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Preparation method of molybdenum plate blank

A slab and lanthanum-molybdenum technology, which is applied in the field of preparation of lanthanum-molybdenum slabs, can solve the problems of poor formability, poor formability of doped molybdenum powder, and difficulty in accurately controlling lanthanum content, and achieve stable rolling processing performance and low lanthanum content. Accurate and controllable, the effect of precise and controllable lanthanum content

Active Publication Date: 2020-02-28
ZIGONG CEMENTED CARBIDE CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The first method is that ammonium paramolybdate solution is formulated into ammonium paramolybdate solution, and then ammonium paramolybdate is obtained through evaporation and crystallization. During the evaporation and crystallization process, segregation is very easy to occur, which affects the uniformity of the components and even affects the quality of the product.
Its two, when adding the filtered lanthanum nitrate solution, and making doped ammonium paramolybdate through suction filtration and dehydration, part of the lanthanum nitrate solution will be lost together with the mother liquor during suction filtration, so that the mixed lanthanum The content is difficult to control accurately; in addition, the doped molybdenum powder obtained by using ammonium paramolybdate as the raw material has poor formability, and a molding agent needs to be added when pressing the blank
Therefore, the method has problems such as difficulty in accurately controlling the effective amount of rare earth lanthanum, large waste, poor uniformity of each component in the powder, and poor formability.
[0005] In summary, the method of doping the rare earth lanthanum element into molybdenum has a great influence on the quality of the obtained lanthanum-doped molybdenum slab. In the prior art, there are generally problems such as uneven doping of lanthanum element, uncontrollable doping amount, Unstable product performance and other issues

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  • Preparation method of molybdenum plate blank
  • Preparation method of molybdenum plate blank
  • Preparation method of molybdenum plate blank

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Embodiment 1

[0034] The present embodiment provides a kind of preparation method of molybdenum slab, comprises the following steps:

[0035] Step 1. Place molybdenum dioxide powder and lanthanum nitrate solution in a double-cone vacuum spray doping mixing dryer, mix for 180 minutes under a vacuum condition of 0.04Mpa, and then dry to obtain lanthanum-doped molybdenum dioxide powder, wherein, The lanthanum content in lanthanum-doped molybdenum dioxide powder is 1.5%, the Fischer particle size of molybdenum dioxide is 7μm, and the bulk density is 1.10g / cm 3 .

[0036] Step 2. The lanthanum-doped molybdenum dioxide powder is subjected to hydrogen reduction and sieving to obtain lanthanum-doped molybdenum powder. The hydrogen reduction temperatures are 900°C, 950°C, 990°C, and 1020°C respectively, and the total reduction time is 7 hours; A 200-mesh sieve was used to obtain lanthanum-doped molybdenum powder with an average Fischer particle size of 3.2 μm;

[0037] Step 3. Put the lanthanum-do...

Embodiment 2

[0039] The present embodiment provides a kind of preparation method of molybdenum slab, comprises the following steps:

[0040]Step 1. Place molybdenum dioxide powder and lanthanum nitrate solution in a double-cone vacuum spray doping mixing dryer, mix for 150 minutes under a vacuum condition of 0.04Mpa, and then dry to obtain lanthanum-doped molybdenum dioxide powder, wherein, The lanthanum content in lanthanum-doped molybdenum dioxide powder is 1.13%, the Fischer particle size of molybdenum dioxide is 9 μm, and the bulk density is 1.20 g / cm 3 .

[0041] Step 2. The lanthanum-doped molybdenum dioxide powder is subjected to hydrogen reduction and sieving to obtain lanthanum-doped molybdenum powder. The hydrogen reduction temperatures are 900°C, 950°C, 970°C, and 990°C respectively, and the total reduction time is 7 hours; A 200-mesh sieve was used to obtain lanthanum-doped molybdenum powder with an average Fischer particle size of 3.5 μm;

[0042] Step 3. Put the lanthanum-d...

Embodiment 3

[0044] The present embodiment provides a kind of preparation method of molybdenum slab, comprises the following steps:

[0045] Step 1. Place molybdenum dioxide powder and lanthanum nitrate solution in a double-cone vacuum spray doping mixing dryer, mix for 120 minutes under a vacuum condition of 0.04Mpa, and then dry to obtain lanthanum-doped molybdenum dioxide powder, wherein, The lanthanum content in lanthanum-doped molybdenum dioxide powder is 0.9%, the Fischer particle size of molybdenum dioxide is 5μm, and the bulk density is 1.05g / cm 3 .

[0046] Step 2. The lanthanum-doped molybdenum dioxide powder is subjected to hydrogen reduction and sieving to obtain lanthanum-doped molybdenum powder, wherein the hydrogen reduction temperatures are 850°C, 920°C, 960°C, and 980°C, and the total reduction time is 7 hours; A 200-mesh sieve obtained lanthanum-doped molybdenum powder with an average Fischer particle size of 3.7 μm;

[0047] Step 3. Put the lanthanum-doped molybdenum p...

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Abstract

The invention provides a preparation method of a molybdenum plate blank. The preparation method comprises the following steps that 1, molybdenum dioxide powder and a lanthanum nitrate solution are mixed and dried, and lanthanum-doped molybdenum dioxide powder is obtained, wherein the lanthanum content of the lanthanum-doped molybdenum dioxide powder is (0.75-1.5%); 2, the lanthanum-doped molybdenum dioxide powder is subjected to hydrogen reduction and screened, and lanthanum-doped molybdenum powder is obtained; and 3, the lanthanum-doped molybdenum powder and a proper amount of pure molybdenumpowder are mixed, the lanthanum content is (0.3-1.0)% after mixing, then blank pressing and sintering are conducted, and the lanthanum-doped molybdenum plate blank is obtained. The lanthanum-doped molybdenum plate blank prepared through the method is fine and uniform in grain size and free of coarse grain structures, the surface is bright after the molybdenum plate blank is rolled into a molybdenum sheet, the defects of sand holes, snowflake crystals and the like are avoided, and the surface quality is good; and the lanthanum content of the lanthanum-doped molybdenum powder can be accuratelycontrolled by controlling the concentration and the dosage of the lanthanum nitrate solution, the lanthanum content of the produced lanthanum-doped molybdenum plate blank is accurate and controllable,and the rolling machining performance is stable.

Description

technical field [0001] The invention belongs to the technical field of hard alloy preparation, and in particular relates to a method for preparing a lanthanum-molybdenum slab. Background technique [0002] Molybdenum plates (sheets) are widely used in the production of molybdenum boats, heat shields for high-temperature furnaces, structural parts and heating elements, electric light source parts and vacuum devices. Pure molybdenum slab has the disadvantages of low recrystallization temperature and poor comprehensive mechanical properties. The molybdenum plate (sheet) rolled by pure molybdenum slab has the phenomenon of recrystallization embrittlement, high room temperature brittleness, and high plastic brittle transition temperature, which greatly limit its application. [0003] In order to improve the performance of molybdenum plates (sheets), a certain amount of rare earth elements are usually added to molybdenum slabs, especially after adding rare earth lanthanum, it can...

Claims

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Application Information

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IPC IPC(8): C22C1/04C22C27/04B22F9/22
CPCB22F9/22C22C1/045C22C27/04
Inventor 柳兴光易炼李志翔陈茂静卫茹唐鑫鑫
Owner ZIGONG CEMENTED CARBIDE CORP