CN105244244B

CN105244244B - Oxide cathode

Info

Publication number: CN105244244B
Application number: CN201510668734.1A
Authority: CN
Inventors: 何擎
Original assignee: GANSU HONGGUANG ELECTRICAL Co Ltd
Current assignee: GANSU HONGGUANG ELECTRICAL Co Ltd
Priority date: 2015-10-13
Filing date: 2015-10-13
Publication date: 2017-04-26
Anticipated expiration: 2035-10-13
Also published as: CN105244244A

Abstract

The invention provides an oxide cathode, which particularly comprises the following steps: preparing a cathode-based metal, and reserving a geometric margin on the peripheral surface of an emission layer; pouring nickel powder onto the cathode-based metal by a molding method and putting the entire cathode-based metal together with a mold into a hydrogen furnace for sintering into a nickel sponge layer, reserving a certain geometric margin on the prepared nickel sponge layer, filling the nickel sponge layer with alkali earth metal carbonate, mechanically compacting an emission surface of a cathode emission layer, and removing the residual geometric margin; carrying out pre-decomposition on the oxide cathode before pipe filling; and clamping the oxide cathode on a chuck of a lathe, turning the emission layer and the peripheral surface, removing the residual geometric margin, and then wiping away all particles attached to the cathode surface. The cathode surface provided by the invention becomes smooth, regular, bright and clean; a hot particle emission angle is reduced; deformation of emission electron density distribution is limited; the particle bombardment resistance of the cathode is improved; the sparking probability of the cathode emission surface is reduced; the work stability of the cathode is improved; and the lifetime of the cathode is prolonged.

Description

A kind of oxide-coated cathode

Technical field

The present invention relates to electric original paper, and in particular to a kind of oxide-coated cathode.

Background technology

The extensive way of oxide-coated cathode manufacture is in Base Metal using mechanography（Nickel or tungsten）On prepare metal sponge layer, Fill alkaline earth metal carbonate in spongy layer again（Binary salt brium carbonate, strontium carbonate；Ternary salt brium carbonate, strontium carbonate, carbonic acid Calcium；Quaternary salt brium carbonate, strontium carbonate, calcium carbonate, scandium oxide）Emission layer is made, using front predecomposition.Oxide-coated cathode emission layer The flatness on surface, roughness, cleanliness factor, directly affect size of current, stability, Density Distribution and the negative electrode of launching electronics Life-span.In order to improve the physical state of transmitting layer surface, disclosed way has two kinds：A kind of way is to be divided into emission layer Top layer and bottom, top layer emissive material particle is less than bottom particle.Another kind of way is to be pressed emission layer before predecomposition System.Although these ways make moderate progress to emission of cathode layer surface roughness and flatness, transmitting layer surface is still not only It is sliding, there is certain geometrical defect, non-emissive layer surface has emitting substance to remain.The anti-particle bombardment poor performance of negative electrode, easily beats in work Fire, there is stray electrical current, affects negative electrode working stability degree and life-span.

The content of the invention

In order to solve the above-mentioned problems in the prior art, the invention provides a kind of strong anti-particle bombardment, long-life Oxide-coated cathode.

The technical solution used in the present invention is：A kind of oxide-coated cathode, specifically includes following steps and is prepared from：

A. cathode base metal is made：The several of 0.1～0.15mm are reserved when making cathode base metal in emission layer periphery surface What surplus；

B. emission layer is made：The nickel powder that particle mean size is 20～60 μm is poured in the negative electrode of step A preparation with mechanography On Base Metal, sintering 20min hydrogen flowing quantities >=0.4L/min at a temperature of 1250 ± 20 DEG C is integrally placed in hydrogen stove with mould, Dew point≤- 65 DEG C, sintrered nickel spongy layer, made by nickel sponge layer leave the geometry surplus of 0.3～0.4mm, nickel sponge layer cell size For 45%～50%, then cooling, the demoulding fill alkaline earth metal carbonate in nickel sponge layer, until alkaline earth metal carbonate not The stopping filling of nickel sponge layer is penetrated into again forms emission of cathode layer；

C. mechanical compaction emission layer：The surface of emission of emission of cathode layer made by mechanical compaction step B, pressure is（2.5± 0.1）×10⁶Pa, removes the geometry surplus of 0.2～0.25mm；

D. predecomposition is carried out to negative electrode before tubulature：Negative electrode is placed in hydrogen stove, at a temperature of 1050 ± 20 DEG C 5 are incubated ～8min, hydrogen flowing quantity >=0.4L/min, dew point≤- 65 DEG C are taken out after cooling；

E. lathe car system：The negative electrode that step D is obtained is clamped on lathe chuck, lathe chuck jerk value≤0.02mm, Car emission layer and periphery surface, remove remaining geometry surplus, then wipe most cathode surface adhesion particulate.

The invention has the beneficial effects as follows：The present invention is by the reserved geometry surplus of cathode surface, lathe car emission layer table Face and periphery cause cathode surface to become smooth regular, bright and clean clean.The hot particle angle of departure is reduced, launching electronics is limited close The deformation of degree distribution, improves the anti-particle bombardment ability of negative electrode, reduces emission of cathode face sparking probability, improves negative electrode work steady Fixed degree and life-span.

Description of the drawings

Fig. 1. the structural representation of the present invention；

Fig. 2. the emission layer of the sintering of the present invention；

Fig. 3. the emission layer exterior view after the sintering of the present invention；

Fig. 4. the side schematic view of Fig. 3 of the present invention；

Fig. 5. the structural representation of present invention compacting emission layer；

Fig. 6. the emission layer exterior view after present invention compacting；

Fig. 7. the side schematic view of Fig. 6 of the present invention；

Fig. 8. car system of the present invention launches the schematic diagram of layer surface；

Fig. 9. the emission layer exterior view after car system of the present invention；

Figure 10. the side schematic view of Fig. 8 of the present invention；

Figure 11. the emission layer service life curve comparison schematic diagram of the emission layer of car of the present invention and non-car.

Specific embodiment

A kind of oxide-coated cathode：1. it is reserved in emission layer periphery surface（0.1～0.15）The geometry surplus of mm, makes negative electrode （Tungsten base）Base Metal.Cathode base metal is cleaned, degassing processing.2. with mechanography by particle mean size be 40 μm（Minimum is not More than 20 μm, maximum is less than 60 μm）Nickel powder 1（Purity >=99.9%）It is poured on cathode base metal.Nickel powder 1 will have been irrigated Cathode base metal 3 be integrally placed in hydrogen stove with mould and sinter 20min at a temperature of (1250 ± 20) DEG C（Hydrogen flowing quantity >= 0.4L/min, dew point≤- 65 DEG C）, the demoulding after cooling.As shown in Fig. 2 made by nickel sponge layer surface should leave and be higher by Base Metal The geometry surplus of 0.3～0.4mm（The size for being actually higher by Base Metal should be that 0.3 described～0.4mm deducts emission layer periphery table The difference of 0.1 reserved～0.15mm of face）, cell size exists（45%～50%）Between（Fig. 2, Fig. 3, Fig. 4）.By prepare in proportion three First carbonate（BaCo₃、SrCo₃、CaCo₃）Solution is constantly equably coated on nickel sponge layer with writing brush, until carbonate 2 not Nickel sponge layer is penetrated into again.3. as shown in figure 5, pressure knot mould 4 in the presence of mechanical compaction, pressure：（2.5±0.1）×10⁶Pa is cloudy The pole surface of emission, removes 0.2～0.25mm surpluses.（Fig. 5, Fig. 6, Fig. 7）.4. predecomposition is carried out to negative electrode before tubulature：Oxide is cloudy Pole is made not predecomposition before emission layer and does not produce active material and can store for a long time, only namely uses front ability predecomposition in tubulature Active material is generated, this requires tubulature to use rapidly, to prevent active material to be in an atmosphere oxidized pollution failure；Dress Guan Qian, negative electrode is placed in hydrogen stove,（1050±20）It is incubated at a temperature of DEG C（5～8）min（Hydrogen flowing quantity >=0.4L/min, Dew point≤- 65 DEG C）, take out after cooling.5. negative electrode is clamped in on lathe chuck (jerk value≤0.02mm), in the work of lathe tool 5 With emission layer processed and the periphery surface of getting off, remaining geometry surplus is removed, make to be of the required size（Fig. 8, Fig. 9, Figure 10）.With dry Net hairbrush and silk wipe cathode surface residue away.By car negative electrode obtained in the present invention and non-car negative electrode obtained in traditional handicraft Carry out diode Experimental comparison（Cathode and anode spacing 1.5mm, in vacuum P≤1 × 10^-5Under conditions of Pa, decompose 30min, activation 2min, after seasoned 10min, chooses cathode temperature at 800 DEG C, and anode voltage tests emission current in 400V）（Figure 11）.The two Difference be：（1）Non- car negative electrode initial transmissions electric current is slightly larger, and this is because there is the transmitting evapotranspired on surface after non-car negative electrode predecomposition Thing is remained；And transmitting layer surface is rougher, there is slight spark phenomenon, thus it is mingled with slight stray electrical current.At the beginning of car negative electrode Beginning electric current is little, does not there is stray electrical current and spark phenomenon.（2）After 2600h, non-car the cathode current emission is declined slightly, after 3500h Less than the 80% of initial value, and car the cathode current emission is decreased obviously all the time, illustrates that car cathode life is cloudy higher than non-car Pole.Additionally, two kinds of negative electrodes are not detected by emission layer and have superheating phenomenon in experiment.

Claims

1. a kind of oxide-coated cathode, it is characterised in that：Specifically include following steps to be prepared from：

A. cathode base metal is made：The surplus of 0.1～0.15mm is reserved when making cathode base metal in emission layer periphery surface；

B. emission layer is made：The nickel powder that particle mean size is 20～60 μm is poured in the negative electrode fund of step A preparation with mechanography Be integrally placed at sintering in hydrogen stove with mould and prepare nickel sponge layer on category, made by nickel sponge layer leave the surplus of 0.3～0.4mm, Nickel sponge layer cell size is 45%～50%, and then cooling, the demoulding fill alkaline earth metal carbonate, until alkaline earth in nickel sponge layer Metal carbonate no longer penetrates into the stopping filling of nickel sponge layer and forms emission of cathode layer；

C. mechanical compaction emission layer：The surface of emission of emission of cathode layer made by mechanical compaction step B, removes 0.2～0.25mm's Surplus；

D. predecomposition is carried out to negative electrode before tubulature：Negative electrode is placed in hydrogen stove, at a temperature of 1050 ± 20 DEG C insulation 5～ 8min, hydrogen flowing quantity >=0.4L/min, dew point≤- 65 DEG C are taken out after cooling；

E. lathe car system：The negative electrode that step D is obtained is clamped on lathe chuck, lathe chuck jerk value≤0.02mm, car system Emission layer and periphery surface, remove remaining surplus, then wipe most cathode surface adhesion particulate.

2. a kind of oxide-coated cathode as claimed in claim 1, it is characterised in that：The moon of nickel powder will have been irrigated described in step B Pole Base Metal is integrally placed in hydrogen stove at a temperature of 1250 ± 20 DEG C with mould and sinters 20min, hydrogen flowing quantity >=0.4L/min, Dew point≤- 65 DEG C.

3. a kind of oxide-coated cathode as claimed in claim 1 or 2, it is characterised in that：Mechanical compaction negative electrode described in step B is sent out The pressure for penetrating face is（2.5±0.1）×10⁶Pa。