Ultrasonic Degassing in Molten Metals & Molten Glass up to 1,800° C

Ultrasonic Degassing in Molten Aluminium

Ultrasonic treatment of metal melts can substantially improve the properties of castings, in particular, their microstructure and mechanical properties. Recently, new refinements to the technique using proprietary ultrasound  technology provide significant benefits to industrial continuous casting, offering an alternative to argon degassing, replacement of standard master alloy additives, and substantial improvements to microstructure. 

Ultrasonic Grain Refinement in Molten Aluminum

Various techniques are available for enhancing the microstructure and grain refinement in aluminium alloys, magnesium, zinc, copper for instance, there is a strong correlation between grain size and casting temperature; however, significant improvements can be achieved using ultrasonic treatment. Two mechanisms contribute to this process.

During the high-pressure cycle of the cavitation process, collapsing bubbles result in localised high temperatures and pressures. Temperatures can exceed 1000 K while pressures can exceed 400 MPa;  rapid cooling rates also occur. The effects of this are twofold: many nucleation sites are formed inducing finer grain sizes, and the energies generated destroy dendritic structures that would otherwise form.

Ultrasonic Micro-Alloying in Molten Aluminium

Our novel ultrasonic melt treatment of aluminium melts using a cavitation frequency of 20 kHz can radically improve the microstructure of the final products. However, when combined with micro-alloying, the results are even more dramatic. Our ongoing ultrasonic microalloying project has already allowed us to create aluminium micro-alloys stronger than steel.

Our work indicates that ultrasonically assisted micro-alloying is opening new ways to the development of next generation automotive alloys.

Ultrasonic Molten Glass Process Energy Savings up to 20%!

There is a strong correlation between bubble size, refining temperature, and time. Simply expressed, larger bubbles rise faster than smaller bubbles; higher refining temperatures reduce the viscosity of the molten glass; bubbles rise more quickly when the viscosity is lower. Thus, to improve the efficiency of the refining process, we would like to increase the bubble diameter and/or reduce the viscosity of the molten glass. As we shall see, ultrasonic refining allows us to increase bubble size and remove bubbles efficiently without the need to raise the temperature of the molten glass.