Device for ultrasonic melt treatment of light alloys

 

(57) Abstract:

The invention relates to the field of metallurgy and can be used to obtain ingots of aluminum alloys and cast shapes samachisa silumins piston group. The technical result of the invention is the stability of the resonant mode ultrasound radiation in the melt and increased cavitation resistance during continuous operation of the device, leading to the metal with the desired properties. The technical result is achieved in that the device for ultrasonic treatment of the melt contains a magnetostrictive transducer, a concentrator of ultrasonic vibrations and the emitter is made of niobium, tantalum or their alloys, with working part of the radiator is covered with a layer treated with ultrasonic cavitation mode of the aluminum. In addition, the mode of longitudinal vibration of the emitter is made of annealed rods with a length that is a multiple of 1/2 the wavelength of the longitudinal vibration of the ultrasound at the frequency of excitation, and mode of bending vibration of the emitter is made of annealed sheets or plates with a length that is a multiple of 1/2 the wavelength of the Flexural vibrations of ultrasound at a frequency f is used when obtaining ingots of aluminum alloys and cast shapes samachisa silumins piston group.

The closest analogue is the device for ultrasonic melt treatment of light alloys, consisting of a magnetostrictive transducer, the concentrator of ultrasonic vibrations and emitter, made in the form of a ring together with the Gating funnel (USSR author's certificate 973233, C 22 F 3/02, from 15.11.1982).

A disadvantage of this device is the low efficiency of radiation of ultrasound in the melt. Gating funnel is attached mass to the vibrating system, which complicates the calculation of the vibrating system at the resonant frequency, and does not allow to fine-tune all of the ultrasonic device at the resonant mode. These drawbacks of this device does not provide an efficient transfer of ultrasonic energy into the melt. It is not possible to create a sustainable mode of ultrasonic treatment in the process of continuous casting ingot and thereby to provide a uniform structure of the ingot along its length and to improve the quality of the metal.

A device for ultrasonic treatment of light alloys, consisting of a magnetostrictive transducer, the concentrator of ultrasonic vibrations and an emitter made of neither is egime developed cavitation aluminum.

To operate in the longitudinal mode oscillation emitter made of annealed hot-pressed rods of length multiple of half the wavelength of the longitudinal vibration of the ultrasound at the frequency of excitation.

For mode of bending vibration of the emitter is made of annealed sheets or plates whose length is a multiple of half the wavelength of the Flexural vibrations of the ultrasound at the frequency of excitation.

The proposed device for ultrasonic melt treatment of light alloys differs from the closest analogue of the fact that the emitter is made of niobium, tantalum and their alloys, with working part of the radiator is covered with a layer treated with ultrasonic cavitation mode of the aluminum. The proposed device provides transmission of ultrasound from a transducer directly into the melt.

For mode of longitudinal vibration of the emitter is made of annealed hot-pressed rods of length multiple of half the wavelength of ultrasound at the frequency of excitation.

For mode of bending vibration of the emitter is made of annealed sheets or plates.

The technical result is the stability of the resonant mode radiation of ultrasound in repl is the lia with the desired properties.

The proposed device provides all link at the resonant frequency. The surface of the emitter in contact with the cavity melt, almost destroyed, because the diffusion of aluminum into niobium, tantalum and their alloys is extremely small, which excludes the formation at the boundary of contact with the melt brittle and hard aluminides. The emitter retains its elastic properties (young's modulus) when heated from room temperature to the temperature of the treated melt.

All this increases the resistance of the emitter and stability of the resonant mode ultrasound radiation in the melt, allowing to obtain a uniform structure throughout the length of the ingot and thereby improve the quality of the metal.

The invention is illustrated in the drawing, where

in Fig.1 shows the proposed device for the longitudinal modes;

in Fig.2 shows the proposed device for operation in the mode of bending vibration.

The proposed device for ultrasonic melt treatment of light alloys consists of a magnetostrictive transducer (1), the concentrator of ultrasonic vibrations (2) emitter (3) made of niobium, tantalum and SP the representatives of longitudinal vibrations of the annealed hot-pressed rods of alloy of niobium with 5% molybdenum, and the emitters of the annealed hot-rolled plates of technical niobium. In addition, the tool-emitter longitudinal vibrations was made of technical titanium (prototype).

In crucible furnaces were preparing a melt of aluminum of high purity (99,99%) weighing up to 1 kg At a temperature of 700-750oWith held ultrasonic melt treatment at a frequency of 18 kHz using emitters longitudinal vibrations of the annealed rods of length1/2the wavelength of the ultrasound, equal to niobium and its alloys 100 mm and for technical titanium 140 mm

In addition, conducted ultrasonic treatment using emitter Flexural vibrations of technical niobium, made of annealed plates, the tool length is a multiple of 1/2 the wavelength of the Flexural vibrations that at a frequency of 18 kHz is 12 mm

The results of chemical analysis of aluminium after ultrasonic treatment (RCD) from 2 min to 100 h using emitters from technical niobium, niobium alloy with 5% molybdenum and technical titanium (analog) are presented in table. 1.

Investigated the effect of temperature on the change in the elastic properties (young's modulus) at a heating radiators made of different materials from room temperature to 1000o(PL. 2).

Thus, h is its raison d'ętre in the aluminum melt and retains stabilnego elastic properties (young's modulus) in a wide temperature range - from room temperature to the operating temperature of the melt. All this allows to increase the operational reliability of the device, allowing you to keep working mode processing in the process of continuous casting of an ingot.

1. Device for ultrasonic melt treatment of light alloys containing magnetostrictive transducer, the concentrator of ultrasonic vibrations and the emitter, wherein the emitter is made of niobium, tantalum or their alloys, with working part of the radiator is covered with a layer treated with ultrasonic cavitation mode of the aluminum.

2. The device under item 1, characterized in that mode of longitudinal vibration of the emitter is made of annealed rods with a length that is a multiple of 1/2 the wavelength of the longitudinal vibration of the ultrasound at the frequency of excitation.

3. The device under item 1, characterized in that mode of bending vibration of the emitter is made of annealed sheets or plates with a length that is a multiple of 1/2 the wavelength of the Flexural vibrations of the ultrasound at the frequency of excitation.

 

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