Machining Ultrasonic machining: New toolholders for hard and brittle materials
For manufacturers faced with the challenge of machining hard and brittle materials or companies with difficulties undertaking micromachining operations, Hyfore Workholding has now introduced a new range of ultrasonic tool holders. The ultrasonic tool holders are designed for machining materials ranging from carbide and PEEK through to Zirconia, Sapphire, SiC, AlSiC, Quartz, Boron Nitride and more.
The new ultrasonic tool holders introduced by Hyfore can be retrofitted to virtually any machine tool. By utilising ultrasonic vibrations that resonate at a frequency range of 20 to 60 kHz, the cutting tool oscillates in an upward and downward motion at a frequency of beyond 20,000 times per second. For the end-user, this high-speed frequency exceeds the frequency of sound waves and it can improve tool life and machining performance whilst delivering high-quality surface finishes on difficult materials.
The new system incorporates an ultrasonic generator with automatic frequency detection and tracking unit that is located outside the machine and is connected to an ultrasonic tool holder. The externally connected generator has a 24 kHz frequency with 30 W auto frequency tracking that generates a high-power output that is designed for machine shop environments. This generator is suitable for high precision continuous operations with its integrated electronic circuitry and the ability to automatically switch power supply for AC100-240 V and 50/60 Hz.
Connecting to this externally positioned generator is an ultrasonic tool holder that is available to suit most machine tools with BT30, BT40, HSK63A, CV40 and DV40 connections available. The ultrasonic tool holders have a maximum weight of 2.4 to 3.4 kg depending on connection type and it is recommended the spindles run at a speed of up to 6,000 rpm with a maximum runout of <5 microns. With a frequency of 24 kHz and an amplitude range of 2-10 microns, the high-frequency vibration of 24,000 times per second equates to a machining speed of a staggering 240,000 rpm.
Oscillating at such a high frequency, the Acrow ultrasonic spindles from Hyfore Workholding eliminate the need for specialist high-frequency machine tools for processing the most challenging materials in the industry. Despite being a specialist product application, the Acrow ultrasonic spindles facilitate through spindle coolant and can also work with automatic tool change units, making the system suitable for most machine tools.
According to the company, this versatility affords any machine tool the ability to machine Monocrystalline silicone and ceramic packaging materials used in the semiconductor industry, optical display panel machining and LED substrate machining as well as ceramic bearing, brake pad, cylinder liners and injection nozzles in the automotive industry. The spindles are also suitable for composite, honeycomb and titanium machining in the aerospace sector; ceramic teeth, bone screws and more in the medical sector and it is the perfect problem solver for manufacturers in the micromachining and jewellery industries.