Title of Invention

NON-EVAPORATABLE GETTER ALLOYS AND GETTER DEVICES

Abstract Non-evaporable getter alloys zirconium, vanadium, iron, manganese and one or more elements selected among yttrium, lanthanum and Rare Earths are described having improved features of gas sorption, particularly of nitrogen, with respect to the known getter alloys.
Full Text NON-EVAPORABLE GETTER ALLOYS AND GETTER DEVICES
The present invention relates to non-evaporable getter alloys and
getter devices. '
Particularly, the invention relates to non-evaporable getter alloys which
provide for a high efficiency in the sorption of gases, particularly of nitrogen.
Non-evaporable getter alloys, also known as NgG alloys, can sorb hydrogen
in a reversible way and gases such as oxygen, water, carbon oxides and, in the
case of some alloys, nitrogen, irreversibly;,
A first use of these alloys is vacuum maintenance. Vacuum maintenance is
requested in the most various applications, for example in particles accelerators,
in X-rays generator tubes, in flat displays of the field emission type and in
thermally insulating evacuated interspaces, such as in thermal bottles (thermos), in
Dewars or in the pipings for oil extraction and transportation.
The NEG alloys can also be used for removing the above mentioned gases
when they are present in traces inside other gases, generally noble gases. An
example is the use in lamps, particularly the fluorescent ones which are filled with
noble gases at pressures of a few tens of millibars, wherein the NEG alloy has the
purpose of removing traces of oxygen, water, hydrogen and other gases, thus
maintaining the suitable atmosphere for the lamp functioning; another example of
removal of traces of the cited gases from other gases is the purification of inert
gases, in particular for applications in microelectronic industry.
Generally these alloys have zirconium and/or titanium as main components
and comprise one or more elements selected among transition metals or
aluminum.
NEG alloys are the subject matter of several patents. Patent US 3,203,901
discloses Zr-Al alloys, and in particular the alloy having weight percent
composition Zr 84% - Al 16%, manufactured and sold by the applicant under the
name St 101; patent US 4,071,335 discloses Zr-Ni alloys, and in particular the
alloy having weight composition Zr 75.7% - Ni 24.3%, manufactured and sold by
the applicant under the name St 199; patent US 4,306,887 discloses Zr-Fe alloys,
and particularly the alloy having weight percent composition Zr 76.6% - Fe
23.4%, produced and sold by the applicant under the name St 198; patent US
4,312,669 discloses Zr-V-Fe alloys, and in particular the alloy having weight
composition Zr 70% - V 24.6% - Fe 5.4%, manufactured and sold by the applicant
under the name St 707; patent US 4,668,424 discloses zirconium-nickel-
mischmetal alloys, with optional addition of one or more transition metals; patent
US 4,839,085 discloses Zr-V-E alloys, wherein E is an element selected among
iron, nickel, manganese and aluminum or a mixture thereof; patent US 5,180,568
discloses intermetallic compounds ZrjM'iM"!, wherein M' and M", either alike or
different, are selected among Cr, Mn, Fe, Co and Ni, and in particular the
compound ZriMniFei manufactured and sold by the applicant under the name St
909; patent US 5,961,750 discloses Zr-Co-A alloys, wherein A is an element
selected among yttrium, lanthanum, Rare Earths or a mixture thereof, and
particularly the alloy having weight composition Zr 80.8%-Co 14.2%-A 5%,
produced and sold by the applicant under the name St 787; finally, getter alloys
based on Zr and V for use in gas purifiers are described in various patent
applications published in the name of the firm Japan Pionics, among which for
example the applications Kokai 5-4809, 6-135707 and 7-242401.
NEG alloys have different properties according to their composition. For
example, the alloy St 101 is, among those mentioned, the best one as long as
hydrogen sorption is concerned, but requires, for working, an activation treatment
at relatively high temperatures, of at least 700°C; the alloy St 198 has poor
nitrogen sorption properties, therefore it is employed for the purification of this
gas; the compounds described in patent US 5,180,568 do not sorb hydrogen. As a
result of these behavior differences, the choice of the NEG alloy to be employed
depends on the specific foreseen application. In particular, it may be stated that,
among these, the most largely used is the one named St 707, as described in patent
US 4,312,669, thanks to its good sorption qualities, in particular for hydrogen, and
to the relatively low activation temperature required by this NEG alloy.
Removal of atmospheric gases is important in some applications. This is for
example the case of the thermal insulation, wherein the gases which remain in the
evacuated interspace during the manufacture have to be removed: as a matter of
fact, in order to maintain the production costs within acceptable limits, the
pumping of the interspace which is carried out before the sealing thereof is
generally interrupted after a fixed time, generally leaving a residual pressure,
although limited, in the interspace itself. The sorption of the atmospheric gases is
also requested in the currently studied application of the energy inertial
accumulators, better known with the definition "fly wheels", which work on the
principle of rotating an object of high mass at high speed in an evacuated
chamber; vacuum is necessary in this application in order to prevent the rotating
mass from losing energy because of the friction with the gases present in the
chamber. In these applications, particularly important for the choice of the NEG
alloys is the behavior towards nitrogen, both because this gas forms about 80% of
the composition of the atmosphere, and because it is the one, among atmospheric
gases (with the exception of the noble gases), which is removed by the NEG with
the highest difficulty.
The industrial application which currently requires the highest efficiency of
undesired gases removal is purification of gases for the semiconductor industry.
As a matter of fact, it is known that impurities in the process gases can be
incorporated into the layers which form the solid state devices, thus causing
electronic defects in them and therefore production rejects. The degrees of purity
which are presently requested by the semiconductor industry are of the order of
the ppt (10"12 in atoms or molecules). Therefore, the availability of NEG alloys
having very high efficiency of impurity sorption is necessary; as above noted,
nitrogen is, among gases which represent the normal impurities in a process gas,
the one which is removed with the highest difficulty from the NEG alloys.
Object of the present invention is therefore providing non-evaporable getter
alloys having high gas sorption efficiency, particularly nitrogen.^
Accordingly, the present invention provides a non-evaporable
getter alloys having high gas sorption efficiency, particularly for nitrogen,
comprising zirconium, vanadium, iron, manganese and at least one element
selected from yttrium, lanthanum and Rare Earths, having a weight percent
composition of the elements which can vary within the following ranges :
- zirconium from 60 to 85% ;
- vanadium from 2 to 20% ;
- iron from 0.5 to 10% ;
- manganese from 2.5 to 30% ;
- yttrium, lanthanum and Rare Earths or mixtures thereof from 1 to
6%.
The present invention also provides getter devices formed of, or
comprising, powders of non-evaporable getter alloys comprising zirconium,
vanadium, iron, manganese and at least one element selected among
yttrium, lanthanum and Rare Earths, said alloys having a weight percent
composition of the elements which can vary within the following ranges :
- zirconium from 60 to 85% ;
- vanadium from 2 to 20% ;
- iron from 0.5 to 10% ;
- manganese from 2.5 to 30% ;
- yttrium, lanthanum and Rare Earths or mixtures thereof from 1 to
6%.
This object is obtained according to the present invention by non-
evaporable getter alloys comprising zirconium, vanadium, iron, manganese
and at least one element selected from yttrium, lanthanum and Rare Earths,
having a percent composition of the elements variable within the following
ranges (in the rest of the text, all percentages and ratios are by weight, unless
otherwise specified) :
- zirconium from 60 to 85%;
- vanadium from 2 to 20%; v
-iron from 0.5 to 10%;
- manganese from 2.5 to 30%; and
- yttrium, lanthanum, Rare Earths or mixtures thereof from 1 to 6%.
The invention will be described in the following with reference to the
drawings, wherein:
- Figures 1 to 5 show various different embodiments of getter devices using
the alloys of the invention;
- Figures 6 to 11 show the results of gas sorption tests under various
conditions by the alloys of the invention and a reference alloy. •¦
The alloy according to the invention differ from the alloys known from
patent US 4,312,669 because of the lower content of vanadium and iron, which
are replaced by manganese and one element among yttrium, lanthanum and Rare
Earths; from the alloys of patent US 4,668,424 because these do not involve the
use of vanadium and of manganese, and require instead the presence of nickel in
quantities between 20 and 45% by weight; from the alloys of patent US 4,839,085
because these do not require the use of yttrium, lanthanum or Rare Earths and
contain generally, with respect to the alloys of the invention, higher quantities of
vanadium and lower quantities of iron and manganese; from the compounds of
patent US 5,180,568, because these are ternary intermetallic coinpounds
ZriM'iM"i which do not contain vanadium or yttrium, lanthanum and Rare
Earths; and from the alloys of patent US 5,961,750 which require the presence of
cobalt and do not require the presence of vanadium, iron and manganese. As
above mentioned and widely described in the following, these differences in the
composition result in notable differences in the gas sorption, particularly as far as
nitrogen is concerned.
With zirconium contents lower than 60%, the performances of gas sorption
of the alloys of the invention decrease, whereas contents of this element higher
than 85% cause the alloys to be too plastic and difficult to work in the production
of getter devices. The contents of other components of the alloys which are
outside the indicated percentages generally involve reductions of the gas sorption
features, particularly of nitrogen in the case of high vanadium contents and of
hydrogen for high iron or manganese contents. Further, it has been found that
alloys containing vanadium less than 2% are too pyrophoric and therefore
dangerous to be produced and handled. Finally, percentages higher than 6% of
yttrium, lanthanum, Rare Earths or mixtures thereof do not improve the sorption
features of the alloys, but cause them to be unstable in the air with resulting
problems of storage before use. Particularly convenient for the invention is the
use, instead of the last mentioned elements, of mischmetal (also indicated simply
MM in the following). Various commercial mixtures are identified with this
name, comprising above all cerium, lanthanum and neodymium, and minor
quantities of other Rare Earths, of lower costs with respect to the pure elements.
The exact composition of the mischmetal is not important, because the above
mentioned elements have similar reactivities, so that the chemical behavior of the
different available types of mischmetals is essentially constant even if the content
of the single elements is varied, so that the exact composition of this component
does not have an influence over the working features of the alloys according to the
invention.
Within the indicated ranges, are preferred the alloys having a content of:
- zirconium varying between about 65 and 75%, and, even more preferably
between about 67 and 70%;
- vanadium 2.5 to 15%;
- manganese 5 to 25%;
- iron/vanadium ratio comprised between 1:4 and 1:5.
Particularly preferred among the alloys of the invention are an alloy having
composition Zr 70% - V 15% - Fe 3.3% - Mia 8.7% - MM 3% and an alloy of
composition Zr 69% - V 2,6% - Fe 0.6% - Mn 24.8% - MM 3%.
The alloys of the invention can be prepared by fusion in an oven starting
from pieces or powders of the component metals, taken in proportions
corresponding to the final desired composition. The techniques of fusion in an arc
oven under an inert gas atmosphere, for instance under a pressure of 300 mbars of
argon; or in an induction oven, under vacuum or an inert gas are preferred. It is
anyway possible the use of other techniques for the preparation of alloys which
are usual of the metallurgical industry.
In practical applications, the alloys of the invention are used in the form of
pellets of the getter material alone or on a support or inside a container. In any
case, the use of alloys in the form of powders having particle size generally lower
than 250 \im and preferably between 125 and 40 urn is preferred. With larger
particle size an excessive reduction of the specific surface of the material (surface
area per weight unit) takes place, whereas particle size values lower than 40 jam,
although can be used and requested for some applications, cause some problems
in the production steps of the getter devices (thin powders are more difficult to be
moved by automitized means and are more pyrophoric with respect to powders
having larger particle size).
The NEG alloys of the invention can be activated at temperatures comprised
between 300 and 500°C for periods between 10 minutes and 2 hours. The effect of
the temperature prevails over the treatment time, and an activation at 400°C for 10
minutes allows to obtain a nearly complete activation.
Once activated, these alloys are able to work for the sorption of gases such
as hydrogen, carbon oxide, and above all nitrogen, already at the room
temperature, with properties similar to the known alloys for hydrogen and better
ones for carbon oxide and nitrogen. Generally the maximum temperature of use is
about 500°C, not to compromise the stability and functionality of the device
wherein they are inserted. The optimal working temperatures of these alloys
depend on the specific applications; for instance, in the case of the interspaces for
thermal insulation the temperature is determined by that of the warmest wall of
the insterspace itself, in the case of the "fly wheels" the temperature is the room
temperature and in the purification of gases the temperature is generally between
about 300 and 400°C.
In the case of hydrogen, as for all known NEG materials, the soiption is
reversible so that the sorption features are evaluated in terms of equilibrium
hydrogen pressure on the alloy as a function of the temperature and of the quantity
of sorbed hydrogen. From this point of view the sorption of hydrogen by the
alloys of the invention is very good, and similar to that of the mentioned alloy St
707, that is the most widely used getter alloy. The alloy of the invention also have
at room temperature, with respect to the alloy St 707 in the same conditions,
sorption capacity up to 15 times greater for nitrogen and up to 10 times greater for
CO.
As already mentioned, the forms of the getter devices which can be prepared
by using the alloys of the invention are the most various, comprising for example
pellets formed only of powders of the getter alloy, or of these on a support,
generally metallic. In both cases the consolidation of the powders can be carried
out by compression or by compression followed by sintering. The pellets made
only of compressed powders find an application for example in thermal insulation
and in gas purifications. In the cases wherein the powders are supported, steel,
nickel or nickel alloys can be used as support material. The support can be simply
in the form of a band on the surface of which the powders of the alloy are adhered
by cold rolling or by sintering after deposition by various techniques. Getter
devices obtained from similar bands can be used in lamps. The support can also
be formed of a proper container having various shapes, wherein the powders are
inserted generally by compression, or even without compression in some devices
wherein the container is provided with a porous septum, permeable to the passage
of gases but able to retain powders; the latter configuration is particularly suitable
for the application of the "fly wheels", wherein powder of a moisture sorber
material, such as calcium oxide, can be additioned to the getter alloy. Some of
these possibilities are represented in figures 1 to 5, wherein figure 1 shows a pellet
10 made only of compressed powders of NEG alloy according to the invention.
Figure 2 represents a NEG device 20, having a shape particularly suitable for the
use in lamps, obtained by cutting along parallel lines, orthogonal to the
longitudinal direction, a band 21 formed of a metal support 22 on which powders
23 of an alloy of the invention are present; the next device of the type 20 is
obtained by cutting the band along dotted line A-A'. Figure 3 shows in section a
device 30 formed of an upperly open metal container 31, wherein powders 32 of
NEG alloy are provided. Figure 4 shows in section a device 40 formed of a metal
container 41 wherein powders 42 of a NEG alloy are provided, having an upper
opening closed by a porous septum 43. Finally, figure 5 shows a device 50 similar
to that of the preceding drawing and particularly suitable in the application "fly
wheels", wherein powders of a NEG alloy 51 of the invention and powders of a
moisture sorbing material 52 are provided.
The invention will be now further illustrated by means of the following
examples. These non limiting examples show some embodiments which are
intended to teach those skilled in the art how to put the invention into practice and
to represent the best considered way for carrying out the invention.
EXAMPLE 1
This example relates to the preparation of an alloy of the invention. 100 g of
'an alloy having the composition Zr 70% - V 15% - Fe 3.3% - Mn 8.7% - MM 3%
are produced by melting in an induction oven, in proportions corresponding to the
desired composition, Zr, Mn, J&M)and a commercial V-Fe alloy containing about
81.5% by weight of vanadium. The mischmetal used has the weight percent
composition of 50% cerium, 30% lanthanum, 15% neodymium, and the remaining
5% of other Rare Earths. The alloy ingot is ground under an argon atmosphere, in
a pall mill and the powder is sieved, thus recovering the fraction having particle
size of 40-128 urn.
EXAMPLE 2
This example relates to the preparation of a second alloy of the invention.
The test of example 1 is repeated, but starting from different quantities of Zr, Mn,
MM and V-Fe alloy, so as to obtain an alloy having composition Zr 69% - V 2.6%
- Fe 0.6% - Mn 24.8% - MM 3%.
EXAMPLE 3 (COMPARATIVE)
This example relates to the preparation of an alloy according to the known
art, to be used for example in the following examples; this alloy is taken as a
reference because it is the NEG material which is most commonly used in
application such as thermal insulation and gas purification. 100 g of St 707 alloy
are produced, by operating as described in example 1, by using Zr and V-Fe alloy
in proportions corresponding to the desired composition.
EXAMPLE 4
This example refers to a measure of the nitrogen sorption properties by an
alloy of the invention. 0.2 g of powder prepared in example 1 are activated at
500°C for 10 minutes, and are then introduced in a measure chamber. The
nitrogen sorption test is carried out by following the procedure described in
standard ASTM F 798-82, by operating at the room temperature and with a
nitrogen pressure of 4 x 10"6 mbars. The test results are reported in a graphic as
curve 1 in figure 6, as sorption velocity (indicated with S and measured in cm3 of
gas sorbed per second, normalized per gram of alloy) as a function of the quantity
of sorbed gas (indicated with Q and measured in cm3 of gas multiplied by the
pressure of measure in mbars and normalized per gram of alloy).
EXAMPLE 5
The test of example 4 is repeated, by using 0.2 g of powder of example 2.
The results of the test are reported in a graph as curve 2 in figure 6.
EXAMPLE 6 (COMPARATIVES
The test of example 4 is repeated by using 0.2 g of powder of example 3.
The test results are reported in a graph as curve 3 in figure 6.
EXAMPLE 7
The test of example 4 is repeated, but using CO as the test gas. CO is used
as the test gas because it is one of the gases which are found most commonly in
evacuated spaces, such as the interspaces for thermal insulation. The test results
are reported in a graph as curve 4 in figure 7.
EXAMPLE 8
The test of example 7 is repeated by using 0.2 g of powder of example 2.
The test results are reported in a graph as curve S in figure 7.
EXAMPLE 9 (COMPARATIVES
The test of example 7 is repeated, by using 0.2 g of powder of example 3.
The test results are reported in a graph as curve 6 in figure 7.
EXAMPLE 10
The test of example 4 is repeated, but using hydrogen as the test gas.
Hydrogen, together with CO, is one of the gases present in greatest quantity in
evacuated spaces. The test results are reported in a graph as curve 7 in figure 8.
EXAMPLE 11
The test of example 10 is repeated, by using 0.2 g of powder of example 2.
The test results are reported in a graph as curve 8 in figure 8.
EXAMPLE 12 (COMPARATIVE)
The test of example 10 is repeated, by using 0.2 g of powder of example 3.
The test results are reported in a graph as curve 9 in figure 8.
EXAMPLE 13
The test of example 4 is repeated, but maintaining in this case the sample at
300 °C during the test. The test results are reported in a graph as curve 10 in
figure 9.
EXAMPLE 14 (COMPARATIVE)
The test of example 13 is repeated, by using 0.2 g of powder of example 3.
The test results are reported in a graph as curve 11 in figure 9.
EXAMPLE 15
The test of example 4 is repeated, by using in this case, instead of loose
powders, a 2 mm high pellet, having 4 mm of diameter and about 125 mg of
weight, produced with the powder prepared as described in example 1. The results
of the test are reported in a graph as curve 12 in figure 10.
EXAMPLE 16 (COMPARATIVE)
The test of example 15 is repeated, by using a pellet of powder according to
example 3, having the same size as the pellet of example 15. The results of the test
are reported in a graph as curve 13 in figure 10.
EXAMPLE 17
The test of example 15 is repeated, by using this time CO as the test gas.
The results of the test are reported in a graph as the curve 14 in figure 11.
EXAMPLE 18 (COMPARATIVE)
The test of example 17 is repeated, by using a pellet of powder of example 3
having the same size of the pellet of example 17. The results of the test are
reported in a graph as curve 15 in figure 11.
A particularly important factor for evaluating a NEG alloy for practical
applications, above all when working at room temperature is foreseen, is the
sorption capacity at a certain sorption velocity. In feet, in the normal applications
the theoretical sorption capacity of the NEG alloys, which is determined as the
stoichiometric completion of the reaction between the metal components and the
sorbed gases, is never reached, and generally the lower is the working
temperature, the smaller is the degree of progress of said reaction. Therefore, from
the practical point of view, it is assumed as the capacity of a getter alloy the one at
which its sorption velocity has decreased, from the initial value, to a mi-nii-niTm
value acceptable for the application; further, it is assumed that this mi-m-m^rn
value is equal to the velocity with which the gases penetrate inside the evacuated
space, because of release or permeation from the walls; in the case of applications
in purification, said minimum value must be at least equal to the flow of the
impurities which come onto the alloy. These practical conditions ensure that the
getter alloy is able to absorb completely the quantity of gaseous impurities with
which it is in contact. By analyzing the results of the tests it can be noticed that
the alloys of the invention have gas sorption properties better than the alloy St
707; particularly, the capacity for nitrogen at room temperature is about 5-15
times greater than the alloy St 707 in the case of loose powders (fig. 6), and about
•3-5 times greater in the case of pellets (fig. 10); the capacity for CO at the room
temperature is about 3-5 times greater than for the St 707 alloy in the case of loose
powders (fig. 7) and about 6-10 times greater in the case of pellets (fig. 11); the
capacity for hydrogen of the powder alloys of the invention is better than that of
the alloy St 707 at the room temperature (fig. 8); finally, even at 300 °C powders
of an alloy of the invention show nitrogen capacities higher than powders of the
alloy St 707 (fig. 9).
The applicant hereby asserts that the "non-evaporable getter alloys" and the
"getter devices made of said alloys", as claimed herein, are not products or
substances useful for, or relate to, the production, control, use or disposal of atomic
energy or the prospecting, mining, extraction, production, physical and chemical
treatment, fabrication, enrichment, canning, nor the use of zirconium as one of the
alloying elements of the claimed alloys has relation, in any manner whatsoever, to
the use or production of atomic energy or research into matters connected therewith
or for atomic energy operations.
WE CLAIM :
1. Non-evaporable getter alloys having high gas sorption efficiency,
particularly for nitrogen, comprising zirconium, vanadium, iron, manganese
and at least one element selected from yttrium, lanthanum and Rare Earths,
having a weight percent composition of the elements which can vary within
the following ranges :
- zirconium from 60 to 85% ;
- vanadium from 2 to 20% ;
- iron from 0.5 to 10% ;
- manganese from 2.5 to 30% ;
- yttrium, lanthanum and Rare Earths or mixtures thereof from 1 to
6%.
2. Alloys as claimed in claim 1, wherein the weight percentage of
zirconium is comprised between about 65 to 75%.
3. Alloys as claimed in claim 2, wherein the weight percentage of
zirconium is comprised between about 67 and 70%.
4. Alloys as claimed in claim 1, wherein the weight percentage of
vanadium is comprised between about 2.5% and 15%.
5. Alloys as claimed in claim 1, wherein the weight percentage of
manganese is comprised between about 5 and 25%.
6. Alloys as claimed in claim 1, wherein the weight ratio between iron
and vanadium is between 1:4 and 1:5.
7. Alloys as claimed in claim 1 having the composition Zr 70% - V
15% - Fe 3.3% - Mn 8.7% - mischmetal 3%.
8. Alloys as claimed in claim 1 having the composition Zr 69% - V
2.6% - Fe 0.6% - Mn 24.8% - mischmetal 3%.
9. Getter devices formed of, or comprising, powders of non-
evaporable getter alloys comprising zirconium, vanadium, iron, manganese
and at least one element selected among yttrium, lanthanum and Rare
Earths, said alloys having a weight percent composition of the elements
which can vary within the following ranges :
- zirconium from 60 to 85% ;
- vanadium from 2 to 20% ;
- iron from 0.5 to 10% ;
- manganese from 2.5 to 30% ;
- yttrium, lanthanum and Rare Earths or mixtures thereof from 1 to
6%.
10. Devices as claimed in claim 9, wherein said alloys have particle
size lower than 250 urn.
11. Devices as claimed in claim 9, wherein the powders have particle
size comprised between 125 and 40 urn.
12. Devices (10) as claimed in claim 9, formed of pellets made only of
powders of the getter alloy.
13. Devices (20) as claimed in claim 9, obtained cutting along parallel
lines in the longitudinal direction a band (21) formed of a metal support (22)
on which powders (23) of a getter alloy are provided.
14. Devices (30) as claimed in claim 9, formed of powders of a getter
alloy (32) inside an upperly open metal container (31).
15. Devices (40) as claimed in claim 9, formed of powders of a getter
alloy (42) inside a metal container (41) having an upper opening closed by a
porous septum (43).
16. Devices (50) as claimed in claim 15 containing, besides the
powders of the getter alloy (51), powders of a moisture sorbing material (52).
17. Thermally insulating manufactured articles comprising an
evacuated interspace, wherein the interspace comprises an alloy as claimed
in claim 1.
18. Manufactured articles as claimed in claim 17 wherein said
interspace contains getter devices as claimed in claim 11.
19. Gas purifiers containing an alloy as claimed in claim 1.
20. Purifiers as claimed in claim 19, containing getter devices as
claimed in claim 12.
21. Lamps containing an alloy as claimed in claim 1.
22. Lamps as claimed in claim 21, containing getter devices as claimed
in claim 13.
23. Evacuated chambers of inertial energy accumulators containing an
alloy as claimed in claim 1.
24. Chambers as claimed in claim 23 containing devices as claimed in
claim 15.
25. Chambers as claimed in claim 23 containing devices as claimed in
claim 16.
26. Non-evaporable getter alloys, substantially as herein described,
particularly with reference to and as illustrated in the accompanying drawings.
27. Getter devices formed of, or comprising, powders of non-
evaporable getter alloys, substantially as herein described, particularly with
reference to and as illustrated in the accompanying drawings.

Non-evaporable getter alloys zirconium, vanadium, iron, manganese and one or more elements selected among yttrium, lanthanum and Rare Earths are described having improved features of gas sorption, particularly of nitrogen, with respect to the known getter alloys.

Documents:

in-pct-2002-32-kol-abstract.pdf

in-pct-2002-32-kol-assignment.pdf

in-pct-2002-32-kol-assignment1.1.pdf

in-pct-2002-32-kol-claims.pdf

IN-PCT-2002-32-KOL-CORRESPONDENCE.pdf

in-pct-2002-32-kol-correspondence1.1.pdf

in-pct-2002-32-kol-description (complete).pdf

in-pct-2002-32-kol-drawings.pdf

in-pct-2002-32-kol-examination report.pdf

in-pct-2002-32-kol-examination report1.1.pdf

in-pct-2002-32-kol-form 1.pdf

in-pct-2002-32-kol-form 18.1.pdf

in-pct-2002-32-kol-form 18.pdf

in-pct-2002-32-kol-form 3.1.pdf

in-pct-2002-32-kol-form 3.pdf

in-pct-2002-32-kol-form 5.1.pdf

in-pct-2002-32-kol-form 5.pdf

IN-PCT-2002-32-KOL-FORM-27.pdf

in-pct-2002-32-kol-gpa.pdf

in-pct-2002-32-kol-gpa1.1.pdf

in-pct-2002-32-kol-granted-abstract.pdf

in-pct-2002-32-kol-granted-claims.pdf

in-pct-2002-32-kol-granted-description (complete).pdf

in-pct-2002-32-kol-granted-drawings.pdf

in-pct-2002-32-kol-granted-form 1.pdf

in-pct-2002-32-kol-granted-specification.pdf

in-pct-2002-32-kol-priority document.pdf

in-pct-2002-32-kol-reply to examination report.pdf

in-pct-2002-32-kol-reply to examination report1.1.pdf

in-pct-2002-32-kol-specification.pdf

in-pct-2002-32-kol-translated copy of priority document.pdf

in-pct-2002-32-kol-translated copy of priority document1.1.pdf


Patent Number 242629
Indian Patent Application Number IN/PCT/2002/32/KOL
PG Journal Number 36/2010
Publication Date 03-Sep-2010
Grant Date 02-Sep-2010
Date of Filing 08-Jan-2002
Name of Patentee SAES GETTERS S.P.A.
Applicant Address VIALE ITALIA, 77, I-20020, LAINATE
Inventors:
# Inventor's Name Inventor's Address
1 TOIA LUCA VIA DELLA FONTANA, 14/A, I-21040 CARNAGO
2 BOFFITO CLAUDIO VIA PAPA GIOVANNI XXIII 2, I-20017 RHO
PCT International Classification Number C22C 16/00
PCT International Application Number PCT/IT2001/00269
PCT International Filing date 2001-05-28
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 MI2000A001200 2000-05-30 Italy