CN105702542A - Rhenium doped tungsten-based alloy cathode and preparation method thereof - Google Patents
Rhenium doped tungsten-based alloy cathode and preparation method thereof Download PDFInfo
- Publication number
- CN105702542A CN105702542A CN201510760269.4A CN201510760269A CN105702542A CN 105702542 A CN105702542 A CN 105702542A CN 201510760269 A CN201510760269 A CN 201510760269A CN 105702542 A CN105702542 A CN 105702542A
- Authority
- CN
- China
- Prior art keywords
- tungsten
- rhenium
- cathode
- based alloy
- preparation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
The invention provides a preparation method of a rhenium doped tungsten-based alloy cathode. The preparation method comprises the steps of: mixing metal tungsten powder with rhenium powder to obtain evenly mixed tungsten-rhenium alloy powder; mixing the tungsten-rhenium alloy powder with 1.5wt% nitro-cotton solution evenly, applying the mixed solution to the surface of a tungsten cathode substrate, and baking; and placing a tungsten wire with the tungsten-rhenium alloy powder applied on surface into a high-temperature hydrogen furnace, and keeping the tungsten wire at the temperature of 1600+/-50 DEG C for 10-15 minutes, thereby preparing the rhenium doped tungsten-based alloy cathode. The invention further provides the rhenium doped tungsten-based alloy cathode prepared by adopting the method. The rhenium doped tungsten-based alloy cathode provided by the invention can increase emission current density of a pure tungsten cathode used for a high-power continuous wave magnetron, reduce working temperature of the pure tungsten cathode, reducing surface evaporation rate of the cathode, and further prolonging service life of the cathode.
Description
Technical field
The invention belongs to electric vacuum technology field, relate more specifically to a kind of doped tungsten-based alloy cathode of rhenium and preparation method thereof, the doped tungsten-based alloy cathode of this rhenium adopts the doped tungsten-based alloy of 5wt% rhenium metal to make, compared to pure tungsten wire cathode, the emission of negative electrode can be improved, reduce the operating temperature of negative electrode, extend the life-span of negative electrode。
Background technology
Along with magnetron develops towards high-output power direction, ordinary oxide negative electrode, barium-tungsten dispense cathode etc. are because it is weak to anode high voltage, weak to electronics, ion bom bardment, it is easy to occur the shortcomings such as electric spark to be little to application。Therefore, in middle power (less than 3KW) magnetron, all adopt the thoriated tungsten cathode of carbonization。And in high-power (more than 10KW) continuous wave magnetron of high anode voltage (more than 10kV), it is generally adopted directly-heated type pure tungsten (W) wire cathode that emissive power is only small, it is good that pure W wire cathode has launch stability compared to ordinary oxide negative electrode and barium-tungsten dispense cathode, resistance to electronics, ion bom bardment ability are strong, the advantages such as anti-toxic is strong。But, high power CW ripple magnetron is under ensureing normal output power situation, and its negative electrode is generally operational between 2450-2700K temperature, and too high negative electrode operating temperature causes that cathode surface evaporation is too fast, when negative electrode diameter lower than initial diameter 90% time, namely declaration cathode life end。Therefore in continuous wave magnetron, the termination in pure W wire cathode life-span is the one of the main reasons causing magnetron life to terminate。
Summary of the invention
In view of this, it is an object of the invention to provide a kind of high power CW ripple doped tungsten-based alloy cathode of magnetron rhenium and preparation method thereof, to improve the emission of pure tungsten wire cathode, reduce the operating temperature of negative electrode, extend the service life of negative electrode。
To achieve these goals, the preparation method that the invention provides the doped tungsten-based alloy cathode of a kind of rhenium, comprise the following steps:
A, metal tungsten powder and rhenium powder are mixed, the tungsten-rhenium alloy powder being uniformly mixed；
B, by described tungsten-rhenium alloy powder and 1.5wt% cotton solution Homogeneous phase mixing, mixed solution is put on tungsten cathode substrate surface, baking；
C, surface is applied with tungsten-rhenium alloy powder after tungsten filament put in high temperature hydrogen furnace, at 1600 ± 50 DEG C be incubated 10～15 minutes, namely prepare the doped tungsten-based alloy cathode of described rhenium。
Wherein, tungsten powder in described a step and rhenium powder are purity is 99.9%, and mean diameter is 1～3 μm。
And, by the doped tungsten-based alloy cathode of rhenium that above-mentioned preparation method prepares。
By experimental results demonstrate, the fusing point of rhenium metal is close to pure tungsten, the launch stability that the doped tungsten-based alloy cathode of 5wt%Re not only remains pure tungsten wire cathode is good, resistance to electronics, ion bom bardment ability are strong, the advantages such as anti-poisoning performance is strong, but also there is bigger heat emission electric current density and secondary electron yield。Thus, the doped tungsten-based alloy cathode of 5wt% rhenium of the present invention can provide identical heat emission electric current density when lower than pure tungsten wire cathode temperature at least 400 DEG C, meanwhile, the secondary electron yield of this alloy cathode is than the pure tungsten wire cathode big 80% of preparation under the same terms。In sum, the doped tungsten-based alloy cathode of 5wt% rhenium of the present invention can improve the emission of high power CW ripple magnetron pure tungsten wire cathode, reduces the operating temperature of pure tungsten wire cathode, reduces cathode surface evaporation rate, thus extending the life-span of negative electrode。
Accompanying drawing explanation
Fig. 1 is the preparation flow figure of existing common pure tungsten wire cathode；
Fig. 2 is the preparation flow figure of the doped tungsten-based alloy cathode of rhenium of the present invention；
Fig. 3 is the structural representation of the doped tungsten-based alloy cathode of rhenium of the present invention；
Fig. 4 is the surface power spectrum EDS figure of the doped tungsten-based alloy cathode of rhenium of the present invention；
Fig. 5 is the rhenium doped tungsten-based alloy cathode heat emission electric current density correlation curve schematic diagram with pure tungsten wire cathode of the present invention；
Fig. 6 is the secondary electron yield curve synoptic diagram of the doped tungsten-based alloy cathode of rhenium of the present invention；
Fig. 7 is the life curve schematic diagram of the doped tungsten-based alloy cathode of rhenium of the present invention。
Detailed description of the invention
For making the object, technical solutions and advantages of the present invention clearly understand, below in conjunction with specific embodiment, and with reference to accompanying drawing, the present invention is described in further detail。
The invention discloses a kind of doped tungsten-based alloy cathode of rhenium, this alloy cathode adopts the tungsten-rhenium alloy of 5wt% rhenium doping as electronic emission material, sprays this electronic emission material to put into sinter in high temperature hydrogen stove after pure tungsten wire cathode substrate surface and namely prepares。The doped tungsten-based alloy cathode of this rhenium may be used for high power CW ripple magnetron, and the life-span on life-span platform alreadys more than 2000 hours at present。
The preparation method that the invention also discloses the doped tungsten-based alloy cathode of a kind of rhenium, comprises the following steps:
A, metal W powder and Re powder are mixed after grind and within 24 hours, obtain mixed uniformly tungsten-rhenium alloy powder；
B, by after mixed uniformly tungsten-rhenium alloy powder and 1.5wt% cotton solution Homogeneous phase mixing, utilize spray gun that mixed solution and sprayed overlays on W silk substrate surface, then, baking W silk surface is evaporated completely to moisture；
C, surface is sprayed upper tungsten-rhenium alloy powder after W silk put in high temperature hydrogen furnace insulation at 1600 ± 50 DEG C and be namely prepared into this alloy cathode in 10～15 minutes。
Wherein, the purity of metal W powder and Re powder is preferably 99.9%, and mean diameter is preferably 1～3 μm。Wherein, the W powder in a step and Re powder are to mix according to percetage by weight 95%: 5%。
Wherein, the grinding in a step, is carry out in Achates alms bowl, mixed grinding≤24 hour。
Wherein, the tungsten-rhenium alloy powder in b step and 1.5wt% cotton solution are mix at 1: 3 by weight, incorporation time≤1 hour。
Wherein, the baking in b step is to carry out under infrared lamp, baking time >=2 hour。
Wherein, the sintering process in step c is: first heat up, and within 0.5～1 hour consuming time, linearly rises to 1600 ± 50 DEG C from room temperature, and after being incubated 10～15 minutes, cooling, during cooling, is linearly down to room temperature in 2～4 hours consuming time from 1600 ± 50 DEG C。
Wherein, in step c, the tungsten-rhenium alloy layer thickness of tungsten filament sintering is between 50～200 μm。
The preparation method flow chart of the doped tungsten-based alloy cathode of rhenium of the present invention is as in figure 2 it is shown, the preparation method of tungsten-bast alloy negative electrode relative to prior art as shown in Figure 1, and in figure, black matrix is the inventive point of the present invention。
As a preferred embodiment, the preparation method of the doped tungsten-based alloy cathode of rhenium of the present invention comprises the following steps: choose purity to be 99.9wt% particle mean size be the metal W powder of 1～3 μm and Re powder is pour Achates alms bowl ground and mixed 24 hour until uniformly at 95%: 5% by weight percentage。Then by the W-Re metal alloy powder of mix homogeneously and 1.5wt% cotton solution according to percentage by weight be 1: 3 pour into Achates alms bowl mixes 1 hour after pour into and spray gun uniformly spray at W silk substrate surface, then the tungsten filament processed is put into and toasts more than 2 hours under infrared lamp until moisture evaporates completely。Metal W silk after finally surface spraying upper tungsten-rhenium alloy bisque is put into and is incubated the preparation namely completing the doped tungsten-based alloy cathode of this rhenium for 10～15 minutes in high temperature hydrogen furnace at 1600 ± 50 DEG C。The structure of the alloy cathode of the present invention prepared is as shown in Figure 3。
The alloy cathode performance of the present invention prepared is detected。Doped tungsten-based for 5wt% rhenium alloy cathode silk is loaded in cylindrical shape anode vacuum diode。Vacuum diode system is incubated after degassing in 1～1.5 hour at 500 DEG C, then with 50～60mA high frequency electric degassing 5～10 minutes, 80～120mA high frequency electric degassing 2～5 minutes, now system vacuum was better than 10-5Pa。Hereafter carry out heat emission characteristic test then through after negative electrode high temperature degassing, activation and seasoned 10 hours, test adopts optical pyrometer cathode temperature is measured。Test result is as shown in Figure 5。
Cathode life test is carried out by carrying out the vacuum diode insertion life-span platform equipped with this alloy cathode silk after heat emission characteristic is completed。Its test result is as shown in Figure 6。
Fig. 4 show the energy spectrum analysis EDS figure of tungsten-rhenium alloy layer in this alloy cathode, from Fig. 4 it is known that energy disperse spectroscopy is measured finds that the tungsten-rhenium alloy layer Main Ingredients and Appearance of the present invention has metal W and Re, and their percentage by weight respectively 90.55% and 5.3%, the closely ratio of original formulation。Additionally, EDS analyser finds the C having 4.15% content, then it is likely due to the C that guncotton decomposites during high temperature in hydrogen furnace and the CO in absorption air2Cause etc. reason。
Show the heat emission characteristic curve chart of this alloy cathode from Fig. 5, as can be seen from Figure 5 this alloy cathode is zero-field emission electric current density respectively 0.13A/cm when 1700 DEG C, 1800 DEG C, 1900 DEG C in cathode temperature2、0.40A/cm2、1.1/cm2, and the zero-field emission electric current density of pure W wire cathode reaches 0.11A/cm2、0.28A/cm2、0.70A/cm2Time temperature respectively 2100 DEG C, 2200 DEG C, 2300 DEG C。The doped tungsten-based alloy cathode of rhenium is compared to pure W wire cathode, it is possible to make operating temperature at least reduce by more than 400 DEG C, it is shown that this alloy cathode has powerful heat emission ability。In addition, the work function calculating this alloy cathode according to null field heat emission electron current density equation (Li Chasen-Dao Schumann formula) is 3.6eV, and the work function of the pure W wire cathode prepared under the same conditions is 4.5eV, by contrast, it is possible to the work function of pure W wire cathode is reduced by 20%。
Fig. 6 show the secondary electron yield curve synoptic diagram of the tungsten-bast alloy negative electrode of different proportion metal Re doping, in Fig. 6, metal Re doping ratio is 20%, 10%, 6%, 5%, 4%, 3%, it is expressed as R5, R4, R2, R1, R3, R6, by pure tungsten powder sintered cathode secondary emissionratio as a comparison, it is expressed as R7。It is known that only when Re doping ratio is when being 5%, the doped tungsten-based alloy cathode of rhenium has maximum secondary electron yield, and its value is 1.8 from figure。And now pure tungsten powder sintered cathode maximum secondary electron emission coefficiency value is only about 1.0, by contrast, it is possible to the secondary electron yield of the pure W negative electrode prepared under the same terms is improved 80%。
It is 1800 DEG C that Fig. 7 show the doped tungsten-based alloy cathode of this rhenium in brightness temperature, initial transmissions electric current density 0.4A/cm2Time life curve。As can be seen from Figure 7 this alloy cathode life-span under these conditions alreadys more than 2000 hours, and during at present cathode life remains in and proceeds, it is known that when, after this alloy cathode 2000 hours life, it is drawn electric current density and is still not less than 0.4A/cm from Fig. 72。Additionally, in the life span of negative electrode, it does not have monitor this alloy cathode and phenomenons such as evapotranspiring occurs, illustrate that this alloy cathode has higher job stability。
Table 1 is that the doped tungsten-based alloy cathode of rhenium of the present invention is applied in 15kW continuous wave magnetron real work situation。It is known that the application of this alloy cathode can make the pure pre-thermocurrent of W cathode filament can reduce 2A from table 1, operating current can reduce 1A, this all can make magnetron reduce the operating temperature of pure W wire cathode while ensureing normal output power, thus extending negative electrode working life in pipe。
Table 1
Particular embodiments described above; the purpose of the present invention, technical scheme and beneficial effect have been further described; it it should be understood that; the foregoing is only specific embodiments of the invention; it is not limited to the present invention; all within the spirit and principles in the present invention, any amendment of making, equivalent replacement, improvement etc., should be included within protection scope of the present invention。
Claims (10)
1. the preparation method of the doped tungsten-based alloy cathode of rhenium, it is characterised in that comprise the steps:
A, metal tungsten powder and rhenium powder are mixed, the tungsten-rhenium alloy powder being uniformly mixed；
B, by described tungsten-rhenium alloy powder and 1.5wt% cotton solution Homogeneous phase mixing, mixed solution is put on tungsten cathode substrate surface, baking；
C, surface is applied with tungsten-rhenium alloy powder after tungsten filament put in high temperature hydrogen furnace, at 1600 ± 50 DEG C be incubated 10～15 minutes, namely prepare the doped tungsten-based alloy cathode of described rhenium。
2. the preparation method of the doped tungsten-based alloy cathode of rhenium as claimed in claim 1, it is characterised in that tungsten powder in described a step and rhenium powder are purity is 99.9%, and mean diameter is 1～3 μm。
3. the preparation method of the doped tungsten-based alloy cathode of rhenium as claimed in claim 1, it is characterised in that tungsten powder and rhenium powder in described a step are 95%: 5% mixing according to percetage by weight。
4. the preparation method of the doped tungsten-based alloy cathode of rhenium as claimed in claim 1, it is characterised in that the grinding in described a step, is carry out in Achates alms bowl, mixed grinding≤24 hour。
5. the preparation method of the doped tungsten-based alloy cathode of rhenium as claimed in claim 1, it is characterised in that the tungsten-rhenium alloy powder in described b step and 1.5wt% cotton solution are to be 1 by weight∶3 mixing, incorporation time≤1 hour。
6. the preparation method of the doped tungsten-based alloy cathode of rhenium as claimed in claim 1, it is characterised in that the baking in described b step is to carry out under infrared lamp, baking time >=2 hour。
7. the preparation method of the doped tungsten-based alloy cathode of rhenium as claimed in claim 1, it is characterized in that, sintering process in described step c is: first heat up, within 0.5～1 hour consuming time, linearly rise to 1600 ± 50 DEG C from room temperature, cooling after being incubated 10～15 minutes, during cooling, within 2～4 hours consuming time, linearly it is down to room temperature from 1600 ± 50 DEG C。
8. the preparation method of the doped tungsten-based alloy cathode of rhenium as claimed in claim 1, it is characterised in that in described step c, the thickness of the tungsten-rhenium alloy layer of tungsten filament sintering is between 50～200 μm。
9. the preparation method of the doped tungsten-based alloy cathode of rhenium as claimed in claim 1, it is characterised in that the doped tungsten-based alloy cathode of described rhenium of preparation is used for high power CW ripple magnetron。
10. the doped tungsten-based alloy cathode of rhenium prepared by the preparation method of the doped tungsten-based alloy cathode of the rhenium as described in claim 1 to 9 any one。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510760269.4A CN105702542A (en) | 2015-11-09 | 2015-11-09 | Rhenium doped tungsten-based alloy cathode and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510760269.4A CN105702542A (en) | 2015-11-09 | 2015-11-09 | Rhenium doped tungsten-based alloy cathode and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105702542A true CN105702542A (en) | 2016-06-22 |
Family
ID=56227867
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510760269.4A Pending CN105702542A (en) | 2015-11-09 | 2015-11-09 | Rhenium doped tungsten-based alloy cathode and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105702542A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109037007A (en) * | 2018-07-03 | 2018-12-18 | 九江学院 | A kind of preparation method of the directly-heated type cathode of resistance to electron bombardment |
| CN109065422A (en) * | 2018-07-03 | 2018-12-21 | 九江学院 | A kind of preparation method of directly-heated type carbonization tungsten-rhenium alloy cathode |
| CN109065424A (en) * | 2018-07-03 | 2018-12-21 | 九江学院 | A kind of preparation method of rhenium dipping scandium tungsten-bast alloy cathode |
| CN110112045A (en) * | 2019-04-01 | 2019-08-09 | 九江学院 | High power magnetic keyholed back plate direct-heated cathode and preparation method thereof |
| CN113053704A (en) * | 2021-03-18 | 2021-06-29 | 中国科学院空天信息创新研究院 | Photocathode and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04259726A (en) * | 1991-02-13 | 1992-09-16 | Nec Corp | Impregnated-type cathode |
| CN1801427A (en) * | 2004-12-30 | 2006-07-12 | 中国科学院电子学研究所 | Method for preparing metal nanometer thin film dipped barium-tungsten cathode |
-
2015
- 2015-11-09 CN CN201510760269.4A patent/CN105702542A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04259726A (en) * | 1991-02-13 | 1992-09-16 | Nec Corp | Impregnated-type cathode |
| CN1801427A (en) * | 2004-12-30 | 2006-07-12 | 中国科学院电子学研究所 | Method for preparing metal nanometer thin film dipped barium-tungsten cathode |
Non-Patent Citations (1)
| Title |
|---|
| 漆世锴等: "一种连续波磁控管用铼掺杂钨基合金阴极研究", 《微波学报》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109037007A (en) * | 2018-07-03 | 2018-12-18 | 九江学院 | A kind of preparation method of the directly-heated type cathode of resistance to electron bombardment |
| CN109065422A (en) * | 2018-07-03 | 2018-12-21 | 九江学院 | A kind of preparation method of directly-heated type carbonization tungsten-rhenium alloy cathode |
| CN109065424A (en) * | 2018-07-03 | 2018-12-21 | 九江学院 | A kind of preparation method of rhenium dipping scandium tungsten-bast alloy cathode |
| CN110112045A (en) * | 2019-04-01 | 2019-08-09 | 九江学院 | High power magnetic keyholed back plate direct-heated cathode and preparation method thereof |
| CN113053704A (en) * | 2021-03-18 | 2021-06-29 | 中国科学院空天信息创新研究院 | Photocathode and preparation method thereof |
| CN113053704B (en) * | 2021-03-18 | 2024-03-19 | 中国科学院空天信息创新研究院 | Photocathode and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105702542A (en) | Rhenium doped tungsten-based alloy cathode and preparation method thereof | |
| US2491284A (en) | Electrode for electron discharge devices and method of making the same | |
| Gaertner et al. | Modern Developments in Vacuum Electron Sources | |
| CN109037007B (en) | Preparation method of directly-heated electron bombardment resistant cathode | |
| CN105304436B (en) | Directly heated cathode and preparation method thereof | |
| CN109065424B (en) | Preparation method of rhenium-impregnated scandium-tungsten-based alloy cathode | |
| CN109065422B (en) | Preparation method of directly-heated high-temperature tungsten-rhenium alloy cathode | |
| CN109390571A (en) | A kind of lithium ion battery silicon-carbon cathode material and preparation method | |
| Yang et al. | Studies on the pressed yttrium oxide-tungsten matrix as a possible dispenser cathode material | |
| CN105788996B (en) | A kind of submicron film scandium tungsten cathode and preparation method thereof | |
| CN105645946B (en) | A kind of dipping dispenser cathode aluminate containing scandium and preparation method thereof | |
| CN101834106B (en) | Tungsten-based impregnated cathode and preparation method thereof | |
| JP4648527B2 (en) | Method for manufacturing cathode | |
| CN107068517A (en) | A kind of magnetron matches somebody with somebody the production method for applying mechanically cold cathode and cold cathode head | |
| CN109378266A (en) | A kind of environment-friendly type cathode material and preparation method thereof | |
| Wang et al. | preparation and evaluation of the ammonium perrhenate impregnated Ni sponge Oxide Cathode | |
| CN106229246B (en) | Cold cathode electron gun of vacuum electron magnetron | |
| US1552310A (en) | Electrode for discharge tubes | |
| Wang et al. | Progress on RE 2 O 3-Mo/W matrix secondary emitter materials | |
| CN105810531A (en) | Preparation method of scandia-doped dispenser cathode material with turned surface | |
| US3099763A (en) | Cathode ray tube with silica coated phosphor screen | |
| Li et al. | Application of hydrogen vacuum treatment of palladium powders for production of efficient metal alloy cathodes of self-heated magnetron | |
| CN110676137B (en) | Preparation method of cathode for magnetron | |
| Fu et al. | Spherical field emission cathode based on carbon nanotube paste and its application in luminescent bulbs | |
| WO2018036068A1 (en) | Carbonized la2o3 and lu2o3 co-doped mo cathode material and preparation method therefor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20160622 |
|
| WD01 | Invention patent application deemed withdrawn after publication |