CN112760548A

CN112760548A - Automatic secondary feeding method for smelting rare earth alloy

Info

Publication number: CN112760548A
Application number: CN202011581783.9A
Authority: CN
Inventors: 魏中华; 赵栋梁; 张斌洪; 付松; 何杰杰; 黄风
Original assignee: Zhejiang Innuovo Magnetics Industry Co Ltd
Current assignee: Zhejiang Innuovo Magnetics Industry Co Ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2021-05-07

Abstract

The invention discloses an automatic secondary charging method for smelting rare earth alloy, which is characterized in that firstly, iron and other raw materials with melting points far higher than that of rare earth in the rare earth alloy are made into a secondary charging container; then putting raw materials such as rare earth and the like into a secondary charging container, and putting the raw materials and the secondary charging container into a crucible together; other required raw materials are also directly put into the crucible; and finally, smelting all raw materials in the crucible, and after the secondary charging container is melted, enabling the rare earth in the secondary charging container to fall into molten metal in the crucible to realize secondary charging. The invention reduces the volatility and the fluctuation of components, and improves the working efficiency of crucible charging; the auxiliary charging device does not need other mechanisms for assistance, and essentially realizes the effect of secondary charging through primary charging.

Description

Automatic secondary feeding method for smelting rare earth alloy

Technical Field

The invention belongs to the field of rare earth alloy manufacturing, and particularly relates to an automatic secondary feeding method for rare earth alloy smelting.

Background

When the neodymium iron boron is smelted, all raw materials are generally put into a crucible at the same time for smelting. Rare earth has low melting point and is easy to volatilize, so that great loss is caused. Some manufacturers use a secondary feeding mechanism to melt other raw materials such as iron and then add rare earth such as praseodymium and neodymium into the molten metal from above the crucible. In the feeding method in the prior art, the feeding is required to be invested through a mechanism, on one hand, the mechanism action is easy to cause oxygen leakage, and the complexity of operation is increased; on the other hand, alloy liquid sputtering can be generated, so that the raw material formula is inaccurate, and potential safety hazards exist.

Disclosure of Invention

The invention aims to provide an automatic secondary feeding method for smelting rare earth alloy aiming at the defects of the prior art.

The purpose of the invention is realized by the following technical scheme: an automatic secondary feeding method for smelting rare earth alloy comprises the following steps:

(1) one or more raw materials with melting points higher than that of the rare earth in the raw materials for manufacturing the rare earth alloy are made into a secondary charging container according to any proportion;

(2) putting the raw materials to be added secondarily into a secondary charging container, and putting the raw materials and the secondary charging container into a crucible; the raw material needing secondary addition comprises rare earth;

(3) directly putting other required raw materials into the crucible, or putting one part of the raw materials into the crucible directly and piling the other part of the raw materials above the raw materials put into the secondary feeding container in the step (2);

(4) the crucible is used for smelting, and after the secondary charging container is melted, the raw materials fall into molten metal in the crucible, so that secondary charging is realized.

Further, the material of the secondary feeding container is iron.

Further, the raw material to be secondarily added also includes gallium.

Further, the raw material to be secondarily added also includes manganese.

The invention has the beneficial effects that: the invention relates to an automatic secondary feeding method for smelting rare earth alloy, which is characterized in that a container is made of a material with a higher melting point in a formula, and after the container with the high melting point is melted, rare earth falls into a metal solution to realize automatic secondary feeding; thereby reducing the volatility and the fluctuation of components and improving the working efficiency of the crucible during charging; the auxiliary charging device does not need other mechanisms for assistance, and essentially realizes the effect of secondary charging through primary charging.

Drawings

FIG. 1 is a schematic representation of the use of the present invention;

FIG. 2 is a schematic view of the melting furnace of the present invention; wherein (a) is a cross-sectional view, (b) is an internal schematic view, and (c) is a top view;

in the figure: crucible 1, pure iron bucket 2, low-melting-point volatile material 3 such as rare earth, high-melting-point nonvolatile material 4 such as pure iron.

Detailed Description

As shown in fig. 1-2, the automatic secondary feeding method for rare earth alloy smelting of the invention specifically comprises the following steps:

(1) a metal simple substance or an alloy material with a higher melting point in the formula is made into a container, and pure iron is made into a pure iron barrel 2 in the embodiment;

(2) putting part or all of other raw materials needing secondary addition, such as rare earth, gallium Ga, manganese Mn and the like, into a container, and putting the raw materials together at the middle upper part of a crucible, wherein the embodiment adopts a low-melting-point volatile material 3, such as rare earth and the like;

(3) putting all or part of the rest raw materials into the bottom of the crucible 1, and putting high-melting-point and difficult-to-volatilize materials 4 such as pure iron and the like;

(4) if there is any remaining raw material, the stack is placed above the secondary addition raw material contained in the container.

(5) After the container is melted, the rare earth and other materials in the container fall into the molten metal for melting, and secondary feeding is realized during melting.

Examples

The preparation process of the raw materials comprises: nd of 99.5% purity was prepared₇₅Pr₂₅Dy with purity of 99.8%, industrial Fe-B, industrial pure Fe and Co, and Dy with purity of 99.5%Cu, Al and Ga with the purity of 99.999 percent, industrial ZrFe, and ten parts are prepared according to weight percent wt percent. The contents of the elements are shown in table 1:

table 1: contents of respective elements of examples and comparative examples

Wherein, five parts are taken as comparative examples, are respectively and directly put into aluminum oxide crucibles by a conventional method, are smelted in a high-frequency vacuum induction smelting furnace, are refined for 5min at 1500 ℃, are cooled to 1430 ℃ by adjusting heating power, and are cast by a single-roll quenching method, so as to obtain the flappers. And (3) putting the melt-spun sheet into a hydrogen breaking furnace at room temperature, introducing hydrogen with the purity of 99.5%, absorbing hydrogen for 3 hours, vacuumizing while heating, vacuumizing at the temperature of 500 ℃ for 2 hours, cooling, and taking out the powder after hydrogen breaking and crushing. Performing jet milling under nitrogen with oxygen content of less than 100ppm to obtain fine powder, adding methyl octanoate in an amount of 0.10 wt% of the mixed powder, and mixing with V-type blender. After being formed in a press with an oriented magnetic field of 1.8T, the material is placed into a sintering furnace for sintering and aging. Five additional portions were used as examples, using the secondary addition method of the present invention. The magnetic property test was carried out using NIM-62000 rare earth permanent magnet nondestructive measurement system of China's institute of metrology, and the results are shown in Table 2.

Table 2: result of magnetic property detection

From the average values of the results of the comparative examples and examples in table 2, it can be seen that the secondary feeding manner has less rare earth loss in the vacuum melting stage, and the intrinsic coercive force and squareness of the magnet are higher and more stable.

Claims

1. An automatic secondary feeding method for smelting rare earth alloy is characterized by comprising the following steps:

(1) one or more raw materials with melting points higher than that of the rare earth in the raw materials for manufacturing the rare earth alloy are made into a secondary charging container according to any proportion.

(2) Putting the raw materials to be added secondarily into a secondary charging container, and putting the raw materials and the secondary charging container into a crucible; the raw material to be secondarily added includes rare earth.

(3) Other needed raw materials are also directly put into the crucible, or one part of the raw materials is directly put into the crucible, and the other part of the raw materials is stacked above the raw materials put into the secondary feeding container in the step (2).

2. The automatic secondary rare earth alloy melting charging method as claimed in claim 1, wherein the material of the secondary charging vessel is iron.

3. The rare earth alloy melting automatic secondary feeding method as claimed in claim 1, wherein the raw material to be secondarily added further includes gallium.

4. The rare earth alloy melting automatic secondary feeding method as claimed in claim 1, wherein the raw material to be secondarily added further includes manganese.