Ultrasonic metal melt treatment system uses the cavitation effect of ultrasonic in the melt to cut and destroy dendrites, impact the solidification front, increase stirring diffusion, homogenize the structure, increase the tensile strength of metal materials and improve the toughness of metal. Fine grain and large boundary area can effectively prevent dislocation and intergranular slip, that is to say, greater force is needed to fracture the material. The finer the grain, the smaller the dendrite spacing, the higher the yield strength and the better the hardness.
The ideal ingot structure is that there are uniform and fine equiaxed crystals on the whole section of the ingot. This is because the anisotropy of equiaxed crystals is small, the deformation is uniform during processing, the performance is excellent and the plasticity is good, which is conducive to casting and subsequent plastic processing. At present, the best way to obtain this kind of structure is to use ultrasonic metal melt equipment to refine the melt.
Function of ultrasonic metal melt treatment system
Removing impurities: it is very difficult for small inclusions in liquid steel to float up. Only when they gather will it be easier to float up. Using ultrasonic metal melt equipment to add ultrasonic into the solution, the ultrasonic standing wave can make the inclusion powder in the solution delamination and agglomeration successfully.
Ultrasonic degassing: ultrasonic has a great effect on removing gas from molten metal. Ultrasonic elastic vibration can completely degass the alloy in a few minutes. When the ultrasonic vibration is introduced into the molten metal, it is found that there is cavitation phenomenon, which is due to the cavity generated after the continuity of the liquid phase is broken, so the gas dissolved in the liquid metal concentrates in it. The elastic vibration of ultrasonic wave promotes the generation of bubble core and makes it grow continuously until it grows to the size that can be smoothly discharged from the molten metal.
Improve slab quality: ultrasonic metal solution equipment can act on the crystallizer to improve the surface quality of slab. The vibration of the mold by ultrasonic can be used for billet, bloom and slab, and there is no negative sliding when ultrasonic vibration is used. When casting billet and bloom, a very smooth billet surface can be obtained after applying ultrasonic vibration to the mold.
Grain refinement: when producing castings by ultrasonic vibration solidification method, the ultrasonic wave will produce positive and negative alternating sound pressure and form jet. At the same time, due to the nonlinear effect, it will produce sound flow and micro sound flow, while ultrasonic cavitation will produce high-speed micro jet at the interface between solid and liquid. The cavitation effect in ultrasonic liquid can cut off and destroy dendrites, impact the solidification front, increase the effect of stirring and diffusion, and purify the structure, refine the grain and homogenize the structure. In addition to the mechanical damage of dendrites caused by vibration, another important role of ultrasonic vibration solidification is to improve the effective undercooling of liquid metal and reduce the critical nucleus radius, so as to increase the nucleation rate and refine the grains.