阅读说明：本技术 一种铝合金复合细化、强化剂及其制备方法和装置 (Aluminum alloy composite refining and strengthening agent and preparation method and device thereof ) 是由 怯喜周 武林 彭艳杰 张帅 邢丹 陈刚 赵玉涛 于 2019-08-30 设计创作，主要内容包括：本发明属金属材料领域,特指一种用于铝及铝合金的复合细化、强化剂及制备方法和装置。首先将纯铝置于熔炼炉坩埚中熔化至一定温度、使铝熔体的顶部超过坩埚中电磁循环装置的上部入口、并在坩埚顶部加入铝合金覆盖剂,将称量并经过预处理的Ti、B<Sub>2</Sub>O<Sub>3</Sub>、Zr、C粉或屑从电磁循环装置的加料口加入,然后启动电磁循环装置,经过一段时间的循环反应复合获得所需的复合细化、强化剂。本发明所制备的复合细化、强化剂,不仅具有传统Al-Ti-B系高效细化、Al-Ti-C系长效细化的特点,而且包含大量亚微米和纳米级的TiB<Sub>2</Sub>、ZrB<Sub>2</Sub>、TiC、ZrC增强体颗粒,在提高细化效果的同时,最终弥散分布于合金基体中起到弥散强化的效果。(The invention belongs to the field of metal materials, in particular to a composite refining and reinforcing agent for aluminum and aluminum alloy and a preparation method and a device thereof.A pure aluminum is firstly placed in a crucible of a smelting furnace to be melted to a certain temperature, the top of an aluminum melt exceeds the upper inlet of an electromagnetic circulating device in the crucible, an aluminum alloy covering agent is added at the top of the crucible, Ti, B 2 O 3 , Zr, C powder or scraps which are weighed and pretreated are added from a charging port of the electromagnetic circulating device, then the electromagnetic circulating device is started, and the required composite refining and reinforcing agent is obtained by compounding through a period of circulating reaction.)

1. The aluminum alloy composite refining and reinforcing agent is characterized by comprising an aluminum-titanium-zirconium-carbon-boron intermediate alloy, and the aluminum alloy composite refining and reinforcing agent comprises the following components in percentage by mass: 85.00-94.50% of aluminum, 2.50-8.50% of titanium, 2.00-3.00% of zirconium, 0.50-1.50% of carbon and 0.50-3.50% of boron.

2. The device for preparing the aluminum alloy composite refining and reinforcing agent according to claim 1 comprises a smelting furnace, and is characterized in that a circulating pipeline is additionally arranged at one side of the smelting furnace, an electromagnetic pump is placed in a corner below the circulating pipeline, a feeding port is arranged above the circulating pipeline, and a secondary valve is arranged in the feeding port.

3. The apparatus of claim 2, wherein said recirculation conduit is made of high purity graphite.

4. The method for preparing the aluminum alloy composite refining and reinforcing agent by using the device as claimed in claim 2 is characterized by comprising the following specific steps:

(1) Putting an aluminum-based material into an electromagnetic circulation integrated device, heating to a certain temperature to melt the aluminum-based material, and then adding an aluminum alloy covering agent to form a covering layer;

(2) Two-stage valves are arranged in the feed inlet, the first-stage valve is opened, pretreated Ti, B ₂ O ₃, Zr and C powder or chips are added into the feed inlet, the first-stage valve is closed, the second-stage valve is opened, and the pretreated Ti, B ₂ O ₃, Zr and C powder or chips fall into the circulating pipeline;

(3) and opening the electromagnetic pump to enable the metal melt to flow circularly through the circulating pipeline, enabling Ti, B ₂ O ₃, Zr and C powder or scraps to be brought into the aluminum alloy melt for reaction and recombination through the circulating pipeline, circulating for a period of time, closing heating after the reaction is finished, closing the electromagnetic pump, slagging off, refining, cooling the melt to a certain temperature, and then casting and molding.

5. The method according to claim 4, wherein the certain temperature in step (1) is 850-1200 ℃.

6. The method of claim 4, wherein the two-stage valve of step (2) is a two-stage valve, and the opening of the valve at different times avoids the Ti, B ₂ O ₃, Zr, C powder or chips from contacting air as they enter the melt.

7. The method of claim 4, wherein the pretreatment in step (2) is drying Ti, B ₂ O ₃, Zr, C powder or chips at 200 ℃ for 2 h.

8. The method of claim 4, wherein the ratio of Ti, B ₂ O ₃, Zr, C powder and swarf in step (2) is 2.7-9.1% titanium sponge, 2-3% zirconium swarf, 0.50-1.50% graphite powder, and 3.2-22.0% boron oxide powder, based on the weight of the composition on the aluminum-based material.

9. The method of claim 4, wherein the cycle time in step (3) is 20 to 30 minutes.

10. The method of claim 4, wherein the cooling in step (3) is performed at a temperature of 720 ℃ to 800 ℃.

Technical Field

The invention belongs to the field of metal materials, and particularly relates to an intermediate alloy of an aluminum-titanium-zirconium-carbon-boron composite refining and reinforcing agent for aluminum and aluminum alloy, and a preparation method and a device thereof.

Background

With the increasing application of aluminum alloy in the high and new technology field, the aluminum alloy with fine and uniform equiaxial grains has wide market application prospect. In industrial production, adding grain refiner into melt is the most economical and practical method for refining grains and improving comprehensive mechanical properties of alloy. The aluminum-titanium-boron intermediate alloy has the characteristic of long-acting refining as the most widely used refiner, can effectively prevent the formation of coarse isometric crystals, columnar crystals and feathered crystals, at present, about 75 percent of aluminum and aluminum alloy in the world adopts the aluminum-titanium-boron intermediate alloy to refine grains, but the main reaction raw material of the aluminum-titanium-boron intermediate alloy is a fluorine-containing compound, so a great amount of fluoride smoke dust is generated in the preparation process of the alloy, and the environment is greatly polluted. The aluminum-titanium-carbon intermediate alloy refiner has the advantages of high refining efficiency and green and pollution-free production, but the carbon has poor wettability in molten aluminum and difficult alloying, thus becoming the bottleneck of large-scale stable preparation.

Disclosure of Invention

The invention aims at the defects that a large amount of fluoride smoke dust is generated in the preparation process of the existing aluminum-titanium-boron refiner, the environment is greatly polluted, and the carbon in the preparation process of the aluminum-titanium-carbon refiner has poor wettability in aluminum liquid and is difficult to prepare; the prepared aluminum-titanium-zirconium-carbon-boron composite refined and strengthened agent intermediate alloy can effectively refine aluminum and aluminum alloy, and simultaneously, a large amount of micro-nano particles in the intermediate alloy are dispersed in the alloy to play an effective dispersion strengthening role.

The electromagnetic circulation composite integrated device designed by the invention has the advantages that on one hand, the covering layer is formed by adding the covering agent, the secondary valve is protected, the loss of reaction components is avoided, and on the other hand, the components are uniform through the continuous circulation of the electromagnetic pump.

The invention adopts an independently designed electromagnetic circulation composite integrated device, which comprises a smelting furnace and is characterized in that a circulation pipeline is additionally arranged on one side of the smelting furnace, an electromagnetic pump is placed in a corner below the circulation pipeline, a charging opening is arranged above the circulation pipeline, and a secondary valve is arranged in the charging opening.

The method for preparing the aluminum alloy composite refining and reinforcing agent by using the device comprises the following specific steps:

(1) Putting an aluminum-based material into an electromagnetic circulation integrated device, heating to a certain temperature to melt the aluminum-based material, and then adding an aluminum alloy covering agent to form a covering layer;

(2) Two-stage valves are arranged in the feed inlet, the first-stage valve is opened, pretreated Ti, B ₂ O ₃, Zr and C powder or chips are added into the feed inlet, the first-stage valve is closed, the second-stage valve is opened, and the pretreated Ti, B ₂ O ₃, Zr and C powder or chips fall into the circulating pipeline;

(3) And opening the electromagnetic pump to enable the metal melt to flow circularly through the circulating pipeline, enabling Ti, B2O3, Zr and C powder or scraps to be brought into the aluminum alloy melt for reaction and recombination through the circulating pipeline, circulating for a period of time, closing heating after the reaction is finished, closing the electromagnetic pump, slagging off, refining, cooling the melt to a certain temperature, and then casting and molding.

The aluminum alloy composite refining and strengthening agent mainly refers to an aluminum-titanium-zirconium-carbon-boron intermediate alloy, and the aluminum alloy composite refining and strengthening agent comprises the following components in percentage by mass: 85.00-94.50% of aluminum, 2.50-8.50% of titanium, 2.00-3.00% of zirconium, 0.50-1.50% of carbon and 0.50-3.50% of boron.

The electromagnetic circulation composite integrated device is a novel smelting furnace which is improved and designed on the basis of a common smelting furnace, and is mainly characterized in that a circulation pipeline with an electromagnetic pump and a charging hole is added to the side surface of the furnace.

The aluminum-based material is generally pure aluminum.

The certain temperature in the step (1) is 850-1200 ℃.

The covering agent in the step (1) is a conventional aluminum alloy smelting covering agent containing a proper amount of cryolite and is commercially available, and the purpose of the covering agent is to isolate the melt from contacting with air.

The two-stage valve in the step (2) is in a double-layer structure as shown in a component 4 shown in fig. 1, and the valve is opened at different time intervals to avoid the Ti, B ₂ O ₃, Zr and C powder or chips from contacting with air when entering the melt.

The pretreatment in the step (2) is to dry Ti, B ₂ O ₃, Zr, C powder or scraps at 200 ℃ for 2 hours.

In the step (2), the ratio of Ti, B ₂ O ₃, Zr, C powder and scrap is sponge titanium accounting for 2.7-9.1%, zirconium scrap accounting for 2-3%, graphite powder accounting for 0.50-1.50% and boron oxide powder accounting for 3.2-22.0% of the aluminum-based material.

The circulation period in the step (3) is 20-30 minutes.

the cooling to a certain temperature in the step (3) is 720-800 ℃.

The circulating pipeline is made of high-purity graphite.

The invention adopts the fluoride-free raw material to avoid the pollution of a large amount of fluoride smoke dust generated in the preparation process of the existing aluminum-titanium-boron refiner to the environment. However, pure titanium powder is easy to oxidize, carbon powder and aluminum liquid are poor in infiltration, and an oxide film is easily generated when the aluminum liquid contacts with air, so that the powder is difficult to add.

The composite refining and strengthening agent prepared by the invention not only has the characteristics of high-efficiency refining of the traditional Al-Ti-B system and long-acting refining of the Al-Ti-C system, but also comprises a large amount of submicron and nanoscale TiB ₂, ZrB ₂, TiC and ZrC strengthening body particles, and the composite refining and strengthening agent is finally dispersed in an alloy matrix to play a role in dispersion strengthening while improving the refining effect

drawings

Fig. 1 is a schematic diagram of an electromagnetic circulation composite integrated device of the present invention: 1 heating gas inlet, 2 covering layers, 3 charging openings, 4 secondary valves, 5 circulating pipelines, 6 electromagnetic pumps, 7 smelting furnaces and 8 discharging openings.

FIG. 2 is an XRD pattern of Al-3Ti-3Zr-1B-1C fining enhancer prepared by adding the present invention.

FIG. 3 is an SEM tissue diagram of Al-3Ti-3Zr-1B-1C fining enhancer prepared by the present invention.

Fig. 4 is a macroscopic structure of an alloy with different refiners 6016 added: (a) before thinning, (B) adding Al-5Ti-1B, (C) adding Al-5Ti-1C, and (d) adding Al-3Ti-3 Zr-1B-1C.

Detailed Description