrasonic welding machines, it is difficult to inspect the quality of welding products. Its supporting testing equipment has not yet been popularized, and testing methods suitable for traditional welding processes cannot be applied to new processes. If the inspection technology cannot keep up, it is difficult to mass-produce. 

That’s all about the shortcomings of ultrasonic metal welders. Bonne is a well-known manufacturer of ultrasonic metal welding machines in China, providing professional ultrasonic metal welding knowledge and high-quality ultrasonic metal welding machines. If you have any needs, please contact us immediately. 

6. What are the main industries you can use Ultrasonic Metal Welding in?

  • Automotive industry
  • Computer electronics industry
  • Aerospace industry
  • Packaging industry
  • Consumer products industry
  • Medical industry

Ultrasonic metal welding equipment offers advanced processes and controls in a wide range of assembly applications, such as wiring, terminals, battery fittings, cable processing, seam welding, pipe sealing, radiators and coils.


Ultrasonic metal welding is a common technique in automobile wire harnesses, and the principle is to reassemble the surface of the welded material using ultrasonic high-frequency vibrations. Ultrasonic metal welding technology provides a reliable connection to the wiring harnesses inside the vehicle, making the electrical connection system stable and reliable after welding. The low internal resistance and low-temperature rise at the wiring harness joint provide a higher level of safety, especially for new energy vehicles with fast charging and temperature rise.

see also:

Applications of the ultrasonic metal welding machine

7. Which Materials are Suitable for Ultrasonic Welding?

Ultrasonic welding can be used to bond a wide variety of soft, conductive non-ferrous metals ranging from copper, aluminum and nickel, to lithium, brass, silver and gold. Thin plates, thin rods, wires, sheets, and tapes can be welded instantly.

Diagram of welding possibilities between metals

Diagram of welding possibilities between metals

Common welding types:

  1. Nickel-hydrogen batteries nickel-hydrogen batteries nickel mesh interfuse with nickel sheet.
  2. Lithium battery, polymer battery copper foil interfuse with nickel sheet interfusion, aluminum foil, and aluminum sheet.
  3. Wire interfusion, bias knotted into one with multiple interfusion.
  4. Wire interfuse with a variety of electronic components, joints, connectors.
  5. Various household appliances, automotive products, large heat dissipation seat, heat exchange fins, honeycomb heart of the interfusion.
  6. Electromagnetic switches, fuseless switches and other high-current contacts, interfusion of different metal pieces.
  7. Sealing of metal pipes, cutting off water-proof and air-tight.

More detail:

Metals suitble for ultrasonic metal welding

8. Pros and Cons of the Different Types of Welding

Comparison of the four techniques:

Welding processWelding principlesAdvantagesDisadvantages
Pressure weldingAlso known as solid state welding, the two workpieces are bonded interatomically in the solid state under great pressure. The commonly used pressure welding process is resistance butt welding. When the current passes through the joint end of the two workpieces, the temperature right there rises due to the high resistance. When heated to a plastic state, two workpieces joint together under axial pressure.No filler is needed. No melting process. Fast crimping process. production. Light equipment.There is a risk of metal stamping backlash and the risk of oxidation and rusting in harsh working conditions, all of which can lead to poor contact.
Fusion weldingThe workpiece interface is heated to a melt and the weld is completed without pressure.Able to weld different metals together. The weld tumor on the joint of the wiring harness is highly resistant, which greatly reduces the service life of the harness. Defects such as porosity, slag and cracks easily formed in the weld, will deteriorate the quality and performance of the weld.
BrazingUse a metal with a lower melting point than the workpiece as the filler material. The filler material is heated to a temperature between the melting point of the workpiece and the filler material. Then, the filler becomes liquid and fills the interface gap and achieves inter-atomic diffusion with the workpiece to form the weld.Less distortion and precise dimension. Able to weld different metals together. The joint is of low strength. The quality of the weld is affected by the welding filler materials. Overheating, embrittlement, hardening or softening may occur in the weld and heat-affected zone after welding, degrading the performance of the weld.
Ultrasonic weldingThe physical effect created by the ultrasonic vibrations instantly melts the workpiece molecules and binds the wires together.Good welding results and low welding costs. Avoid the risks associated with pressure welding. The electric resistance of the weld is extremely low, close to zero.The ultrasonic welding equipment is relatively more expensive. 

See also:

What is the best welding process for automotive wiring harnesses?

The Types of Ultrasonic Metal Welding Processes

9. Operation Method of Ultrasonic Metal Welding Machine

  1. First, check whether the protective cover of the ultrasonic metal welding machine is intact and whether the screws are loose.
  2. Check the power supply of the whole machine, all normal before putting it into use.
  3. Check whether there is any oxide on the contact surface between the ultrasonic mould and the increased device, and clean it up.
  4. Open the power switch, open the air source switch. Check whether there is any air leakage in the pneumatic system, and open the power and control buttons of each machine head as required.
  5. Check that the parameters (pressure, time, temperature) and action speed and positioning plate position meet the requirements and adjust the positioning scale.
  6. For one size, first press the positioning buttons of the two heads, then place the profile and adjust the position of the head (so that the two ends of the profile will be on the rear positioning plate and the active positioning block) and lock the handle. When welding the same size for the second time, but the profile in and press the positioning button to make it positioned.
  7. After checking that everything is normal (whether the profile is well pressed, whether the temperature is normal, etc.), press the automatic welding button and the welding process will be completed automatically until the welded semi-finished or finished products are taken out after the reset.
  8. After passing the quality inspection of the test welded products, the variable parameter values are locked and can be put into high-efficiency production.
  9. If the hand is pressed by the ultrasonic metal welding machine or the profile blocks the welding plate during the operation, press the emergency stop button to stop the action. Press and then rotate to the right to reset.
  10. After work is completed, close the gas switch and release the remaining gas and water in the triplex.
  11. Turn off the heating and control power supply of each head, and then turn off the general power supply of the equipment.

See also:

Operating instructions for ultrasonic welding machines

4 steps to a successful ultrasonic welding machines assembly

Operation process

The Types of Ultrasonic Welding Methods Spot Welding

The Precautions of Operating Ultrasonic Metal Welding Machine

10,How to Choose Ultrasonic Metal Welder

  1. Select according to the characteristics
    1. Welding materials do not melt, not fragile metal properties.
    2. Good electrical conductivity after welding; the resistance coefficient is extremely low or nearly zero.
    3. low requirements for welding metal surface, oxidation, or plating can be welded.
    4. Short welding time, without any flux, gas, solder.
    5. Welding without sparks, environmental protection, and safety.
  1. Select according to the applicable product selection.
  1. Whether the size of the machine is appropriate.
    1. Whether the ultrasonic metal welding machine fits the size of your parts.
    2. According to the quantity you need, whether the size of the machine can be perfectly placed in your own space.

See also:

How to select the ultrasonic metal welding machine

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