CN1034185C - High firmness hydrogen absorption and its isotope getter - Google Patents

Abstract

The present invention relates to a high-firmness selecting hydrogen absorbing material which is composed of zirconium, zirconium intermetallic compounds and anti sintering elementals, wherein the zirconium intermetallic compounds are zirconium ZrAl16, and the anti sintering elements are silicon or graphite. The present invention is composed of components of the following proportion by weight: 5-to 40% of the zirconium intermetallic compounds, 1 to 10% of the anti sintering elements and the rest is zirconium. The present invention has the advantages of excellent gas suction performance and higher degree of fastness.

Description

High firmness is inhaled hydrogen and isotropic substance getter thereof

The application is that invention and created name is dividing an application of " high firmness being inhaled hydrogen and isotropic substance getter thereof ", and the applying date of original application is on December 29th, 1992, application number 92114945.X.

The invention belongs to getter material, especially relevant with the selection hydrogen-absorbing material of high firmness.

Getter is mainly used in various electron tubes, to improve and to keep the vacuum tightness in the device, the work-ing life of prolongation device; Also can be used in the aeration vessel, to improve the purity of gas, have and select the getter material of gettering ability also to have special application,, getter is proposed new requirement along with science and technology development, not only require it that good pumping property is arranged, wish that also getter after inhaling hydrogen hydrogen embrittlement does not take place, and have high firmness, device is worked under ultra-high voltage or judder condition do not have μ m level dry linting, yet existing getter does not reach these requirements

The objective of the invention is to design a kind of have high firmness, inhale hydrogen and the good getter of isotropic substance performance thereof,

High firmness getter of the present invention is elementary composition by zirconium, zirconium intermetallic compound and anti-sintering, and the zirconium intermetallic compound is zirconium Al intermetallic ZrAl ₁₆, anti-sintering element is silicon or graphite, it consists of the intermetallic compound 5-40% (weight percentage, down with) of zirconium, anti-sintering element be 1-10%, all the other be zirconium,

Air-breathing its gettering rate of nonevaporable getter depends on dominant bulk diffusion or brilliant Jie's diffusion under the high temperature, and the main abutment surface of using at a lower temperature of nonevaporable getter plays getter action, have only the surface reaction of promotion could effectively improve its gettering rate, the most effective way is the porosity that increases material itself under the prerequisite that does not change getter physical dimension, promptly improve the specific surface area of getter, but this method certainly will make the compactness variation of material, it is the intensity variation, in order to make material keep good pumping property, have high intensity and firmness again concurrently, the present invention has adopted new technical scheme, the intermetallic compound and the anti-sintering element that promptly in the active element zirconium, add zirconium simultaneously

The intermetallic compound that adds zirconium among the present invention is both as the bonding phase, also be in order to improve its hydrogen sucking function, the intermetallic compound of zirconium has zirconium aluminium, ferrozirconium, zirconium nickel, the diffusion activation energy of gas in zirconium alloy is much smaller than pure zirconium, for example the diffusion activation energy of hydrogen in zirconium alloy is 8792.3 Jiao Er/mol, and the diffusion activation energy in pure zirconium is 46892.2 Jiao Er/mol, in other intermetallic compounds of zirconium similar characteristics is arranged also, Fig. 1 is disclosed zirconium aluminium (ZrAl in GB2047950 ₁₆) zirconium nickel (Zr ₂Ni) and ferrozirconium (Zr ₂Fe) the hydrogen absorption characteristic curve of intermetallic compound under 400 ℃ of conditions illustrates that these three kinds of intermetallic compounds all are good hydrogen-absorbing materials, joins the hydrogen sucking function that removes can help improving alloy material in the active element zirconium in right amount,

Add bonding in the getter and be mutually for make obtain between the active element particle certain moistening and bonding arranged slightly on the surface, but do not wish the mutual sintering of active element, otherwise can make it lose getter action, for the sintering of avoiding active element and prevent active element when the sintering gathering and grow up, and suppress the obvious contraction of sintered powder, must add an amount of anti-sintering element, commonly used anti-sintering unit have graphite, silicon etc., especially to add anti-sintering element graphite 1-5% for well

The getter of the present invention's design has following advantage,

1. pumping property is good, and good hydrogen sucking function is especially arranged

Begin to inhale the tenth minute gettering rate of hydrogen after the activation greater than 10 cubes of meter per seconds

Square metre,

2. operating temperature range is wide

But equal works better in-45 ℃～55 ℃ temperature ranges,

Hydrogen reach 13.3 cubic metres of handkerchiefs/square metre after hydrogen embrittlement does not take place,

4. firmness height,

Fig. 1 is the hydrogen absorption characteristic curves of several compounds under 400 ℃ of conditions, and ordinate is a gettering rate, and abscissa is a gulp capacity, wherein 1 represents ZrAl ₁₆, 2 represent Zr ₂Ni, 3 represent Zr ₂Fe,

Fig. 2 is the synoptic diagram of firmness determinator,

Below in conjunction with embodiment the embodiment and the advantage of getter of the present invention are further described,

One, uses atomic level zirconium, zirconium powder, fine aluminium; the spectroscopically pure graphite powder is a raw material; after pressing zirconium 84, aluminium 16 weight percents batching with zirconium sponge and fine aluminium; system zirconium aluminium ingot under the non-consumable arc furnace argon shield; obtain the zirconium aluminium powder after fragmentation, screening, the X-ray Phase Structure Analysis shows that this zirconium aluminium powder is ZrAl ₁₆Intermetallic compound will be pressed the proportion ingredient in the table 1 less than 46 microns this intermetallic compound powder, zirconium powder, Graphite Powder 99 respectively after 75 ± 5 ℃ of bakings under the vacuum, behind thorough mixing, add fir balsam as binding agent, after the compression moulding, earlier at 650 ℃, vacuum tightness is 1.33 * 10 ^-2Low temperature gave sintering 10 minutes under the handkerchief, and respectively 930 ℃, 1050 ℃ differing tempss, vacuum tightness is 1.33 * 10 again ^-8High temperature sintering is 10 minutes under the handkerchief, promptly makes the getter of a kind of composition of the present invention's design, and its relevant performance is listed in the table 1,

Use zirconium powder and Graphite Powder 99 to adopt common process to make the Zr-C getter of prior art.

The sample that makes is carried out the mensuration of pumping property, firmness respectively, and wherein pumping property is undertaken by national Specification, adopts to be of a size of Φ _Outward11.5 * Φ _In6.3 * 1.5 millimeters ring-type sample, the getter exposed area is 0.62 square centimeter, the measuring method of firmness adopts the destructive test method, the synoptic diagram of firmness determinator is seen Fig. 2, this device is by vibrating device 1, shaking platform 2, be arranged on metal vessel 3 and compositions such as cover plate 4 and thrust screw 5 on the platform, the end of metal vessel is a wire netting 6, the centre has dividing plate 7 that container is separated into some spaces, sample to be tested is placed in each space, the frequency of vibrating device and amplitude range can be regulated as required, after on-test, sample is done random motion, sample and wall of container in the vibration of container internal cause, cover plate, dividing plate and bottom metal net collide, increasing along with the test frequency amplitude, it is fierce more to clash into, and time of vibration is long more, and the sample wearing and tearing are serious more.For reduce error as far as possible, need the correlated sample of identical conditions can be contained in the different spaces of same container respectively, adopt the comparability of testing with raising with the method for condition vibration on the same stage, after the off-test, take out respectively and weigh, be calculated as follows the sample rate of weight loss then, rate of weight loss size per sample, judge the firmness of material, the more little illustrative material firmness of rate of weight loss is big more $\mathrm{\ΔW}=\frac{A-B}{A}\×100\%$ △ W-sample rate of weight loss (%) in the formula,

Example weight (gram) before the A-vibration,

B-vibration back example weight (gram),

Test sample is the cylinder of 6 * 5 millimeters of φ, and vibrational frequency 38Hz, amplitude are 1.2 millimeters, and time of vibration 40 minutes is weighed on ten thousand/balance,

The pumping property that records, firmness (percentage loss of weight △ W) the results are shown in Table 1,

S10 begins air-breathing the 10th minute gettering rate after material activates, unit cube meter per second square metre,

Q30 begins air-breathing back the 30th minute accumulative total inspiratory capacity after material activates, unit cubic meter handkerchief/square metre,

As can be seen from Table 1, material percentage loss of weight of the present invention is little, and illustrative material intensity improves, and its rate of weight loss is that the strength of materials improves than having extremely significantly of Zr-C,

Table 1

Ratio of components (weight %)			Inhale the H2 performance		Inhale the CO performance		Inhale the N2 performance		Percentage loss of weight △ W%
										Zirconium	Zirconium aluminium	Graphite	S10	Q30	S10	Q30	S10	Q30
94	5	1	11.2	2.64	3.03	2.79	2.68	1.88											0.28
									90	8	2	11.6	2.81	3.15	2.83	2.71	1.90	0.32
87	10	3	12.0	2.94	3.27	2.91	2.82	1.98											0.69
									80	18	4	13.1	3.01	3.36	3.11	2.95	2.02	0.69
70	25	5	15.3	3.15	3.81	3.23	3.10	2.23											0.71
									65	30	5	15.8	3.21	3.98	3.35	3.25	2.30	0.70
Zr-c			11.2	2.86	2.40	0.78	2.17	0.65											3.74

Claims (2)

1. one kind high firmness getter is characterized in that, said getter is elementary composition by zirconium, zirconium intermetallic compound and anti-sintering, and said zirconium intermetallic compound is zirconium Al intermetallic ZrAl ₁₆, said anti-sintering element is silicon or graphite, and it consists of zirconium intermetallic compound 5-40% (weight percentage, down together), and anti-sintering element is 1-10%, and all the other are zirconium,

2. according to the said high firmness getter of claim 1, it is characterized in that anti-sintering element graphite is 1-5%,

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