Study Of The Action Law Of Ultrasonic On AlTiC Grain Refiner In Casting Process Of Aluminum Alloy

Shape and distribution of solidification structure of castings have a major impact on its combination properties. The article is to study and compare the refining effect of solidification structure under different casting conditions by adding different mass fraction of AlTiC grain refiners in different action time and different power of ultrasonic field in different response time. The research indicates that:1.The effect of refining AlTiC grain refiner brings to Al alloy is obvious, and in a limited extent, the more the AlTiC grain refiners the better the effect. The effect of refining is at its best when the mass fraction of AlTiC is around0.5%; The effect of refining of AlTiC grain refiners is also related to refining time and application time. The research indicates that when the time is between15-20minutes, the refining effect of the refiner is at its best; however, if the refining time continues to extend, the refining effect would be gradually diminished as the refiner begins to lose its refining capability.2.The nucleation ability of TiC particle is closely related to the shape, size and distribution of the particle. The smaller the particle, the stronger nucleation ability of TiC particle will be; the smaller the particle’s surface curvature, the less the minimum of nucleation energy is required, the more the nucleation rate; when the particles agglomerate, the surface of the particle cluster will become irregular, which will enhance the nucleation ability of particle.3.The power of ultrasonic field influences the effect of grain refining. Within a certain range, the larger the power of ultrasonic is, the more obvious the effect of solidification structure refining is; applying ultrasonic vibration near the liquids temperature will increase the number of effective nucleation particle per unit area, and the nucleation rate will also be improved.4.In terms of the refining effect of solidification structure, it is more obvious under the coupling of ultrasonic field and the AlTiC grain refiners than any other singular disposal method for melt; The grain size of the solidification structure is influenced by the enrichment degree of Ti atoms Segregation. When the addition of ultrasonic vibration, ultrasonic cavitation and ultrasound acoustic streaming effect greatly improved the distribution of Ti atoms, reducing the the segregation concentration and area, and eventually activating the AlTiC grain refiner.