20Khz 1000w Ultrasonic Aluminum Molten Metal Treatment System With Titanium Horn

20Khz 1000w Ultrasonic Aluminum Molten Metal Treatment System

Parameter

Description

Power ultrasound in molten metals and alloys has shown various beneficial effects such as structuring, degassing and improved filtration. Ultrasound promotes non-dendritic solidification of liquid and semi-solid metals. Sonication has significant benefits for microstructural refinement of dendrites and primary intermetallic particles. Furthermore, power ultrasound can be purposefully used to reduce metal porosity or create mesoporous structures. Last but not least, power ultrasound improves casting quality.

Ultrasonic Solidification

The formation of non-dendritic structures during solidification of metal melts influences the material properties such as strength, ductility, toughness, and/or hardness. Ultrasonically altered grain nucleation: Acoustic cavitation and its intense shear forces increase the nucleation sites and number of nuclei in the melt. Ultrasonic treatment (UST) of melts result in a heterogeneous nucleation and the fragmentation of dendrites, so that the final product shows a significantly higher grain refinement. Ultrasonic cavitation causes the even wetting of non-metallic impurities in the melt. Those impurities turn into nucleation sites, which are the starting points of solidification. Because those nucleation points are ahead of the solidification front, the growth of dendritic structures does not occur.

Sonocapillary Effect during Filtration

The ultrasonic capillary effect (UCE) in liquid metals is the driving effect to remove oxide inclusions during the ultrasonically-assisted filtration of melts. Filtration is used to remove non-metallic impurities from the melt. During filtration, the melt passes various meshes (e.g. glass fibre) to separate unwanted inclusions. The smaller the mesh size, the better is the filtration result.
Under common conditions, the melt cannot pass a two-layered filter with a very narrow pore size of 0,4-0,4mm. However, under ultrasonically-assisted filtration the melt is enabled to pass the mesh pores due to the sonocapillary effect. In this case, the filter capillaries retain even nonmetallic impurities of 1–10μm. Due to the enhanced purity of the alloy, the formation of hydrogen pores at the oxides is avoided, so that the fatigue strength of the alloy is increased.

Ultrasonic Reinforcement

Ultrasonication is proven to be highly effective on dispersing nano particles uniformly into slurries. Therefore, ultrasonic dispersers are the most common equipment to produce nano-reinforced composites.
Nano particles (e.g. Al2O3/SiC, CNTs) are used as reinforcing material. The nano particles are added into the molten alloy and dispersed ultrasonically. The acoustic cavitation and streaming improves deagglomeration and wettability of the particles, resulting in an improved tensile strength, yield strength, and elongation.