CN109894626A - A kind of rotary calcining of Yttrium oxide doping tungsten composite powder and reducing preparation method - Google Patents
A kind of rotary calcining of Yttrium oxide doping tungsten composite powder and reducing preparation method Download PDFInfo
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Abstract
Rotary calcining and reducing preparation method the invention proposes a kind of Yttrium oxide doping tungsten composite powder;The precursor powder that various chemical methods obtain is placed in the revolving speed in rotary furnace and adjusting boiler tube;Then precursor powder is calcined in furnace;Two steps restore and are cooled to room temperature in reducing atmosphere in reducing atmosphere later, finally obtain ultrafine yttria doping tungsten composite powder.The rotary preparation method calcined and restored is suitable for precursor powder made from all chemical methods, while calcining and reduction relative to traditional precursor powder, and the preparation method reduction efficiency of rotary calcining and reduction can improve 10 times or more.The present invention saves resource simultaneously, reduces costs, has saved the time.
Description
Technical field
Rotary calcining and reducing preparation method the invention proposes a kind of Yttrium oxide doping tungsten composite powder, belong to powder
Body prepares field of engineering technology.
Background technique
Tungsten-bast alloy is because numerous excellent performances have a wide range of applications in fields such as high temperature alloy, hard alloy, together
When tungsten be considered as the most possible candidate material of the following fusion reactor PFM.Due to the high-melting-point of tungsten, tungsten-bast alloy is generally by powder
Metallurgy method preparation.But tungsten-bast alloy also has many urgent problems, and sintering densification difficulty, black brittleness, recrystallization are crisp
Change etc..Studies have shown that in refinement crystal grain and in terms of promoting densifying materials, Y2O3It is optimal dispersed oxide phase.
Meanwhile powder is thinner, sintering activity is higher.Currently, preparing the method master of ultrafine yttria doping tungsten composite powder
It to be ball-milling method and chemical method.The powder that ball-milling method obtains can introduce a large amount of impurity, and as Ball-milling Time extends, and refine crystal grain
Effect it is not significant, and it is very serious to reunite.Superfine nano W-Y is obtained at present2O3The method of composite powder is mainly chemistry
Method, including the wet-chemical precipitation method, sol-gal process, spray drying process, Evaporation Precipitation, freeze-drying etc..These methods are all
It is the uniformity doping for having refined precursor powder, and having can achieve atomic level.Moreover, the precursor powder calcining of refinement
It is more abundant with the effect of reduction, be conducive to prepare superfine nano W-Y2O3Composite powder.
However, related scientific research personnel have often only paid attention to refinement precursor powder, and ignore to subsequent calcination and reduction
Process improvement.Subsequent calcination and the process of reduction also also produce important influence to the partial size of powder.It is calcining and is going back
Powdering mode when former is static powdering, generally in one layer of thin powder of tube furnace or batch-type furnace middle berth, wherein tube furnace
Powdering mode is as shown in Figure 1.If the precursor last layer in furnace middle berth is thicker, reducibility gas enters powder bed bottom and does not fill
Point, W-Y can be caused2O3Composite powder crystal grain is seriously grown up.Precursor last layer is relatively thin, although powder reduction is very abundant,
The reduction efficiency of furnace body is lower, and the same time obtains superfine nano W-Y2O3Composite powder is less, wastes vast resources, very
Be not suitable for producing in enormous quantities.The mode of the paving precursor powder of this static state calcine it is especially low with reduction efficiency, be restrict W-Y2O3
One of the key link that nano composite powder is produced in enormous quantities.
Summary of the invention
In view of the deficiencies of the prior art, the invention proposes a kind of Yttrium oxide doping tungsten composite powder it is rotary calcining and
The technology of reducing preparation method.Current status be all be to be calcined and restored after static powdering, low efficiency is at high cost.
Technical solution of the present invention are as follows:
A kind of rotary calcining of Yttrium oxide doping tungsten composite powder and reducing preparation method, comprising the following steps:
(1) precursor powder that various chemical methods obtain is placed in rotary tube furnace and adjusts the revolving speed of boiler tube;
(2) then precursor powder is calcined in furnace;
(3) two steps restore and are cooled to room temperature in reducing atmosphere in reducing atmosphere after, finally obtain ultra-fine oxygen
Change doped yttrium tungsten composite powder.
Boiler tube revolving speed is 3~13 revs/min in the step (1).
Boiler tube inner wall is provided with baffle in the step (1).
In the step (1) chemical method be include the wet-chemical precipitation method, Evaporation Precipitation, spray drying process, collosol and gel
Method, freeze-drying etc..
Calcination atmosphere is air or argon gas in the step (2), and calcination temperature and time are 400~500 DEG C, 0.5~2h.
Reducing atmosphere is hydrogen or carbon monoxide etc. in the step (3), two step reduction temperatures and time is 550~
650 DEG C, 1~2h;700~800 DEG C, 1~2h.
The mode efficiency of static paving precursor powder is extremely low when for current calcining and reduction, waste of resource.This hair
In bright, the rotation speed of the boiler tube by adjusting tube furnace, powder can also follow boiler tube to rotate in calcining and reduction process,
Hydrogen contacts more abundant with precursor powder during this is dynamic, while the boiler tube inner wall of rotary tube furnace has baffle, energy
Powder overturning is helped to also contribute to restoring.Dynamic powdering mode boiler tube schematic cross-section is as shown in Figure 2.It will relative to traditional
The static method of powder tiling tube body, this dynamic rotary calcining and 10 times of the efficiency raising of reduction powder or more.
Advantages of the present invention:
1, it rotatably calcines and the preparation method of reduction is suitable for precursor powder made from all chemical methods, while is opposite
In the calcining and reduction of traditional precursor powder, it is rotary calcine and the preparation method reduction efficiency of reduction can improve 10 times with
On.
2, relative to the calcining and reduction of traditional precursor powder, pass through the preparation method section rotatably calcined and restored
Resource has been saved, for example has reduced the intake of reducibility gas, has reduced costs, has saved the time.
3, the present invention is not only able to achieve superfine nano W-Y2O3The preparation of composite powder, while it is big to be also very suitable for single batch
The superfine nano W-Y of amount2O3The preparation of composite powder.
Detailed description of the invention
Fig. 1: the schematic cross-section of traditional static powdering mode;
Fig. 2: the schematic cross-section of dynamic powdering mode of the present invention;
Fig. 3: the W-Y prepared in embodiment 12O3The XRD diagram piece of composite powder A;
Fig. 4: the W-Y prepared in embodiment 12O3The SEM picture of composite powder A;
Fig. 5: the W-Y prepared in embodiment 12O3The SEM picture of composite powder B;
Fig. 6: the W-Y prepared in embodiment 12O3The SEM picture of composite powder C;
Fig. 7: the W-Y prepared in embodiment 22O3The SEM picture of composite powder A.
Specific embodiment
Feature of the invention is further described below by example, but the invention is not limited to following examples.Using such as
The revolving burner of structure shown in Fig. 2, while using model BTF-1200C-R rotary furnace.Compare for convenience, to control variable,
Error caused by eliminating because of tube furnace model difference.Therefore tube furnace model or BTF- in the comparative test of static powdering
1200C-R rotary furnace, while it is 0 that boiler tube revolving speed, which is arranged, that is, static powdering.
Embodiment 1
(1) by taking single temperature zone rotary furnace BTF-1200C-R as an example, the 30g precursor powder that freeze-drying obtains is placed in
In rotary furnace, and adjusting boiler tube revolving speed is 5 revs/min;
(2) then by precursor powder in argon atmosphere 450 DEG C of calcining 0.5h;
(3) after in pure hydrogen two steps reduction (550 DEG C, 1.5h;750 DEG C, 2h) and be cooled in hydrogen atmosphere
Room temperature finally obtains superfine nano W-1wt%Y2O3Composite powder is labeled as A powder.
(4) compare for convenience, be placed in rotary furnace using 3g freeze-drying precursor powder, and adjust boiler tube revolving speed
For 0 rev/min (i.e. static powdering), subsequent step is identical, is labeled as B powder;30g freeze-drying precursor is used simultaneously
End is placed in rotary furnace, and adjusting boiler tube revolving speed is 0 rev/min (i.e. static powdering), and subsequent step is identical, is labeled as C powder
End.A powder average grain size is 29.4nm, and object phase is as shown in figure 3, surface topography is as shown in Figure 4;B powder average crystal grain ruler
Very little is 28.1nm, and surface topography is as shown in Figure 5;C powder average grain size is 476.1nm, and surface topography is as shown in Figure 6.It is logical
Cross comparison, powder object made from the rotary calcining of discovery Yttrium oxide doping tungsten composite powder and the technology of reducing preparation method
Xiang Chun, crystal grain is small, and the method improves efficiency, saves the time, reduces costs, and has significant advantage.
Embodiment 2
(1) by taking single temperature zone rotary furnace BTF-1200C-R as an example, the 20g precursor powder that Evaporation Precipitation obtains is placed in
In rotary furnace, and adjusting boiler tube revolving speed is 10 revs/min;
(2) then by precursor powder in argon atmosphere 400 DEG C of calcining 2h;
(3) after in pure hydrogen two steps reduction (550 DEG C, 2h;800 DEG C, 1h) and it is cooled in hydrogen atmosphere room
Temperature finally obtains superfine nano W-0.5wt%Y2O3Composite powder is labeled as A powder.
(4) compare for convenience, be placed in rotary furnace using 2g Evaporation Precipitation precursor powder, and adjust boiler tube revolving speed
For 0 rev/min (i.e. static powdering), subsequent step is identical, is labeled as B powder;20g Evaporation Precipitation precursor is used simultaneously
End is placed in rotary furnace, and adjusting boiler tube revolving speed is 0 rev/min (i.e. static powdering), and subsequent step is identical, is labeled as C powder
End.A powder average grain size is 101.4nm, and surface topography is as shown in Figure 7;B powder average grain size is 94.0nm;C powder
Last average grain size is 904.2nm.By comparison, the rotary calcining and reduction of discovery Yttrium oxide doping tungsten composite powder
Powder object made from the technology of preparation method is mutually pure, and crystal grain is small, and the method improves efficiency, saves the time, reduces costs,
With significant advantage.
Embodiment 3
(1) by taking single temperature zone rotary furnace BTF-1200C-R as an example, the 20g precursor powder that sol-gal process obtains is placed in
In rotary furnace, and adjusting boiler tube revolving speed is 3 revs/min;
(2) then by precursor powder in air atmosphere 500 DEG C of calcining 1h;
(3) after in pure hydrogen two steps reduction (650 DEG C, 1h;700 DEG C, 2h) and it is cooled in hydrogen atmosphere room
Temperature finally obtains superfine nano W-1wt%Y2O3Composite powder is labeled as A powder.
(4) compare for convenience, be placed in rotary furnace using 2g sol-gal process precursor powder, and adjust boiler tube revolving speed
For 0 rev/min (i.e. static powdering), subsequent step is identical, is labeled as B powder;It is set using 20g sol-gal process precursor powder
In rotary furnace, and adjusting boiler tube revolving speed is 0 rev/min (i.e. static powdering), and subsequent step is identical, is labeled as C powder.A
Powder average grain size is 62.9nm;B powder average grain size is 57.2nm;C powder average grain size is
360.2nm.By comparison, the technology system of the rotary calcining and reducing preparation method of discovery Yttrium oxide doping tungsten composite powder
The powder object obtained is mutually pure, and crystal grain is small, and the method improves efficiency, saves the time, reduces costs, and has significant advantage.
Embodiment 4
(1) by taking single temperature zone rotary furnace BTF-1200C-R as an example, the 30g precursor powder that spray drying process obtains is placed in
In rotary furnace, and adjusting boiler tube revolving speed is 5 revs/min;
(2) then by precursor powder in argon atmosphere 500 DEG C of calcining 1h;
(3) after in pure hydrogen two steps reduction (600 DEG C, 1.5h;750 DEG C, 1.5h) and it is cold in hydrogen atmosphere
To room temperature, superfine nano W-2wt%Y is finally obtained2O3Composite powder is labeled as A powder.
(4) compare for convenience, be placed in rotary furnace using 3g spray drying process precursor powder, and adjust boiler tube revolving speed
For 0 rev/min (i.e. static powdering), subsequent step is identical, is labeled as B powder;30g spray drying process precursor is used simultaneously
End is placed in rotary furnace, and adjusting boiler tube revolving speed is 0 rev/min (i.e. static powdering), and subsequent step is identical, is labeled as C powder
End.A powder average grain size is 62.9nm;B powder average grain size is 54.1nm;C powder average grain size is
641.2nm.By comparison, the technology system of the rotary calcining and reducing preparation method of discovery Yttrium oxide doping tungsten composite powder
The powder object obtained is mutually pure, and crystal grain is small, and the method improves efficiency, saves the time, reduces costs, and has significant advantage.
Embodiment 5
(1) by taking single temperature zone rotary furnace BTF-1200C-R as an example, the 20g precursor powder that the wet-chemical precipitation method obtain is set
In rotary furnace, and adjusting boiler tube revolving speed is 10 revs/min;
(2) then by precursor powder in air atmosphere 500 DEG C of calcining 1h;
(3) after in pure carbon monoxide two steps reduction (550 DEG C, 1.5h;750 DEG C, 2h) and in carbon monoxide gas
It is cooled to room temperature in atmosphere, finally obtains superfine nano W-0.2wt%Y2O3Composite powder is labeled as A powder.
(4) compare for convenience, be placed in rotary furnace using 3g wet-chemical precipitation method precursor powder, and adjust boiler tube and turn
Speed is 0 rev/min (i.e. static powdering), and subsequent step is identical, is labeled as B powder;30g wet-chemical precipitation method forerunner is used simultaneously
Body powder is placed in rotary furnace, and adjusting boiler tube revolving speed is 0 rev/min (i.e. static powdering), and subsequent step is identical, is labeled as
C powder.A powder average grain size is 57.5nm;B powder average grain size is 49.0nm;C powder average grain size is
425.7nm.By comparison, the technology system of the rotary calcining and reducing preparation method of discovery Yttrium oxide doping tungsten composite powder
The powder object obtained is mutually pure, and crystal grain is small, and the method improves efficiency, saves the time, reduces costs, and has significant advantage.
A kind of rotary calcining for Yttrium oxide doping tungsten composite powder that the present invention is disclosed and proposed and reducing preparation method,
Those skilled in the art can be by using for reference present disclosure, and the appropriate links such as condition route that change are realized, although method of the invention
Be described by preferred embodiment with technology of preparing, related technical personnel obviously can not depart from the content of present invention,
Methods and techniques described herein route is modified or is reconfigured in spirit and scope, to realize final preparation skill
Art.In particular, it should be pointed out that all similar replacements and change are apparent to those skilled in the art, he
Be considered as being included in spirit of that invention, range and content.
Claims (6)
1. a kind of Yttrium oxide doping tungsten composite powder it is rotary calcining and reducing preparation method, feature the following steps are included:
(1) precursor powder that various chemical methods obtain is placed in rotary tube furnace and adjusts the revolving speed of boiler tube;
(2) it is then calcined in rotary furnace;
(3) last two steps in reducing atmosphere restore and are cooled to room temperature in reducing atmosphere, obtain ultrafine yttria doping
Tungsten composite powder.
2. the method as described in claim 1, it is characterized in that boiler tube revolving speed is 3~13 revs/min in the step (1).
3. the method as described in claim 1, it is characterized in that boiler tube inner wall is provided with baffle in the step (1).
4. the method as described in claim 1, it is characterized in that in the step (1) chemical method be include the wet-chemical precipitation method, steam
Send out the precipitation method, spray drying process, sol-gal process or freeze-drying.
5. the method as described in claim 1, it is characterized in that calcination atmosphere is air or argon gas, calcining temperature in the step (2)
Degree is 400~500 DEG C, and calcination time is 0.5~2h.
6. the method as described in claim 1, it is characterized in that reducing atmosphere is hydrogen or carbon monoxide in the step (3),
Two step reduction temperatures and time are 550~650 DEG C, 1~2h;700~800 DEG C, 1~2h.
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Application publication date: 20190618 |