Micro-Doped Lanthanum Tungsten Preparation

A micro- lanthanum -doped tungsten preparation method comprises the following steps :

( 1 ) The paratungstate in high purity hydrogen reduction furnace in pre- reduced blue tungsten ;

( 2 ) Wet incorporation of potassium silicate , aluminum nitrate solution , dried by stirring the mixture , the potassium, silicon, aluminum, tungsten adsorbed in the gap to obtain a doped tungsten blue ;

( 3 ) The use of pressure guns lanthanum acid ammonia solution in spray form to place the doped tungsten blue spray doping pot while stirring , until after spray drying, to obtain amino acid lanthanum doped tungsten blue ; < br />
( 4 ) The blue tungsten doped lanthanum acid into ammonia reduction furnace in high purity hydrogen reduction reaction to obtain a reduction of lanthanum tungsten alloy coarse powder ;

( 5) Reducing the tungsten alloy powder of lanthanum quantitative hydrochloric acid, hydrofluoric acid washing to remove the excess dopant and other impurities to obtain lanthanum tungsten alloy powder ;

( 6 ) Using isostatic press kit to install the elastic modulus of lanthanum tungsten alloy powder is applied to the equal force , made ​​of uniform density tungsten billet ;

( 7 ) Hydrogen tungsten billet under the protection of pre- sintered to obtain a pre-sintered article ;

( 8 ) Pre-sintered in hydrogen under the protection of vertical melt sintering , melting sintering get vertical bar ;

( 9 ) Using the swaging equipment carried on the vertical melt sintering of forging, sintering of the vertical melt gradually reduced cross-section , the length increases, billet within the organizational structure of the tungsten grains and surface condition changes state to prepare tungsten rod ; < br />
( 10 ) Annealing the tungsten rod ; ( 11 ) the annealed then swaging tungsten rod having a diameter of 3.7mm tungsten rod ;

( 12 )On the turntable for coarse tungsten rod tension , tungsten rod through the die holes turntable after the cross section is reduced, increase in length , to obtain a crude tungsten wire ;

( 13 ) The crude tungsten in air by flame oxidation anneal , and after the coating of graphite and a small compression ratio, single stretch, eliminate work hardening and reduce the tensile strength filament ;

( 14) The crude tungsten single stretched via a plurality of the desired motif is drawn into thin tungsten wire. Moreover , in step ( 7 ) in the pre-sintering temperature of 1200 ~ 1400 ° C, sintering time 30 to 50 minutes.

Moreover , in step ( 3 ) in the vertical melt temperature of the final sintering sink 50 ~ ^ 50 ° C, the sintering time is 60 to 70 minutes to obtain the vertical melt density of sintered article 17. 2 ~ 17. 6g/cm3.


Tungsten Alloy Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-alloy.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com;sales@xiamentungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

 

• < Prev
• Next >