Ultrasonically Assisted Drawing of Wires, Pipes and Profiles (UAD)
Hielscher Ultrasonics manufactures an ultrasonically vibrating wire die holder that works with standard wire dies of up to 42mm outer diameter. The ultrasonic agitation reduces the line tension required for the diameter reduction significantly. This can be used to increase line speed or to increase the size reduction per drawing step.
With this technology, many materials such as copper, steel or aluminum can be drawn with pure water instead of oil or drawing soap.
Why combine ultrasonics with wire drawing?
The drawing of wire rods requires power to overcome friction and to reshape the material. In a conventional drawing line, this power comes from the rotating capstan, only. The tensile force on the wire rod rises with faster line speed, wire diameter and diameter reduction ratio. Tensile strength and yield strength are critical factors for the drawing of smaller wires, because the ratio of the circumference to cross-section is higher for smaller wire diameters. This limits the drawing line speed and the diameter reduction per drawing step.
The ultrasonically assisted drawing of wires, pipes and profiles reduces the tensile forces and therefore the risk of fractures.
How does ultrasonically assisted wire drawing work?
Ultrasonically assisted drawing transmits a high frequency longitudinal vibration to the wire die. The typical vibration frequency is 20kHz, the wire die displacement can be up to 100 micron (pk-pk). The higher the ratio between the tool’s vibrational velocity and the wire rod speed is, the lower can be the tensile force on the wire line. Therefore ultrasonically powered drawing allows faster drawing line speeds or bigger size reduction in one drawing step for any given tensile stress limit. The reduction in tensile force makes ultrasonically powered drawing most favorable for small material diameters and for hollow strands, such as pipes.
Can I use ultrasonic wire drawing?
The ultrasonically assisted drawing of wires works for line speeds of up to 300m/min (900ft/min). The standard ultrasonic die holder works with wire dies of 25mm and 42mm outer diameter. Ultrasonic die holders for other dimensions are in development and available on request.
Typical wire die inner diameter ranges from 0.01mm to 8mm (AWG#40 to AWG#0).
What Is Required For Ultrasonically Assisted Drawing?
UAD uses your standard wire die. An ultrasonic resonator – also known as sonotrode – replaces the conventional die holder. This sonotrode is a special innovation of Hielscher Ultrasonics. It transmits the ultrasonic longitudinal vibrations efficiently onto the wire die. In order to save installation space, the ultrasonic driver – also known as transducer – agitates the sonotrode from the top. A typical UAD setup requires less than 250mm of line space.
The ultrasonic vibrations are generated by our standard ultrasonic devices, such as: UIP1000hdT (1.0kW), UIP1500hdT (1.5kW), UIP2000hdT (2.0kW) or UIP4000 (4.0kW). These units drive various processes in 24h/7d operations around the world. The power required depends on the line speed, material and the dimensions. The ultrasonic unit are interchangeable, should developments in line speed make more power necessary.
You can retrofit any existing drawing line with an ultrasonic system easily. Many wire line manufacturers are well familiar with the installation or the retrofit of our ultrasonic system. Some of the newer machines have space allocated for the ultrasonic system retrofit, already.
There Are More Wire Rod Processes
- Other applications of ultrasonically assisted wire processing include:
- Ultrasonically Assisted Draw-Peeling of Wire Rods (UADP)
- Ultrasonically Assisted Draw-Cleaning (UADC)
- Ultrasonic Cleaning of Wires, Pipes and Profiles
- Ultrasonic Cleaning of Wire Dies and Extrusion Guides
- Ultrasonic Processing of Metal Melts