CN103987864A

CN103987864A - Tungsten alloy, tungsten alloy part using same, discharge lamp, transmission tube, and magnetron

Info

Publication number: CN103987864A
Application number: CN201280060241.4A
Authority: CN
Inventors: 中野佳代; 山本慎一; 堀江宏道
Original assignee: Toshiba Corp; Toshiba Materials Co Ltd
Current assignee: Toshiba Corp; Toshiba Materials Co Ltd
Priority date: 2012-01-07
Filing date: 2012-12-21
Publication date: 2014-08-13
Anticipated expiration: 2032-12-21
Also published as: CN103987864B; EP3763839A1; EP2801629B1; EP2801629A4; JPWO2013103100A1; WO2013103100A1; EP2801629A1; JP5881742B2

Abstract

The purpose of the invention is to obtain a tungsten alloy having emission characteristics equal to or greater than a tungsten alloy containing thorium, which is a radioactive substance, without using thorium; and to provide a transmission tube, a magnetron, and a discharge lamp in which the tungsten alloy is employed. This tungsten alloy contains an Hf moiety in an amount of 0.1 to 3 wt% inclusive, expressed as HfO2.

Description

Tungstenalloy and the tungstenalloy parts, discharge lamp, transmitting tube and the magnetron that use this tungstenalloy

Technical field

Embodiments of the present invention relate to tungstenalloy and use the tungstenalloy parts of this tungstenalloy, electrode for discharge lamp parts, discharge lamp, transmitting tube and magnetron.

Background technology

Tungstenalloy parts are used in field miscellaneous because of the hot strength of tungsten.For example,, as discharge lamp, transmitting tube, magnetron.In discharge lamp (HID lamp), tungstenalloy parts are used as cathode electrode, electrode support rod, coil component etc.In transmitting tube, tungstenalloy parts are used as filament or mesh grid etc.In magnetron, tungstenalloy parts are used as coil component etc.These tungstenalloy parts take to have regulation shape sintered compact, wire rod, wireform is become to the shape of the coil component of coiled type.

In the past, used the tungstenalloy that contains thorium (or thorium compound) recorded as Japanese Patent Laid-Open 2002-226935 communique (patent documentation 1) as these tungstenalloy parts.The tungstenalloy of patent documentation 1 is to make thorium particle and thorium compound particle below 0.3 μ m, carry out fine dispersion with median size, to improve the alloy of deformation resistance.The tungstenalloy of thoriated is because of the physical strength excellence under its emitter characteristic and high temperature, so be used in aforesaid field.

But, because thorium or thorium compound are radioactive substances, so consider the impact on environment, expect not use the tungstenalloy parts of thorium.In Japanese Patent Laid-Open 2011-103240 communique (patent documentation 2), develop and contain lanthanum boride (LaB ₆) tungstenalloy parts as the tungstenalloy parts that do not use thorium.

In addition, in patent documentation 3, recorded to have used and contained lanthanum trioxide (La ₂o ₃) and HfO ₂or ZrO ₂the short circuiting arc type high-pressure discharge lamp of tungstenalloy.The tungstenalloy of recording by patent documentation 3 can not obtain enough emission characteristics.This is because the fusing point of lanthanum trioxide is 2300 ℃ of left and right, lower, in raising, applies voltage or current density, and when parts reach a high temperature, lanthanum trioxide is evaporated long since, and emission characteristic declines.

Prior art document

Patent documentation

Patent documentation 1: Japanese Patent Laid-Open 2002-226935 communique

Patent documentation 2: Japanese Patent Laid-Open 2011-103240 communique

Patent documentation 3: No. 4741190 patent gazette of Japanese Patent

Summary of the invention

Invent technical problem to be solved

For example, the discharge lamp of one of tungstenalloy parts purposes is roughly divided into these two kinds of low-pressure discharge lamp and high-pressure discharge lamps.Low-pressure discharge lamp can enumerate general lighting, use special lighting in road or tunnel etc., the discharge lamp of the various arc-over types of the light cleaning device of paint solidification device, UV solidification equipment, sterilizing unit, semi-conductor etc. etc.In addition, high-pressure discharge lamp can be enumerated: the high voltage mercury lamp of the exposure apparatus of exterior lighting, UV solidification equipment, semi-conductor or the printed base plate etc. of the treatment unit of water supply and draining, general lighting, arena etc., wafer inspector, projector etc., metal halide lamp, ultrahigh pressure mercury lamp, xenon lamp, sodium vapor lamp etc.

Discharge lamp applies voltage more than 10V according to its purposes.The tungstenalloy that contains lanthanum boride that patent documentation 2 is recorded, to apply voltage less than 100V, just can obtain the life-span equal with the tungstenalloy of thoriated.But along with more than voltage increases to 100V, emission characteristic reduces, consequently the life-span also shortens greatly.

About transmitting tube and magnetron, exist too along with executing alive increase, can not obtain the problem of enough characteristics.

The present invention is the invention of carrying out in order to address the above problem, its object is to provide the thorium that is not used as radioactive substance, has the tungstenalloy of the identical or characteristic more than it of tungstenalloy with thoriated, use tungstenalloy parts, discharge lamp, transmitting tube and the magnetron of tungstenalloy.

The technical scheme that technical solution problem adopts

According to embodiment, a kind of W of containing composition is provided and is selected from Hf, HfO ₂, HfC and C the tungstenalloy of at least two or more compositions.Hf composition is with HfO ₂convert and count, in the scope below the above 3wt% of 0.1wt%.In addition,, according to embodiment, a kind of W of containing composition is provided and comprises HfO ₂the tungstenalloy of the Hf composition of particle.Hf composition is with HfO ₂convert and count, in the scope below the above 5wt% of 0.1wt%.HfO ₂the average primary particle diameter of particle is below 15 μ m.

The tungstenalloy parts of embodiment are to contain with HfO ₂conversion is counted in the tungstenalloy parts of Hf of 0.1～3wt%, contains Hf, HfO ₂, at least two or more in HfC, C.

In addition, from the content of Hf and O, be scaled HfO _xtime, be better x < 2.Content by Hf and O is scaled HfO _xtime, be better 0 < x < 2.

In addition, the carbon amount of the surface element of tungstenalloy parts being denoted as to C1 (wt%), when the carbon amount of central part is denoted as to C2 (wt%), is better C1 < C2.In addition be better to contain K, Si below 0.01wt% and at least one in Al.In addition,, when Hf content is denoted as to 100 mass parts, Zr content is better below 10 mass parts.In addition, the average crystallite particle diameter of tungsten is better 1～100 μ m.

In addition, be better for use for discharge lamp parts, parts for transmitting tube, magnetron at least one with parts.

In addition, the discharge lamp of embodiment is the discharge lamp that possesses the tungstenalloy parts of embodiment.In addition, the transmitting tube of embodiment is the transmitting tube that possesses the tungstenalloy parts of embodiment.In addition, the magnetron of embodiment is the magnetron that possesses the tungstenalloy parts of embodiment.

The feature of the electrode for discharge lamp parts of embodiment is: in the electrode for discharge lamp parts that formed by tungstenalloy, tungstenalloy contains with HfO ₂the Hf composition of 0.1～5wt% is counted in conversion, and HfO in Hf composition ₂the median size of particle is below 15 μ m.

In addition HfO, ₂the median size of particle more fortunately following the and maximum diameter of 5 μ m below 15 μ m.In addition, Hf composition is better with HfO ₂with two kinds of existence of metal Hf.In addition, Hf composition is better that metal Hf is present in HfO ₂the surface of particle.In addition, be better in Hf composition, part or all solid solution of metal Hf is in tungsten.In addition,, when the total content of Hf composition is denoted as to 100 mass parts, become HfO ₂the ratio of the Hf of particle is better 30～98 quality.In addition, tungstenalloy is better at least one dopant material forming in K, Si, Al containing below 0.01wt%.In addition, tungstenalloy is better at least one containing in Ti, Zr below 2wt%, V, Nb, Ta, Mo, rare earth element.In addition, wire diameter is better 0.1～30mm.In addition, the Vickers' hardness Hv of tungstenalloy is more fortunately in 330～700 scope.In addition, electrode for discharge lamp parts are better to have leading section and the columned main part of front end being made to cone-shaped.

In addition,, when observing the crystal structure in circumferential direction cross section of main part, the area occupation ratio of the tungsten crystallization of upper 1～80 μ m of per unit area 300 μ m * 300 μ m is better more than 90%.In addition,, when observing the crystal structure in side direction cross section of main part, the area occupation ratio of the tungsten crystallization of upper 2～120 μ m of per unit area 300 μ m * 300 μ m is better more than 90%.

In addition, the feature of the discharge lamp of embodiment is to have used the electrode for discharge lamp parts of embodiment.In addition, the voltage that applies of discharge lamp is better more than 100V.

The effect of invention

The tungstenalloy of embodiment is not because contain the thorium (comprising Thorotrast) as radioactive substance, so environment is not had to baneful influence.But also there is the identical or characteristic more than it of tungstenalloy with thoriated.Therefore, can will use tungstenalloy parts, electrode for discharge lamp parts, discharge lamp, transmitting tube, the magnetron of this tungstenalloy to make environment amenable goods.

Accompanying drawing explanation

Fig. 1 is the figure of an example that shows the tungstenalloy parts of the first embodiment.

Fig. 2 is the figure of other examples that shows the tungstenalloy parts of the first embodiment.

Fig. 3 is the figure of an example that shows the discharge lamp of the first embodiment.

Fig. 4 shows the figure of an example of parts for the magnetron of the first embodiment.

Fig. 5 is the figure of an example that shows the electrode for discharge lamp parts of the second embodiment.

Fig. 6 is the figure of other examples that shows the electrode for discharge lamp parts of the second embodiment.

Fig. 7 is the figure of an example in circumferential direction cross section of main part that shows the electrode for discharge lamp parts of the second embodiment.

Fig. 8 is the figure of an example in side surface direction cross section of main part that shows the electrode for discharge lamp parts of the second embodiment.

Fig. 9 is the figure of an example that shows the discharge lamp of the second embodiment.

Figure 10 is the figure that shows the alive relation of emission-Shi of embodiment 1 and comparative example 1.

Embodiment

(the first embodiment)

According to the first embodiment, a kind of W of containing composition is provided and is selected from Hf, HfO ₂, HfC and C the tungstenalloy of at least two or more compositions.Hf composition is with HfO ₂convert and count, in the scope below the above 3wt% of 0.1wt%.As the example of Hf composition, comprise Hf, HfO ₂, HfC.Hf composition is better to comprise Hf and HfO ₂.

The tungstenalloy parts of embodiment are with HfO ₂in the tungstenalloy parts of the Hf that the meter that converts contains 0.1～3wt%, contain Hf, HfO ₂, at least two or more in HfC and C.

By containing with HfO ₂(hafnia) converts and counts the Hf (hafnium) of 0.1～3wt%, can improve the characteristic of emission characteristic and intensity etc.That is, if Hf content with HfO ₂convert meter lower than 0.1wt%, and the effect of adding is inadequate, if surpass 3wt%, characteristic reduces.In addition, Hf component content is with HfO ₂preferably 0.5～2.5wt% of meter converts.

In addition the contained HfO of tungstenalloy, ₂in composition, must contain Hf, HfO ₂, at least two or more in HfC, C.That is, as HfO ₂composition, contains HfO with any in following array mode ₂composition: Hf and HfO ₂combination, HfO ₂and combination, the HfO of HfC (hafnium carbide) ₂and combination, Hf and the HfO of C (carbon) ₂combination, HfO with HfC ₂combination, Hf and HfO with HfC and C ₂combination, Hf and HfO with C ₂combination with HfC and C (carbon).If fusing point more separately, metal Hf is 2222 ℃, HfO ₂be 2758 ℃, HfC is 3920 ℃, and tungsten is 3400 ℃ (referring to < < Physicochemical topical reference book > > of Yan Bo bookstore (rock ripple Books shop)).The fusing point of metal thorium is 1750 ℃, Thorotrast (ThO ₂) fusing point be 3220 ± 50 ℃.Hafnium is compared with thorium, and fusing point is higher, so compare with the tungstenalloy of thoriated, can make hot strength identical or more than it.

In addition, from the content of Hf and O, be scaled HfO _xtime, be better x < 2.X < 2 means HfO contained in tungstenalloy ₂composition is not all with HfO ₂form exist, but its part forms metal Hf, HfC.The work function of metal Hf is 3.9, larger than the work function of metal Th 3.4, thus think that emission characteristic reduces, but in the purposes of use for discharge lamp etc., do not become significant problem.In addition, metal hafnium is because form sosoloid with tungsten, so be to carry high-intensity effective element.

From the content of Hf and O, be scaled HfO _xtime, be better 0 < x < 2.About x < 2, as previously mentioned.The meaning of 0 < x is as HfO contained in tungstenalloy ₂, there is any in HfC or C in composition.HfC or C have the deoxidation effect of removing the contained impurity oxygen of tungstenalloy.Because can reduce the resistance value of tungsten part by reducing impurity oxygen, so improve the characteristic as electrode.If within the scope of this, metal Hf, HfO ₂, HfC or C can balance exist, the characteristic in emission characteristic, intensity, resistance, life-span etc. improves.

In addition Hf, the HfO in tungstenalloy parts, ₂, HfC, O the measuring method of content adopt icp analysis method and rare gas element melting-infrared absorption.If adopt icp analysis method, can measure Hf amount and the HfO of Hf ₂measure with the Hf of HfC the Hf amount that adds up to and obtain.In addition, by rare gas element melting-infrared absorption, can measure HfO, _xo (oxygen) amount and the oxygen amount of Individual existence or the oxygen amount that exists as other oxide compounds add up to and must oxygen amount.In embodiment, by icp analysis method and rare gas element melting-infrared absorption mensuration Hf amount, O, measure, be converted into HfO _x.

In addition, also can contain K, Si below 0.01wt% and at least one in Al.K (potassium), Si (silicon), Al (aluminium) are so-called dopant materials, by adding these dopant materials, can improve recrystallization characteristic.By improving recrystallization characteristic, when carrying out recrystallization thermal treatment, just easily obtain uniform recrystallization tissue.In addition, for the lower limit of the content of dopant material, be not particularly limited, but preferably more than 0.001wt%.If less than 0.001wt%, the effect of interpolation can reduce; If surpass 0.01wt%, coking property and processibility meeting variation, production may decline.

In addition,, when Hf content is denoted as to 100 mass parts, Zr content is better below 10 mass parts.This Hf content represents Hf, HfO ₂hf amount with the total of HfC.The fusing point of Zr (zirconium) is up to 1855 ℃, so even if contain Zr in tungsten part, baneful influence is also few.In addition,, in commercially available Hf powder etc., according to the grade of powder, also can comprise the Zr of several percentage points.High purity Hf powder or the high purity HfO of impurity removed in use ₂powder is effective improving in characteristic.But the high purity of raw material changes into the principal element rising into cost.When Hf is denoted as to 100 weight part, if Zr (zirconium) content is below 10 mass parts, can not make characteristic excessive descent.

In addition, the carbon amount of the surface element of tungstenalloy parts being denoted as to C1 (wt%), when the carbon amount of central part is denoted as to C2 (wt%), is better C1 < C2.Surface element represents to start till the part of 20 μ m from the surface of tungstenalloy.In addition, central part refers to the centre portions in the cross section of tungstenalloy parts.In addition, this carbon amount be by the carbon of carbide of HfC etc. and the two total of the carbon of Individual existence and value, by burning-infrared absorption, analyze.The carbon of the carbon amount C2 presentation surface portion of the carbon amount C1 < central part of surface element becomes CO by deoxidation ₂, and go to outside system.In addition, the carbon amount of surface element reduces the relative state increasing of Hf amount that represents to become surface element.For this reason, while using Hf as emitter-base bandgap grading material, effective especially.

In addition, the average crystallite particle diameter of tungsten is better 1～100 μ m.Tungstenalloy parts are sintered compact preferably.Sintered compact if, by utilizing forming process can make the parts of shape of all kinds.By implementing forging process, calendering procedure, wire-drawing process etc., easily sintered compact is processed into wire rod (comprising filament) and coil component etc.

In addition, tungsten crystallization, when being sintered compact, is long-width ratio less than 3 crystallization at more than 90% isotropy crystal structure.In addition,, if carry out Wire Drawing, form long-width ratio and be more than 3 crystallization at more than 90% flat crystal structure.In addition, the method for calculation of the particle diameter of tungsten crystallization are to utilize the enlarged photograph of metalloscope etc. to take crystal structure.For the tungsten crystallization showing herein, measure maximum Fu Leite diameter (Japanese: maximum Off ェレー footpath), using it as particle diameter.To arbitrarily 100 carry out this operation, using its mean value as average crystallite particle diameter.

In addition, if the mean value of the maximum Fu Leite diameter of tungsten crystallization is less than 1 μ m, more difficult Hf, the HfO of making ₂, HfC or C dispersion component reach uniform dispersion state.Dispersion component is present on the crystal boundary between tungsten crystallization.Therefore, if the mean value of the maximum Fu Leite diameter of tungsten crystallization is little, arrive lower than 1 μ m, crystal boundary diminishes, and is difficult to make dispersion component dispersed.On the other hand, if the mean value of the maximum Fu Leite diameter of tungsten crystallization is greatly to surpassing 100 μ m, as the strength degradation of sintered compact.Therefore, the mean value of the maximum Fu Leite diameter of tungsten crystallization is better 1～100 μ m, is more preferably 10～60 μ m.

In addition, from homodisperse viewpoint, consider Hf, HfO ₂, HfC or C the mean value of maximum Fu Leite diameter of dispersion component be better the mean value that is less than the maximum Fu Leite diameter of tungsten.In addition, the mean value of the maximum Fu Leite diameter of tungsten crystallization is denoted as to A (μ m), when the mean value of the maximum Fu Leite diameter of dispersion component is denoted as to B (μ m), is better B/A≤0.5.Hf, HfO ₂, HfC or C dispersion component be present in the crystal boundary between tungsten crystallization, play the function of emitter-base bandgap grading material and grain-boundary strengthening material.By the median size of dispersion component being reduced to below 1/2 of average crystallite particle diameter of tungsten, can make dispersion component easily be dispersed in tungsten crystal grain boundary, reduce the uneven of characteristic.

Aforesaid tungstenalloy parts are used on use for discharge lamp parts, at least a kind of parts for parts for transmitting tube, magnetron.

As use for discharge lamp parts, can enumerate discharge lamp cathode electrode used, electrode support rod, coil component.Fig. 1 and Fig. 2 have shown an example of use for discharge lamp cathode electrode.In figure 1 is cathode electrode, and 2 is electrode body portion, 3 leading sections that are electrode.Cathode electrode 1 is formed by the sintered compact of tungstenalloy.In addition, the front end of electrode leading section 3 can be the trapezoidal shape shown in Fig. 1 (circular cone shape), can be also the triangular shape shown in Fig. 2 (cone shape).As required, leading section is carried out to attrition process.In addition, electrode body portion 2 is better the cylindric of diameter 2～35mm, and the length of electrode body portion 2 is better 10～600mm.

Fig. 3 has shown an example of discharge lamp.In figure, 1 is cathode electrode, and 4 is discharge lamp, and 5 is electrode support rod, and 6 is Glass tubing.In discharge lamp 4, so that electrode leading section mode in opposite directions configures a pair of cathode electrode 1.Cathode electrode 1 engages with electrode support rod 5.In addition, in the inside of Glass tubing 6, be provided with not shown luminescent coating.In addition, in the inside of Glass tubing, enclose mercury, halogen, argon gas (or neon) etc. as required.In addition, the tungstenalloy parts of embodiment are as in the situation of electrode support rod 5, can whole electrode support rod the tungstenalloy that is embodiment, can be also the tungstenalloy that the part that engages with cathode electrode is used embodiment, and the shape that remainder engages with other lead materials.

In addition,, according to the kind of discharge lamp, also exist coil component is arranged on to the discharge lamp using as electrode on electrode support rod.Also can use the tungstenalloy of embodiment as this coil component.

In addition, the discharge lamp of embodiment is to have used the tungstenalloy of embodiment or the discharge lamp of tungstenalloy parts.Kind for discharge lamp is not particularly limited, and goes for any in low-pressure discharge lamp and high-pressure discharge lamp.In addition, low-pressure discharge lamp can enumerate general lighting, use special lighting in road or tunnel etc., the discharge lamp of the various arc-over types of the light cleaning device of paint solidification device, UV solidification equipment, sterilizing unit, semi-conductor etc. etc.In addition, high-pressure discharge lamp can be enumerated: the high voltage mercury lamp of the exposure apparatus of exterior lighting, UV solidification equipment, semi-conductor or the printed base plate etc. of the treatment unit of water supply and draining, general lighting, arena etc., wafer inspector, projector etc., metal halide lamp, ultrahigh pressure mercury lamp, xenon lamp, sodium vapor lamp etc.

In addition, the tungstenalloy parts of embodiment are also applicable to parts as transmitting tube.As transmitting tube parts, enumerate filament or mesh grid.In addition, mesh grid can be that wire rod is woven to webbed mesh grid, can be also on sintered compact plate, to be formed with the mesh grid in a plurality of holes.The transmitting tube of embodiment is because used the tungstenalloy parts of embodiment as transmitting tube parts, so emission characteristic etc. are more satisfactory.

In addition, the tungstenalloy parts of embodiment are also applicable to parts as magnetron.As magnetron parts, can enumerate coil component.Fig. 4 has shown the magnetron cathode structure body by an example of parts as magnetron.In figure, 7 is coil component, and 8 is upper support parts, and 9 is lower support parts, and 10 is support rod, and 11 is magnetron cathode structure body.Upper support parts 8 and lower support parts 9 become one by support rod 10.The surrounding of support rod 10 disposes coil component 7, becomes one with upper support parts 8 and lower support parts 9.Such magnetron is suitable for microwave oven with parts.The wire diameter of the tungsten wire rod that in addition, coil component is used is better 0.1～1mm.Diameter as coil component is better 2～6mm.When the tungstenalloy parts that use embodiment are used parts as magnetron, show excellent emission characteristic and hot strength.For this reason, can improve the reliability of the magnetron that has used tungstenalloy parts.

Then, the manufacture method of the tungstenalloy of embodiment and tungstenalloy parts is described.As long as the tungstenalloy of embodiment and tungstenalloy parts have aforesaid structure, its manufacture method is not just had to specific restriction, as efficient manufacture method, can exemplify following method.

First prepare the tungsten powder as raw material.The median size of tungsten powder is 1～10 μ m preferably.If median size is less than 1 μ m, the easy aggegation of tungsten powder, is difficult to make HfO ₂composition is dispersed.If surpass 10 μ m, as the average crystallite particle diameter of sintered compact, likely surpass 100 μ m.In addition, purity is different and different according to target purposes, but be better 99.0wt% above, be more preferably high-purity tungsten powder more than 99.9wt%.

Then, prepare as HfO ₂the HfO of composition ₂powder.In addition, prepare the HfC powder as HfC composition.Also can replace with the mixture of Hf powder and carbon dust HfC powder.In addition, also can not use separately HfC powder, but use the powder that has mixed Hf powder or carbon dust 1～2 kind and obtain in HfC powder.Wherein, be better to use HfO ₂powder or HfC powder.HfC powder is in sintering circuit, and a part of carbon decomposes, and reacts with the impurity oxygen in tungsten powder, generates carbonic acid gas, is discharged into beyond system, and the homogenizing of tungstenalloy is had to contribution, so comparatively desirable.In the situation that use the mixed powder of Hf powder and carbon dust, must by Hf powder and carbon dust, the two evenly mix, so the load of manufacturing process increases.In addition, because metal Hf is easily oxidized, so better use HfC powder.

In addition HfO, ₂the median size of composition powder is better 0.5～5 μ m.If median size is less than 0.5 μ m, HfO ₂the aggegation of powder increases, and is difficult to make it dispersed.In addition,, if surpass 5 μ m, be difficult to make it dispersed on the crystal boundary of tungsten crystallization.In addition, the median size of HfC composition powder is better 0.5～5 μ m.If median size is less than 0.5 μ m, the aggegation of HfC powder increases, and is difficult to make it dispersed.In addition,, if surpass 5 μ m, be difficult to make it dispersed on the crystal boundary of tungsten crystallization.In addition if consider from homodisperse viewpoint, be better HfO, ₂the median size of the median size≤tungsten powder of powder or HfC powder.

In addition, by HfO ₂when the Hf amount of powder, HfC powder or Hf powder is denoted as 100 mass parts, Zr is better below 10 mass parts.Sometimes have Zr composition and be included in HfO as impurity ₂situation in powder, HfC powder or Hf powder.If with respect to Hf amount, Zr measures below 10 mass parts, can not hinder Hf composition for the benefit of characteristic.In addition, Zr amount is more few better, but the high purity meeting of raw material becomes the principal element that cost rises.Therefore, Zr amount is more preferably the scope of 0.1～3 mass parts.

In addition, as required, can add more than one the dopant material that is selected from K, Si, Al.Its addition is preferably below 0.01wt%.

Then each raw material powder is evenly mixed.Mixed processes is better used the mixing machine of ball mill etc. to carry out.Mix engineering and be better carry out 8 hours above, be more preferably more than 20 hours.In addition, as required, also can be mixed and made into slurry with organic binder bond, organic solvent.In addition, also can carry out granulating working procedure as required.

Then with mould, make molding.As required molding is carried out to degreasing process.Then, carry out sintering circuit.Sintering circuit is better to carry out in the inert atmosphere of hydrogen, nitrogen etc. or vacuum.In addition, sintering condition is better to carry out 1～20 hour at 1400～3000 ℃ of temperature.If sintering temperature is less than 1400 ℃ or sintering time less than 1 hour, sintering is insufficient, the strength degradation of sintered compact.In addition, if sintering temperature surpasses 3000 ℃ or sintering time, surpass 20 hours, tungsten crystallization excessively grain grow.In addition, by carry out sintering in hydrogen, inert atmosphere or vacuum, the carbon of sintered compact surface element easily can be discharged into outside system.In addition, sintering circuit is resistance sintering, normal pressure-sintered, pressure sintering etc., and this is not particularly limited.

Then, carry out sintered compact (tungstenalloy) to be processed as the operation of parts.As for being processed into the operation of parts, can exemplify forging process, calendering procedure, wire-drawing process, cutting action, grinding step etc.In addition,, when being processed as coil component, can exemplify coiling operation (Japanese: コイリ Application グ engineering).In addition,, when making is used the mesh grid of parts as transmitting tube, can exemplify filament is processed to webbed operation.

Then,, after to component processing, correct as required thermal treatment.Correct thermal treatment carries out in inert atmosphere or vacuum more fortunately within the scope of 1300～2500 ℃.By correcting thermal treatment, can relax the internal stress producing in the operation that is processed into parts, to improve the intensity of parts.

(the second embodiment)

According to the second embodiment, a kind of W of containing composition is provided and comprises HfO ₂the tungstenalloy of the Hf composition of particle.Hf composition is with HfO ₂convert and count, in the scope below the above 5wt% of 0.1wt%.HfO ₂the average primary particle diameter of particle is below 15 μ m.

The feature of the electrode for discharge lamp parts of embodiment is: in the electrode for discharge lamp parts that formed by tungstenalloy, tungstenalloy contains with HfO ₂the Hf composition of 0.1～5wt% is counted in conversion, and HfO in Hf composition ₂the median size of the primary particle of particle is below 15 μ m.

Fig. 5 and Fig. 6 have shown an example of the electrode for discharge lamp parts of embodiment.In figure, the 21st, electrode for discharge lamp parts, the 22nd, there are the electrode for discharge lamp parts of the leading section of taper, the 23rd, leading section, the 24th, main part.Electrode for discharge lamp parts 21 are cylindric, and its leading section 23 is processed as to taper, form electrode for discharge lamp parts 22.Be processed as taper electrode for discharge lamp parts 21 before and be generally cylindrical shape, but also can be quadrangular shape.

First, tungstenalloy contains with HfO ₂the Hf composition of 0.1～5wt% is counted in conversion.Hf composition can exemplify HfO ₂, these two kinds of Hf.HfO ₂in the situation of (hafnia), the atomic ratio of O/Hf is not limited to 2, and the atomic ratio that can comprise O/Hf is at the material of 1.6～2 scope.In addition, Hf composition is with HfO ₂(O/Hf atomic ratio=2) are converted and are counted the composition that contains of 0.1～5wt%.Hf composition is the composition playing a role as emitter-base bandgap grading material in electrode for discharge lamp parts.The content of Hf composition is with HfO ₂convert while counting less than 0.1wt%, emission characteristic is inadequate.On the other hand, if surpass 5wt%, likely cause strength degradation etc.Therefore, Hf composition is with HfO ₂it is 0.3～3.0wt% that conversion is haggled over, and is more preferably 0.5～2.5wt%.

In addition, Hf composition is as previously mentioned as HfO ₂or Hf exists.Wherein, HfO ₂primary particle must be that median size is the particle below 15 μ m., HfO importantly ₂for HfO ₂particle.HfO ₂particle is present on the crystal boundary between tungsten crystalline particle.For this reason, if HfO ₂particle is excessive, and the gap between tungsten crystalline particle can increase, and becomes the reason of density decline and strength degradation.In addition, if be present on the crystal boundary between tungsten crystalline particle HfO ₂particle not only plays the function of emissive material, can also play the function of dispersion-strengthened material, so also can obtain the intensity of electrod assembly, improves.

In addition HfO, ₂the median size of the primary particle of particle more fortunately following the and maximum diameter of 5 μ m below 15 μ m.In addition HfO, ₂the median size of particle is better 0.1～3 μ m.In addition, maximum diameter is more fortunately below 1～10 μ m.In median size less than 0.1 μ m or maximum diameter the little HfO less than 1 μ m ₂in the situation of particle, because the consumption that transmitting produces can run out of early.In order to extend the life-span as electrode, be better HfO ₂the median size of particle more than 0.1 μ m or maximum diameter more than 1 μ m.

In addition HfO, ₂dispersion of particles state is better: on the arbitrary line of 200 μ m, have 2～30 HfO ₂the scope of particle.If HfO ₂the number of particle on every 200 μ m straight lines less than 2 (0～1), subregion HfO ₂particle tails off, and the ununiformity of transmitting increases.On the contrary, if HfO ₂the number of particle nearly surpasses 30 (more than 31), the HfO of subregion on every 200 μ m straight lines ₂particle is too much, likely occurs the baneful influence of strength degradation etc.In addition, HfO ₂the measuring method of dispersion of particles state is by the arbitrary section of tungstenalloy is carried out to bust shot.The multiplying power of enlarged photograph is more than 1000 times.The arbitrary line (line rugosity 0.5mm) of drawing 200 μ m on enlarged photograph, calculates existing HfO on this line ₂the number of particle.

In addition HfO, ₂the maximum diameter of the offspring of particle is more fortunately below 100 μ m.HfO ₂the offspring of particle refers to the agglomeration of primary particle.If offspring is greatly to surpassing 100 μ m, the intensity of tungstenalloy parts can decline.For this reason, HfO ₂the maximum diameter of the offspring of particle, below 100 μ m, below 50 μ m, is better small enough to below 20 μ m more fortunately.

In addition,, in Hf composition, there is dispersion state miscellaneous in Hf (metal Hf).

The first dispersion state is the state existing as metal Hf particle.Metal Hf particle and HfO ₂particle is same, is present on the crystal boundary between tungsten crystalline particle.By being present on the crystal boundary between tungsten crystalline particle, metal Hf particle also plays the function of emissive material and dispersion-strengthened material.For this reason, the median size of the primary particle size of metal Hf particle below 15 μ m, better, below 10 μ m, is further more preferably 0.1～3 μ m more fortunately.In addition, maximum diameter is more fortunately below 15 μ m, better below 10 μ m.In addition, about metal Hf particle, when making tungstenalloy, can adopt in advance by HfO, ₂the method of particle and metal Hf mix particles, also can adopt in manufacturing process HfO ₂particle carries out the method for deoxidation.If use the method for deoxidation, the oxygen that also can obtain in tungsten is released into the effect outside system, so comparatively desirable.If can deoxidation, can reduce the resistance of tungstenalloy, so can improve the electroconductibility as electrode.

The second dispersion state is that metal Hf is present in HfO ₂the surperficial state of particle.Identical with the first dispersion state, when making the sintered compact of tungstenalloy, oxygen is from HfO ₂particle surface deoxidation, is formed on the state that surface is formed with metal Hf tunicle.Even the HfO with metal Hf tunicle ₂particle, also shows excellent emission characteristic.In addition, with the HfO of metal Hf tunicle ₂the median size of the primary particle size of particle below 15 μ m, better, below 10 μ m, is further more preferably 0.1～3 μ m more fortunately.In addition, maximum diameter is more fortunately below 15 μ m, better below 10 μ m.

The 3rd dispersion state is that part or all of metal Hf is solid-solubilized in the state in tungsten.Metal Hf forms the combination of sosoloid with tungsten.By forming sosoloid, can improve the intensity of tungstenalloy.In addition, have or not the measuring method of solid solution to be undertaken by XRD analysis.First, measure the content of Hf composition and oxygen.In addition, the amount of the Hf from Hf composition and oxygen amount are carried out HfO ₂convert, confirm HfO _xx < 2.Then, carry out the peak that XRD analysis confirmation does not detect metal Hf.Although HfO _x, x < 2, to become the hafnium of hafnia, do not exist, the peak that does not detect metal Hf means that metal Hf solid solution is in tungsten.

On the other hand, HfO _x, x < 2, to become the hafnium of hafnia, do not exist, and detected the peak of metal Hf, being meant to be metal Hf does not have solid solution but is present in the first dispersion state on the crystal boundary between tungsten crystallization.In addition, the second dispersion state can be by being used EPMA (electron probe microanalyzer) or TEM (transmission electron microscope) to analyze.

The dispersion state of metal Hf can be any one or the two or more combination in the first dispersion state, the second dispersion state, the 3rd dispersion state.

In addition,, when the total content of Hf composition (Hf content) is denoted as to 100 mass parts, become HfO ₂the ratio of the Hf of particle is better 30～98 mass parts.Certainly, Hf composition can be also all HfO ₂particle.If HfO ₂particle just can obtain emission characteristic.On the other hand, by metal Hf is disperseed, can improve electroconductibility and the intensity of tungstenalloy.But if the whole of Hf are metal Hf, emission characteristic and hot strength reduce.The fusing point of metal Hf is 2230 ℃, HfO ₂fusing point be 2758 ℃, the fusing point of tungsten is 3400 ℃.Because HfO ₂fusing point higher, so contain HfO with specified amount ₂the hot strength of tungstenalloy improve.In addition HfO, ₂surface current density and ThO ₂about equally, so the same electric current of tungstenalloy negotiable and containing Thorotrast.Therefore, even as discharge lamp, also can be with corresponding containing the same current density of the tungsten alloy electrode of Thorotrast, so do not need to change the design of pilot circuit etc.Therefore, when the total content of Hf composition is denoted as to 100 mass parts, HfO ₂the ratio of particle is better 30～98 mass parts.Further be more preferably 60～95 mass parts.

In addition, analyze HfO ₂with the method for the content of metal Hf be that the total Hf measuring in tungstenalloy by icp analysis method measures.Then, by melt-infrared absorption of rare gas element, measure the total oxygen demand in tungstenalloy.In the situation that tungstenalloy is the binary system forming with Hf composition, can think that measured total oxygen demand in fact all becomes HfO ₂.Therefore, according to measured total Hf amount and the comparison of total oxygen demand, the HfO in the Hf composition that can survey ₂amount.Adopt in the situation of the method, with O/Hf=2, calculate HfO ₂amount.

In addition HfO, ₂the mensuration of the size of particle is measured by following method: at the arbitrary section photographs enlarged photograph of tungstenalloy sintered compact, by the HfO wherein demonstrating ₂the longest diagonal lines of particle is as HfO ₂the particle diameter of particle.Carry out this operation, measure 50 HfO ₂particle, using its mean value as HfO ₂the median size of particle.In addition, by HfO ₂maximum value in the particle diameter of particle (the longest diagonal lines) is as HfO ₂the maximum diameter of particle.

In addition, tungstenalloy can contain at least one dopant material forming in K, Si, Al below 0.01wt%.K (potassium), Si (silicon), Al (aluminium) are so-called dopant materials, by adding these dopant materials, can improve recrystallization characteristic.By improving recrystallization characteristic, when carrying out recrystallization thermal treatment, just easily obtain uniform recrystallization tissue.In addition, for the lower limit of the content of dopant material, be not particularly limited, but preferably more than 0.001wt%.If less than 0.001wt%, the effect of interpolation can reduce; If surpass 0.01wt%, coking property and processibility meeting variation, production declines.

In addition, tungstenalloy can contain and is selected from least one of Ti, Zr, V, Nb, Ta, Mo and rare earth element below 2wt%.Ti, Zr, V, Nb, Ta, Mo, rare earth element can adopt respectively any form in metal simple-substance, oxide compound, carbide.In addition, also can contain two or more.Even if containing two or more in the situation that, its total amount is also more fortunately below 2wt%.These contain the function that composition mainly plays dispersion-strengthened material.HfO ₂particle is because play the function of emissive material, so if use for a long time discharge lamp to be consumed gradually.A little less than the emission characteristic of Ti, Zr, V, Nb, Ta, Mo, rare earth element, thus because the consumption that causes of transmitting is few, can long term maintenance as the function of dispersion-strengthened material.Lower limit for content is not particularly limited, but more fortunately more than 0.01wt%.In addition in these compositions, be better Zr, rare earth element.These compositions are atomic radius thick atoms more than 0.16nm, so be the composition that surface current density is large.In other words, the metal simple-substance or its compound that contain the element of atomic radius more than 0.16nm are better.

In addition, electrode for discharge lamp parts are better to have leading section and the columned main part of front end being made to cone-shaped.By forming taper, form the shape that leading section is fined away and just can improve as the characteristic of electrode for discharge lamp parts.As shown in Figure 6, for the length ratio of leading section 23 and main part 24, be not particularly limited, can set according to purposes.

In addition the wire diameter φ of electrode for discharge lamp parts 0.1～30mm preferably.If less than 0.1mm, can not there is the intensity as electrod assembly, in the time of in being assembled into discharge lamp, likely fracture, or when leading section is processed as to taper, likely fracture.If large when surpassing 30mm, as after chat like that, the homogeneity of control tungsten crystal structure becomes difficult.

In addition,, when observing the crystal structure in circumferential direction cross section (cross section) of main part, on per unit area 300 μ m * 300 μ m, crystallization particle diameter is that the area occupation ratio of the tungsten crystallization of 1～80 μ m is better more than 90%.Fig. 7 has shown an example in the circumferential direction cross section of main part.In figure, the 24th, main part, the 25th, circumferential direction cross section.When measuring the crystal structure in circumferential direction cross section, the central cross-section of the length of main part is taken pictures in the mode of macrophotography.In addition, in the time of cannot analytical unit area 300 μ m * 300 μ m in, the visual field thin in wire diameter, can take repeatedly circumferential direction cross section arbitrarily.In enlarged photograph, using the long-diagonal of the tungsten crystalline particle wherein showing as maximum diameter, measure the area % of the tungsten crystalline particle of this maximum diameter in the scope of 1～80 μ m.

The tungsten crystallization in the circumferential direction cross section of main part crystallization particle diameter on per unit area is that the area occupation ratio of the tungsten crystallization of 1～80 μ m more than 90% is representing that crystallization particle diameter is less than the little tungsten crystallization of 1 μ m and few over the large tungsten crystallization of 80 μ m.If the tungsten crystallization less than 1 μ m is too much, the crystal boundary between tungsten crystalline particle can become too small.HfO in crystal boundary ₂if the ratio of particle increases, at the HfO because launch ₂when particle consumes, become large defect, the strength decreased of tungstenalloy.On the other hand, if it is many to surpass the large tungsten crystalline particle of 80 μ m, crystal boundary becomes excessive, the strength degradation of tungstenalloy.Be more preferably the area occupation ratio of tungsten crystallization of 1～80 μ m more than 96%, being further more preferably area occupation ratio is 100%.

In addition, the median size of the tungsten crystalline particle in circumferential direction cross section is more fortunately below 50 μ m, better below 20 μ m.In addition, the mean aspect ratio of tungsten crystalline particle is to be better less than 3.In addition, when measuring long-width ratio, take the enlarged photograph of unit surface 300 μ m * 300 μ m, using the maximum diameter (Fu Leite diameter) of the tungsten crystalline particle wherein showing as major diameter L, the particle diameter that central vertical from major diameter L is extended is as minor axis S, using major diameter L/ minor axis S as long-width ratio.Carry out this operation to 50, using its mean value as mean aspect ratio.In addition, while calculating median size, by (major diameter L+ minor axis S)/2 as particle diameter, using the mean value of 50 as median size.

In addition,, when observing the crystal structure in side surface direction cross section (vertical section) of main part, on per unit area 300 μ m * 300 μ m, crystallization particle diameter is that the area occupation ratio of the tungsten crystallization of 2～120 μ m is better more than 90%.Fig. 8 has shown an example in side surface direction cross section.In figure, the 24th, main part, the 26th, side surface direction cross section.When measuring the crystal structure in side surface direction cross section, measure the cross section at the center of the wire diameter of passing through main part.In addition, in the time of cannot analytical unit area 300 μ m * 300 μ m in a visual field, can take repeatedly side surface direction cross section arbitrarily.In enlarged photograph, using the long-diagonal of the tungsten crystalline particle wherein showing as maximum diameter, measure the area % of the tungsten crystalline particle of this maximum diameter in the scope of 2～120 μ m.

The tungsten crystallization in the side surface direction cross section of main part crystallization particle diameter on per unit area is that the area occupation ratio of the tungsten crystallization of 2～120 μ m more than 90% is representing that crystallization particle diameter is less than the little tungsten crystallization of 2 μ m and few over the large tungsten crystallization of 120 μ m.If the tungsten crystallization less than 2 μ m is too much, the crystal boundary between tungsten crystalline particle can become too small.HfO in crystal boundary ₂if the ratio of particle increases, at the HfO because launch ₂when particle consumes, become large defect, the strength decreased of tungstenalloy.On the other hand, if it is many to surpass the large tungsten crystalline particle of 120 μ m, crystal boundary becomes excessive, the strength degradation of tungstenalloy.Be more preferably the area occupation ratio of tungsten crystallization of 2～120 μ m more than 96%, being further more preferably area occupation ratio is 100%.

In addition, the median size of the tungsten crystalline particle in side surface direction cross section is more fortunately below 70 μ m, better below 40 μ m.In addition, the mean aspect ratio of tungsten crystalline particle is more fortunately more than 3.The measuring method of median size and mean aspect ratio is identical with circumferential direction cross section.

As mentioned above, by controlling the size of tungsten crystalline particle, size and the ratio of Hf composition, can provide the especially tungstenalloy of hot strength of discharge characteristic excellence and intensity.Therefore, the characteristic of electrode for discharge lamp parts also improves.

In addition, the relative density of tungstenalloy is better more than 95.0%, to be more preferably more than 98.0%.If relative density is less than 95.0%, bubble increases, and likely produces the baneful influence of strength degradation and partial discharge etc.In addition, the account form of relative density is the value that the actual density based on Archimedes's method is obtained divided by theoretical density., (actual density/theoretical density) * 100 (%)=relative density.In addition about theoretical density, be the theoretical density 19.3g/cm as tungsten, ³, hafnium theoretical density 13.31g/cm ³, hafnia theoretical density 9.68g/cm ³, according to mass ratio separately by calculating the value of trying to achieve.For example,, at the HfO by 1wt% ₂, the Hf of 0.2wt% is, in situations of tungstenalloy that all the other form for tungsten, theoretical density is 9.68 * 0.01+13.31 * 0.002+19.3 * 0.988=19.19182g/cm ³.In addition,, while calculating theoretical density, can not consider the existence of impurity.

In addition, the Vickers' hardness Hv of tungstenalloy is more fortunately more than 330.Hv is better in 330～700 scope.If Vickers' hardness Hv is less than 330, tungstenalloy is too soft, strength decreased.On the other hand, if Hv surpasses 700, tungstenalloy is really up to the mark, is difficult to leading section to be processed into cone-shaped.In addition, if really up to the mark, in the situation that main body minister's electrod assembly there is no flexibility and likely easily fracture.In addition, can make 3 flexural strengths of tungstenalloy up to more than 400MPa.

In addition, the surface roughness Ra of electrode for discharge lamp parts is more fortunately below 5 μ m.Particularly, about leading section, surface roughness Ra below 5 μ m, is more preferably little to 3 μ m more fortunately.If concave-convex surface is large, emission characteristic declines.

If electrode for discharge lamp parts as above, applicable to discharge lamp miscellaneous.Therefore, even if impose, apply voltage up to voltage more than 100V, also can realize the long lifetime.In addition, not limit by the use system of foregoing low-pressure discharge lamp and high-pressure discharge lamp etc.In addition, the wire diameter of main part can be 0.1～30mm, from wire diameter, is the thin size below the above 3mm of 0.1mm, surpasses 3mm and the middle size below 10mm, to surpassing 10mm and the thick line footpath below 30mm, is all suitable for.In addition, the length of electrode body portion is better 10～600mm.

Fig. 9 has shown an example of discharge lamp.In figure, 22 is electrod assembly (leading section being carried out to taper processing), and 27 is discharge lamp, and 28 is electrode support rod, and 29 is Glass tubing.In discharge lamp 27, so that electrode leading section mode in opposite directions configures pair of electrodes parts 22.Electrod assembly 22 engages with electrode support rod 28.In addition, the inner face at Glass tubing 29 is provided with not shown luminescent coating.In addition, in the inside of Glass tubing, enclose mercury, halogen, argon gas (or neon) etc. as required.

In addition, the discharge lamp of embodiment is to have used the tungstenalloy of embodiment or the discharge lamp of electrod assembly.Kind for discharge lamp is not particularly limited, and goes for any in low-pressure discharge lamp and high-pressure discharge lamp.In addition, low-pressure discharge lamp can enumerate general lighting, use special lighting in road or tunnel etc., the discharge lamp of the various arc-over types of the light cleaning device of paint solidification device, UV solidification equipment, sterilizing unit, semi-conductor etc. etc.In addition, high-pressure discharge lamp can be enumerated: the high voltage mercury lamp of the exposure apparatus of exterior lighting, UV solidification equipment, semi-conductor or the printed base plate etc. of the treatment unit of water supply and draining, general lighting, arena etc., wafer inspector, projector etc., metal halide lamp, ultrahigh pressure mercury lamp, xenon lamp, sodium vapor lamp etc.In addition, because improved the intensity of tungstenalloy, so also can be applicable to if automobile is with the field of following mobile (vibration) discharge lamp.

Then, manufacture method is described.As long as the tungstenalloy of embodiment and electrode for discharge lamp parts have aforesaid structure, its manufacture method is just not particularly limited, as the manufacture method of efficient acquisition goods, can exemplify following method.

First, as the manufacture method of tungstenalloy, the preparation of the tungsten alloy powder that contains Hf composition.

First, prepare the HfO as Hf composition ₂powder.HfO ₂the median size of the primary particle size of particle below 15 μ m, is more preferably median size below 5 μ m more fortunately.In addition be better that the particle that uses sieve in advance maximum diameter to be surpassed to 15 μ m is removed.In addition, wanting to make maximum diameter, to use and there is the large HfO of screening out of target mesh size when following at 10 μ m ₂particle.In addition, at the HfO that wants to remove small particle size ₂during particle, also use the sieve with target mesh size to remove.In addition before sieving, be better to utilize ball mill etc. to HfO, ₂particle carries out pulverizing process.By carrying out pulverizing process, can destroy agglomeration, so the particle diameter easily carrying out based on sieving is controlled.

Then, carry out the operation of hybrid metal tungsten powder.In addition, the median size of tungsten powder is better 0.5～10 μ m.In addition, can be tungsten purity more than 98.0wt%, oxygen level below 1wt%, the tungsten powder of foreign metal composition below 1wt%.In addition, with HfO ₂particle is same, is better the operation by utilizing in advance ball mill etc. to pulverize, sieve, and removes in advance small-particle and macroparticle.

At HfO ₂during conversion, to reach the Hf of target, become component (HfO ₂conversion 0.1～5wt%) condition is added tungsten powder.By HfO ₂the mixed powder of particle and tungsten powder drops into mixing vessel, and mixing vessel rotation is evenly mixed.Now, by mixing vessel is made to drum, it is along the circumferential direction rotated, can make it successfully mix.By this operation, can prepare and contain HfO ₂the tungsten powder of particle.In addition, consider and when sintering circuit described later, carry out deoxidation, can also add micro-carbon dust.

Then, use the HfO that contains of gained ₂the tungsten powder of particle is prepared into body.When being formed into body, make as required the molding that uses tackiness agent.In addition when molding is cylindrical shape, be better that diameter is the cylindrical shape of 0.1～40mm.In addition,, situation about cutting out from tabular sintered compact as described later, the size of molding is arbitrarily.In addition, the length of molding (thickness) is arbitrarily.

Then, carry out the operation of presintering molding.Presintering is better to carry out at 1250～1500 ℃.By this operation, can access presintering body.Then, carry out presintering body to carry out the operation of resistance sintering.Resistance sintering is better with sintered compact, to reach the temperature condition of 2100～2500 ℃ to switch on.If temperature, less than 2100 ℃, cannot reach sufficient densification, strength decreased.In addition, if surpass 2500 ℃, HfO ₂the grain overgrowth of particle and tungsten particle, cannot obtain target crystal structure.

In addition, as additive method, can use molding sintering method of 1～20 hour at 1400～3000 ℃ of temperature.If sintering temperature is less than 1400 ℃ or sintering time less than 1 hour, sintering is insufficient, the strength degradation of sintered compact.In addition, if sintering temperature surpasses 3000 ℃ or sintering time, surpass 20 hours, tungsten crystallization excessively grain grow.

In addition,, as sintering atmosphere, can exemplify in the inert atmosphere of nitrogen or argon etc., in the reducing atmosphere of hydrogen etc., in vacuum.If these atmosphere, HfO when sintering circuit ₂the carbon of particle can decarburization.When decarburization, the impurity oxygen in tungsten powder is removed together, so the oxygen level in tungstenalloy can be reduced to below 1wt%, be further reduced to below 0.5wt%.If the oxygen level in tungstenalloy reduces, electroconductibility improves.

By this sintering circuit, can obtain the tungsten sintered compact that contains Hf composition.In addition,, if presintering body is cylindrical shape, sintered compact also can become cylindric sintered compact (ingot casting).In addition, be in the situation of tabular sintered body, cut into the operation of specified dimension.By this cutting action, form cylindric sintered compact (ingot casting).

Then,, by cylindric sintered compact (ingot casting) is implemented to forge processing, rolling processing, Wire Drawing etc., be prepared the operation of wire diameter.Working modulus is now 30～90% scope more fortunately.This working modulus refers to the sectional area of the cylindric sintered compact before processing is denoted as to A, when the sectional area of the cylindric sintered compact after processing is denoted as to B, according to working modulus=[(A-B)/A] * 100% value of calculating.In addition, the preparation of wire diameter is better to be undertaken by repeatedly processing.By repeatedly processing, the hole of the cylindric sintered compact before processing can be destroyed, obtain the electrod assembly that density is high.

For example, the situation that utilization is processed into the cylindric sintered compact of diameter 20mm by the cylindric sintered compact of diameter 25mm describes.The sectional area A of the circle of diameter 25mm is 460.6mm ², the sectional area B of the circle of diameter 20mm is 314mm ²so working modulus is 32%=[(460.6-314)/460.6] * 100%.Now, be better that Wire Drawing by repeatedly etc. is carried out the processing from diameter 25mm to diameter 20mm.

In addition, if working modulus is low, to less than 30%, crystal structure cannot fully extend on machine direction, and tungsten crystallization and thorium composition particle are difficult to reach the size of target.In addition, if working modulus is little of less than 30%, can not fully destroy the hole of the cylindric sintered compact inside before processing, likely former state ground is remaining.If remaining internal void, can become the reason that the weather resistance etc. of cathode assembly declines.On the other hand, if working modulus arrives and surpasses 90% greatly, because overprocessing likely breaks and decrease in yield.Therefore, working modulus is 30～90%, is better 35～70%.

In addition, after sintering completes, the relative density of the tungstenalloy of (Ga り on Japanese: Ware Knot), also can not necessarily be processed with the working modulus of regulation above in the situation that 95%.

In addition, wire diameter is machined to after 0.1～30mm, by cutting into the length needing, makes electrod assembly.In addition, as required, leading section is processed into cone-shaped.In addition, carry out as required attrition process, thermal treatment (recrystallization thermal treatment etc.), shape processing.

In addition, recrystallization thermal treatment is better that the scope with 1300～2500 ℃ is carried out in reducing atmosphere, inert atmosphere or vacuum.By recrystallization thermal treatment, can obtain the heat treated effect of rectification that relaxes the internal stress producing in being processed into the operation of electrod assembly, improve the intensity of parts.

According to manufacture method as above, can manufacture efficiently tungstenalloy and the electrode for discharge lamp parts of embodiment.

By the physical property of enumerating in specific the second embodiment in the tungstenalloy at the first embodiment, or the physical property of enumerating in specific the first embodiment in the tungstenalloy of the second embodiment, can expect the further raising of emission characteristic.For example, by the tungstenalloy at the first embodiment as the second embodiment to HfO ₂the primary particle size of particle and aggregate particle size, HfO ₂the dispersion state of dispersion of particles state, metal Hf, become HfO ₂the ratio, dispersion-strengthened material, relative density, Vickers' hardness of Hf in any carry out specificly, can improve emission characteristic.In addition, by the tungstenalloy parts at the first embodiment as the second embodiment the crystal structure of pair cross-section, surface roughness Ra carry out specificly, can improve emission characteristic.

Embodiment

(embodiment 1)

As raw material powder, in the tungsten powder (purity 99.99wt%) of median size 2 μ m, add the HfO of median size 2 μ m ₂powder (purity 99.0%) is so that it reaches 1.5wt%.In addition, at HfO ₂in powder, when Hf amount is denoted as to 100 mass parts, impurity Zr amount is 1.0 mass parts.

Raw material powder is mixed 10 hours with ball mill, made mixing raw material powder.Then, mixing raw material powder is dropped in mould, be made into body.To the molding of gained in hydrogen with 1800 ℃ of stove sintering that carry out 10 hours.By this operation, obtain the sintered compact of vertical 16mm * horizontal 16mm * long 420mm.

By forging, process etc., make the rod that cross section, footpath is square shape or toroidal, then cut out the cylindrical sample of diameter 2.4mm * long 150mm.For sample, implement centreless grinding processing, make surface roughness Ra below 5 μ m.Then,, as correcting thermal treatment, in hydrogen, implemented the thermal treatment of 1600 ℃.

By this, as the tungstenalloy parts of embodiment 1, make emission characteristic mensuration electrode, carried out transmitter current mensuration.

(comparative example 1)

Made by the ThO that contains 2wt% ₂the unidimensional use for discharge lamp cathode assembly that forms of tungstenalloy.

About the tungstenalloy parts of embodiment 1, investigated HfO ₂content (the HfO of composition ₂conversion amount), the content of Hf and O is converted into HfO _xtime the carbon amount of x value, surface element and central part, the median size of tungsten crystallization.HfO ₂the quantitative analysis that contains of composition is analyzed Hf amount, oxygen amount by icp analysis, rare gas element melting-infrared absorption, is scaled HfO _x.In addition, the carbon quantitative analysis of surface element and central part is that the scope from surperficial 10 μ m cuts to measure and cuts mensuration sample with sample and from cylindrical cross-section, by burning-infrared absorption, measures respectively carbon amount.In addition, the average crystallite particle diameter of tungsten is measuring 100 in section structure arbitrarily, using its mean value as average crystallite particle diameter.The results are shown in table 1.

[table 1]

Then, investigated the emission characteristic of the use for discharge lamp cathode assembly of embodiment 1 and comparative example 1.The mensuration of emission characteristic is to make to apply voltage (V) to change into 100V, 200V, 300V, 400V, measures emission (mA/mm ²).The current load applying at anticathode parts is to measure under 18 ± 0.5A/W, the application time condition that is 20ms.The results are shown in Figure 10.

Known according to Figure 10, embodiment 1 compares with comparative example 1, and emission characteristic is excellent.From this result, the use for discharge lamp cathode assembly of embodiment 1 is not used as the Thorotrast of radioactive substance, demonstrates excellent emission characteristic yet.In addition, cathode assembly has reached 2100～2200 ℃ during mensuration.The hot strength of the cathode assembly of hence one can see that embodiment 1 and life-span etc. are also excellent.

(embodiment 2～6)

Then, prepared the HfO that changed as shown in table 2 ₂addition, HfC addition, as the raw material mixed powder of the K addition of dopant material.Each raw material mixed powder is carried out to die forming, in hydrogen, with 1500～1900 ℃ of sintering 7～16 hours, obtain sintered compact.In addition, in embodiment 2～3, make sintered compact size similarly to Example 1, carried out cutting action.In addition, in embodiment 4～5, be modulated into feature dimension, directly obtain the sintered compact of diameter 2.4mm * long 150mm.In embodiment 6, added the HfC powder (purity 99.0%) of the median size 2 μ m of 0.5wt%.In addition, at HfO ₂in powder, when Hf amount is denoted as to 100 mass parts, impurity Zr amount is 1.0 mass parts.In addition use, the HfO of embodiment 6 ₂in the situation of powder and HfC powder, when Hf amount is denoted as to 100 mass parts, impurity Zr amount is 1.0 mass parts.

For each sample, implement centreless grinding processing, make surface roughness Ra below 5 μ m.Then leading section is processed into cross section and is the triangular shape of 45 °.Then,, as correcting thermal treatment, in hydrogen, implemented the thermal treatment of 1400 ℃～1700 ℃.By this, make the use for discharge lamp cathode assembly of embodiment 2～5, carried out mensuration similarly to Example 1.The results are shown in table 3.

[table 2]

?	HfO2 addition	K addition	HfC addition
				Embodiment 2	0.5	Nothing	Nothing
Embodiment 3	1.0	Nothing	Nothing
				Embodiment 4	2.3	0.005	Nothing
Embodiment 5	1.2	Nothing	Nothing
				Embodiment 6	1.0	Nothing	O.5

[table 3]

Then, under condition similarly to Example 1, evaluated emission characteristic.The results are shown in table 4.

[table 4]

Known according to table, any in the use for discharge lamp cathode assembly of the present embodiment all demonstrated excellent characteristic.In addition, cathode assembly has reached 2100～2200 ℃ during mensuration.The hot strength of the cathode assembly of hence one can see that embodiment 2～6 and life-span etc. are also excellent.In embodiment 1～5, contain Hf and HfO ₂these two kinds.In addition, in embodiment 6, contain Hf, HfO ₂with these three kinds of HfC.

(embodiment 11～20, comparative example 11)

As raw material powder, the tungsten powder shown in table 5 (more than purity 99.0wt%), HfO have been prepared ₂powder.Each powder is fully disassembled with ball mill, and the operation of sieving is as required so that maximum diameter separately reaches the value shown in table 5.

[table 5]

Then, by the Hf composition in tungstenalloy with HfO ₂convert and count, make tungsten powder and HfO ₂powder mixes to reach the condition of the ratio shown in table 6, utilizes ball mill again to mix.Then form, prepared molding.Then with the condition shown in table 6, carried out sintering circuit.Obtain the sintered compact of vertical 16mm * horizontal 16mm * long 420mm.

[table 6]

Then, from the tungstenalloy sintered compact of gained, cut out cylindric sintered compact (ingot casting), by forging processing, rolling processing, the appropriately combined wire diameter of adjusting of Wire Drawing.Working modulus is as shown in table 7.In addition, adjust after wire diameter, cut out the length of regulation, leading section is processed into cone-shaped.Then, carry out surface grinding, be ground to surface roughness Ra below 5 μ m.Then, in nitrogen atmosphere, implemented the recrystallization thermal treatment of 1600 ℃.By this, electrode for discharge lamp parts have been completed.

[table 7]

Then, take the circumferential direction cross section of main part and the enlarged photograph in side surface direction cross section of each electrode for discharge lamp parts, measured HfO ₂the ratio of the maximum diameter of the median size of the primary particle of composition, primary particle and offspring, tungsten crystalline particle, median size, long-width ratio.About enlarged photograph, cut out respectively by circumferential section and the side surface direction cross section at the center of main part, unit surface 300 μ m * 300 μ m are arbitrarily investigated.The results are shown in table 8.

[table 8]

Then,, for each electrode for discharge lamp parts, measured the content of Hf and O has been scaled to HfO _xtime x value, the HfO in Hf composition ₂ratio.In addition, calculate oxygen level, relative density (%), Vickers' hardness (Hv), 3 flexural strengths.

About the HfO in Hf composition ₂ratio, the Hf measuring in tungstenalloy by icp analysis method measures, by the carbon amount in burning-infrared absorption mensuration tungstenalloy.Can think that the carbon in tungstenalloy becomes HfO ₂.Therefore, detected total Hf amount is denoted as to 100 weight parts, converts and form HfO ₂hf amount, obtain its mass ratio.In addition, the oxygen level in tungstenalloy is analyzed by burn-infrared absorption of rare gas element.In addition, relative density is by calculating the actual density that analysis obtains according to Archimedes's method divided by theoretical density.In addition, theoretical density is tried to achieve by aforesaid calculating.In addition, Vickers' hardness (Hv) is tried to achieve according to JIS-Z-2244.In addition, 3 flexural strengths are tried to achieve according to JIS-R-1601.The results are shown in table 9.

[table 9]

The density of the electrode for discharge lamp parts of the present embodiment is high, and Vickers' hardness (Hv) also demonstrates excellent value.This is because HfO ₂a part there is deoxidation.In addition, do not form HfO ₂hf composition in following any state: formed metal Hf particle; HfO ₂a surperficial part for particle has formed metal Hf; Formed the sosoloid of tungsten and hafnium.That is,, as Hf composition, contain Hf and HfO ₂these two kinds.

(embodiment 21～25)

Then, as tungsten powder and HfO ₂powder is used powder similarly to Example 12, and the composition of preparing to change composition shown in table 10 into is as the second composition.Sintering condition is made as in nitrogen atmosphere, carry out stove sintering with 2000 ℃, obtains ingot casting.Ingot casting is processed with working modulus 50%, obtained the electrod assembly of wire diameter 10mm.In addition in nitrogen atmosphere, implemented, the recrystallization thermal treatment of 1600 ℃.Each embodiment has been carried out to same mensuration.The results are shown in table 10～12.

[table 10]

[table 11]

[table 12]

According to table, can find, by use, add element, dispersion-strengthened function is strengthened, and the grain of tungsten crystallization is grown up and is inhibited, so intensity improves.

(embodiment 11A～25A, comparative example 11-1A～11-2A and comparative example 12A)

Investigated the emission characteristic of the electrode for discharge lamp parts of embodiment 11A～25A, comparative example 11-1A and comparative example 11-2A.The mensuration of emission characteristic is to make to apply voltage (V) to change into 100V, 200V, 300V, 400V, measures emission (mA/mm ²).At the current load that electrode for discharge lamp parts are applied, be to measure under 18 ± 0.5A/W, the application time condition that is 20ms.

In addition, 12A, has made by the ThO that contains 2wt% as a comparative example ₂the electrode for discharge lamp parts of the wire diameter 8mm that forms of tungstenalloy.The results are shown in table 13.

[table 13]

Although the electrode for discharge lamp parts of each embodiment are not used Thorotrast, still demonstrate emission characteristic identical with the comparative example 12 that uses Thorotrast or more than it.In addition, electrod assembly has reached 2100～2200 ℃ during mensuration.So the hot strength of the electrode for discharge lamp parts of each embodiment is also excellent.

(embodiment 26～28)

Then, electrode for discharge lamp parts for embodiment 11, embodiment 13, embodiment 18, except recrystallization heat-treat condition is changed into 1800 ℃, by identical manufacture method, manufacture, as embodiment 26, (the recrystallization heat-treat condition of embodiment 11 is changed to the electrode for discharge lamp parts of manufacturing into 1800 ℃), embodiment 27 (changing the recrystallization heat-treat condition of embodiment 13 into 1800 ℃), embodiment 28 (changing the recrystallization heat-treat condition of embodiment 18 into 1800 ℃) and prepare.Carried out same mensuration.The results are shown in table 14～15.

[table 14]

[table 15]

The density of the electrode for discharge lamp parts of the present embodiment is high, and Vickers' hardness (Hv) and 3 flexural strengths also demonstrate excellent value.This is because HfO ₂a part there is deoxidation.In addition, to not forming HfO ₂hf composition analyze, result is the sosoloid that has all formed tungsten and hafnium.That is,, as Hf composition, there is Hf and HfO ₂these two kinds.Therefore, if known, make recrystallization thermal treatment temp reach more than 1700 ℃, easily make metal Hf solid solution in tungsten.In addition, by the same method of the situation with table 13, measured emission characteristic.

[table 16]

As mentioned above, known by making the whole solid solutions of metal Hf in tungsten, can improve emission characteristic.Can think that its reason is: by solid solution, metal Hf is easily present in the surface of tungstenalloy.

In addition as mentioned above, because emission characteristic is excellent, so be not limited to electrode for discharge lamp parts, also can use in the field of requiring the parts for magnetron (coil component) of emission characteristic, for transmitting tube parts (mesh grid) etc..

The explanation of symbol

1 ... cathode electrode, 2 ... electrode body portion, 3 ... electrode leading section, 4 ... discharge lamp, 5 ... electrode support rod, 6 ... Glass tubing, 7 ... coil component, 8 ... upper support parts, 9 ... lower support parts, 10 ... support rod, 11 ... magnetron cathode structure body, 21 ... electrode for discharge lamp parts, 22 ... the electrode for discharge lamp parts with the leading section of cone-shaped, 23 ... leading section, 24 ... main part, 25 ... circumferential direction cross section, 26 ... side surface direction cross section, 27 ... discharge lamp, 28 ... electrode support rod, 29 ... Glass tubing.

Claims

1. a tungstenalloy, it is to contain W composition and be selected from Hf, HfO ₂, HfC and C the tungstenalloy of at least two or more compositions, it is characterized in that, Hf composition is with HfO ₂in the scope of meter below the above 3wt% of 0.1wt% that convert.

2. a tungstenalloy, it is contain W composition and comprise HfO ₂the tungstenalloy of the Hf composition of particle, is characterized in that, described Hf composition is with HfO ₂in the scope of meter below the above 5wt% of 0.1wt% that convert, described HfO ₂the average primary particle diameter of particle is below 15 μ m.

3. tungstenalloy as claimed in claim 2, is characterized in that, described HfO ₂the median size of the primary particle size of particle is below 5 μ m, and maximum diameter is below 15 μ m.

4. tungstenalloy as claimed in claim 2 or claim 3, is characterized in that described HfO ₂the maximum value of the aggregate particle size of particle is below 100 μ m.

5. the tungstenalloy as described in any one in claim 1～4, is characterized in that, by the content of Hf and O with HfO _xduring conversion, x < 2.

6. the tungstenalloy as described in any one in claim 1～4, is characterized in that, by the content of Hf and O with HfO _xduring conversion, 0 < x < 2.

7. the tungstenalloy as described in any one in claim 1～6, is characterized in that, contains below at least one element that is selected from K, Si and Al with 0.01wt%.

8. the tungstenalloy as described in any one in claim 1～7, is characterized in that, when Hf content is denoted as to 100 mass parts, Zr content is below 10 mass parts.

9. the tungstenalloy as described in any one in claim 1～8, is characterized in that, described Hf composition contains the metal Hf of solid solution in W.

10. the tungstenalloy as described in any one in claim 1～9, is characterized in that, described Hf composition contains metal Hf, and described metal Hf is present in surface.

11. tungstenalloys as described in any one in claim 1～10, is characterized in that, when Hf content is denoted as to 100 mass parts, become HfO ₂the ratio of the Hf of particle is below above 98 mass parts of 30 mass parts.

12. tungstenalloys as described in any one in claim 1～11, is characterized in that, Vickers' hardness Hv is more than 330.

13. tungstenalloys as described in any one in claim 1～12, is characterized in that, described W composition comprises average crystallite particle diameter of the tungsten particle below 100 μ m more than 1 μ m.

14. 1 kinds of tungstenalloy parts, is characterized in that, comprise the tungstenalloy described in any one in claim 1～13.

15. 1 kinds of tungstenalloy parts, is characterized in that, comprise the tungstenalloy described in any one in claim 1～13, and are that wire diameter is the wire rod below the above 30mm of 0.1mm.

16. tungstenalloy parts as claimed in claim 15, is characterized in that, the crystal structure of the cross section of described wire rod is: in per unit area 300 μ m * 300 μ m, crystallization particle diameter is that the shared area occupation ratio of the tungsten crystallization below the above 80 μ m of 1 μ m is more than 90%.

17. tungstenalloy parts as claimed in claim 15, it is characterized in that, the crystal structure of the vertical section of described wire rod is: in per unit area 300 μ m * 300 μ m, crystallization particle diameter is that the shared area occupation ratio of the tungsten crystallization below the above 120 μ m of 2 μ m is more than 90%.

18. tungstenalloy parts as described in any one in claim 14～17, is characterized in that, these tungstenalloy parts be used to be selected from use for discharge lamp parts, transmitting tube with parts and magnetron at least one parts with parts.

19. 1 kinds of discharge lamps, is characterized in that, possess the tungstenalloy parts described in any one in claim 14～18.

20. 1 kinds of transmitting tubes, is characterized in that, possess the tungstenalloy parts described in any one in claim 14～18.

21. 1 kinds of magnetrons, is characterized in that, possess the tungstenalloy parts described in any one in claim 14～18.