Method for producing potassium-contd. metal tungsten bars

A production method and metal tungsten technology, applied in the field of production of potassium-containing metal tungsten bars, can solve the problems of low pressing and pre-sintering yield, affect the quality of potassium-containing tungsten bars, reduce product performance, etc., and achieve service life and anti-sagging Improved performance, high compact strength and high yield, and reduced damage and scrap rates

Active Publication Date: 2006-04-12
ZIGONG CEMENTED CARBIDE CORP
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AI Technical Summary

Problems solved by technology

While the above background technology retains a sufficient amount of potassium elements in pickling, a considerable part of harmful elements such as silicon and aluminum are also retained. A large number of voids, resulting in uneven crystallization and low density (less than 17.6g / cm2) 3 ) and other defects
These defects seriously affect the quality of potassium-containing tungsten rods and reduce the performance of subsequent products. Therefore, there are disadvantages such as product cross-section crystallization and uneven distribution of potassium elements, low product density, poor performance of subsequent processing and subsequent products; in addition, pressed billets The control pressure is only 20-28MPa, the billet strength is still very low, it is easy to cause fracture and damage during the operation and pre-sintering process, and there are still disadvantages of low yield of pressing and pre-sintering

Method used

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Examples

Experimental program
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Effect test

specific Embodiment approach 2

[0023] Still take the production of φ15×300mm potassium metal tungsten bar 1000kg as an example:

[0024] A. Preparation of doped blue tungsten powder: high-purity blue tungsten powder 1500kg, H 2 SiO 3 : 6800g, KOH: 5500g, Al(NO 3 ) 3 9H 2 O: 3500g, the preparation process is the same as Embodiment 1;

[0025] Reduction treatment, pickling, green compact, pre-sintering and vertical melting sintering, process B, C, D, E and F and recipe

[0026] 3 and 1, after acid washing: doped tungsten powder with Fibonacci particle size of 3.8 μm, potassium content of 75 ppm, and oxygen content of 600 ppm; after vertical melting and sintering: oxygen content of less than 40 ppm, potassium content of 51 ppm, and density of more than 17.3 g / cm 3 tungsten bars;

[0027] G. Intermediate frequency sintering: sinter in a hydrogen atmosphere at 2200°C for 4 hours, and the product obtained after cooling has an oxygen content of 15ppm, a potassium content of 51p...

specific Embodiment approach 3

[0028] This method takes the production of 1000kg potassium metal tungsten bar of φ18×400mm as an example:

[0029] A. Preparation of doped blue tungsten powder: high-purity blue tungsten powder 1500kg, H 2 SiO 3 : 6960g, KOH: 5800g, Al(ON 3 ) 3 4500g, the preparation method is the same as method 1;

[0030] B. Reduction treatment: This method adopts two reductions, both of which are carried out in an eleven-tube five-belt reduction furnace and under a hydrogen atmosphere. The first reduction temperature is 500-650 ° C, and the treatment is 6.0 hours. After cooling, pass through a 120-mesh sieve; The second-stage reduction temperature is 630-940°C, the treatment time is 5 hours, and passed through a 160-mesh sieve after cooling;

[0031] C, pickling: hydrochloric acid and hydrofluoric acid pickling time are 40 minutes; All the other are the same as mode 1, get Fischer particle size 3.90 μ m, potassium content 95ppm, oxygen content is 700ppm doped tungsten powder;

[0032]...

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Abstract

A technology for manufacturing the K-contained tungsten strips by powder metallurgy includes such steps as preparing K doped tungsten powder, reducing one or two times, acid washing, die pressing, pre-sintering, vertical smelting and indirect sintering. Its advantages are high strength, purity and rate of qualified products, and high uniformity of crystal grains and K element.

Description

technical field [0001] The invention belongs to a method for producing raw materials for high-temperature heating, luminous bodies and high-temperature-resistant components in the field of powder metallurgy, in particular a method for producing potassium-containing tungsten strips by adopting a doping method. Background technique [0002] Potassium-containing metal tungsten bars are raw materials for the manufacture of electric light source materials, high-temperature heating elements, and high-temperature-resistant components. The traditional production method is to first add elements such as silicon, aluminum, and potassium to tungsten oxide (including blue tungsten) powder, and then The tungsten oxide powder mixed with these elements is reduced and washed with hydrochloric acid and hydrofluoric acid to obtain doped tungsten powder. The doped tungsten powder is then pressed into billets and then vertically sintered to obtain potassium-containing metal tungsten bars (also kn...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F3/10B22F9/22
Inventor 缪兵周伟刘立新李伟勤
Owner ZIGONG CEMENTED CARBIDE CORP
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