Zn-Zr intermediate alloy and preparation method and application thereof

Abstract

The invention discloses a Zn-Zr intermediate alloy, which is characterized by comprising the following components in percentage by mass: 0.01-17% of zirconium (Zr) and the balance of zinc (Zn). The invention also discloses a preparation method and an application of the Zn-Zr intermediate alloy. The preparation process is simple, has no pollution and is an environment-friendly production process. The obtained intermediate alloy has an efficient grain refinement effect on primary eta-Zn or primary alpha-Al in hypo eutectic and hypereutectic Zn-Al alloys, and has a lower melting temperature, so that the intermediate alloy can be rapidly melted and uniformly distributed after being added into the Zn-Al alloy in grain refinement, the smelting temperature of the Zn-Al alloy is reduced, the smelting treatment time is reduced, and the production cost is greatly reduced.

Description

technical field [0001] The invention relates to a Zn-Zr master alloy refining agent for refining primary η-Zn or primary α-Al grains in zinc-aluminum alloys and a preparation method thereof, and also relates to the refining process of the Zn-Zr master alloy The application of primary η-Zn or primary α-Al grains in zinc-aluminum alloy belongs to the technical field of metal alloy materials. Background technique [0002] Zinc-aluminum alloy has excellent mechanics, casting technology and mechanical processing performance, and has broad market application prospects. The hypoeutectic zinc-aluminum alloy matrix with aluminum content less than 5wt.% is composed of primary η-Zn grains and Zn-Al eutectic structure, and η-Zn grains are directly formed in the melt, which is easy to form branches Well-developed, large-sized dendrites. However, hypereutectic zinc-aluminum alloys with aluminum content greater than 5wt.% tend to form well-developed primary α-Al dendrites during solidifi...

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Problems solved by technology

[0003] The zinc-aluminum alloy grain refiners commonly used in production are aluminum-based master alloys (such as Al-Sr, Al-Ti master alloys), salts (such as K 2 TiF 6 ), rare earths are common, these refining agents will have many problems in the actual use process: the melting temperature of rare earth and aluminum-based master alloy is much higher than the melting temperature of zinc-aluminum alloy, in order to make the refining agent melt into zinc-aluminum alloy and The distribution is uniform, and the melting temperature or holding time needs to be increased during refining, which will greatly increase the production cost; the aluminum content of zinc-aluminum alloy will change greatly after adding the aluminum-based master alloy refiner, which may cause some Changes in performance (especially for hypoeutectic zinc-aluminum alloys with low aluminum content); the absorption of effective refining elements after salts are added to the zinc-aluminum melt is unstable, so that the addition amount cannot be precisely controlled, and the finer elements Other salt compounds will be produced during the chemical process, which will become inclusions in the zinc-aluminum alloy and deteriorate its mechanical properties.

Moreover, the above refiners only refine the primary α-Al dendrites in hypereutectic zinc-aluminum alloys, and there are very few literatures on the refinement of primary η-Zn grains in hypoeutectic zinc-aluminum alloys. report

[0004] The Chinese invention patent with application number 201010204115.4 provides a method for preparing Zn-Ti master alloy with zinc as the matrix, but this invention requires a relatively high melt reaction temperature (up to 750-880°C), which may lead to partial oxidation of zinc and burn

In addition, in order to promote the melting of titanium and reduce the oxidation and burning loss of zinc, the invention adopts the technological measures of increasing the temperature and adding raw titanium, which brings the problems of complex process and long production cycle

The Chinese invention with application number 201110233071.2 provides a zinc-aluminum-titanium-boron master alloy that can be used to refine primary η-Zn and primary α-Al grains in hypoeutectic and hypereutectic zinc-aluminum alloys , but this invention needs to be prepared with fluoride salts. During the preparation process, toxic gases or solids will be released, which will pollute the environment and damage the health of production workers, increase the production process of waste disposal, and at the same time, the prepared master alloy matrix may contain Solid fluorine salt compounds remain due to incomplete slag removal. Adding such an master alloy to the zinc-aluminum alloy to be refined will reduce its mechanical properties or cause other product quality problems

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