Ultrasonic Vibration Assisted Machining Advanced aluminum alloys

Purpose and goal

The project, intended to study the effect of ultrasonic-assisted processing of advanced aluminum alloys. This with respect to machinability, tool wear, and chip forming. By building a demonstrator equipment where one can combine ultrasound and tool cooling with liquid nitrogen under high pressure, 24 bar. Experiments carried out show an increased tool life of over 80 per cent within narrow cutting parameters for the various aluminum alloys. The best results are obtained where a large amount of silicon carbide is added to the aluminum alloy, the SIKA material from AC-Floby.

Expected results and effects

The project built equipment for ultrasonic assisted machining where tool cooling is achieved by supplying liquid nitrogen under high pressure, 24 bar. Experiments carried out with drilling in materials from Hydro and AC-Floby show that tool lives in excess of 80 per cent can be obtained with liquid nitrogen. When machining the aluminum alloy from Hydro, the effect of ultrasound was absent. When aluminum alloy is added to silicon carbide, a similar increase in tool life was demonstrated, the difference being that ultrasound-assisted machining had a clear effect.

Planned approach and implementation

The ultrasonic equipment was first procured, then the equipment for supplying liquid nitrogen under high pressure, 24 bar, was built. Here the challenge was to ensure that the nitrogen was in a liquid state when it reached the tool tip and under 24 bar pressure. The experiments were carried out with drilling operations where tool failure was the criterion for the service life obtained. Parameters studied were cutting speed and feed rate. Based on these parameters, tool life, chip forming and surface finish were evaluated.