DE2245120A1 - TUNGSTEN BODY RESISTANT AT HIGH TEMPERATURES - Google Patents

Description

EGYESÜ1T IZZOIiAMPA ES VILLAMOSSAGI BESZVENYTARSASAG Budapest IV., Ujpest Vaci ut 77.

Tungsten body resistant to high temperatures

The invention relates to a device that is dimensionally stable at high temperatures Tungsten bodies for the production of incandescent bodies (coils) for halogen-filled lamps and probe lamps, which contains conventional additives such as K, Si, Al or additives that replace them.

Before describing the invention, the technical background will be briefly discussed.

The tungsten body used in electric light bulbs operates under very severe conditions. In addition to a long service life, the incandescent body must have good dimensional stability and have evaporation properties. These favorable properties must be found in today's halogen-filled Lamps can be guaranteed even at higher temperatures and in an aggressive atmosphere.

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For such changed operating conditions, the properties the conventional tungsten materials with K, Si »Al additives can be further improved. So is E.B. after the DT - FS 1.608.138 the potassium beneficial duroh thallium to replace, where the annoying Liohtbogenbrand can be reduced with some lamp types. Knowing the Patents describing conventional additives - e.g. US 1.410o499 and 2.012.825 or the Hungarian patent Ir. 155.352, the effect of the additives can be summarized as follows will:

During the known powder metallurgical production of tungsten metal, the additional materials mostly evaporate as a result of the action of heat (sintering, mechanical shaping, annealing), and less than 20 ppm of them remain in the conventional metals marked with GK, e.g. containing K, Si, Al. The changes remaining at the point of the evaporated additives, such as the additives remaining in the metal, jointly influence the crystallization and this determines the properties of the metal, for example the dimensional stability. The amount of additives remaining in the metal and their effect can be ^{reduced to a large extent at the operating temperature of the helix (2400 to 3000 0} O) and in the presence of aggressive gas contaminants at considerably lower temperatures. Accordingly, the filament gradually changes its shape during operation, as a result of which the incandescent lamp dies prematurely. Another disadvantage arises from the fact that, because of the evaporation of most of the K, Si and Al additives, it is very difficult to reliably distinguish these types of materials from other types of tungsten in the course of mass production.

The invention is based on the object to provide a folfram body

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to create by the type described at the beginning high temperatures Retains its shape for a long time.

This object is achieved by the features listed in the claim «incandescent bodies, i.e. coils made from tungsten compositions according to the invention and have been built into known Halogeniaapen, even after several thousand hours of operation retain their original shape while ssur same With lamps made from tungsten with a conventional composition, the filament already sags could be observed after a few hundred burning hours

The knowledge according to the invention is therefore that the conventional additives with such a material or such Materials are to be supplemented, which even after the reduction of the quantities, or after the above-mentioned has become ineffective Substances, in a pseudomorphic arrangement, at least 80ji of the original amount remain in the Wolf ramme tall, even after buckets lasting several thousand hours Operation of the lamp, and so continuously even at high temperatures ensure the desired mechanical-physical properties

It was determined that for the particularly difficult requirements for halogen-filled incandescent lamps a higher Ti content, e.g. up to 500 ppm, and for the requirements of normal Incandescent lamps a lower, e.g. 20 ppm! Egg content makes the tungsten body the most suitable

Such a small Ti content, e.g. 20 ppm, is already completely sufficient to ensure that the tungsten body of other tungsten bodies which do not contain Ti or which contain Ti in a larger proportion by a spectral

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Investigation at any stage of manufacture or in the end product can be safely distinguished

The process according to the invention is illustrated by the following examples

1) of known type - for example, by cutting and preparation of ammonium paratungstate - produced 0.2 ^ K, 0.15 Si, and 0.02 i> Al-containing tungsten oxide of 0.7 i »GrlUhverlust with a 0.02 i" Xi corresponding amount of Xiol, solution blended · This substance is dried under agitation and heated to 300 ⁰ C. After not border the powder in a known manner in a H "-8trom at 650 ⁰ C temperature reduced to metal · The metal powder is - also known catfish - pressed into rods and 94 of Durohsohmelzatromes t sintered"

In the tungsten body obtained in this way, there are 2Θ0 ppm titanium, as well as to find 20 ppm each of K, Si and Al, so that is relationship

Ti
about 5.

K + Si f Al

The filament made from the rod in a known manner is installed in 230 V, 5000 W halogen floodlight lamps. The helix did not change its shape measurably during life and the weight loss that occurred during the same period of time did not change measurably due to evaporation was 1 # smaller than that in which helix made with conventional additives.

2) The filament produced according to Example 1 was inserted into a 220 V, 150 W projection lamp which did not contain a halogen component built-in! The properties of the filament are essentially identical to those in the example during operation of the lamp 1 described above

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3) The tungsten oxide according to Example 1 was treated with an amount of zirconium nitrate corresponding to 0.01 i * Zr instead of Ti, and a filament and an incandescent lamp were produced at the same time according to Example 1 or 2. The helix had essentially the same properties as those in Example 1 *

4) Bas tungsten oxide according to Example 1 was with a 0.02 ^ 6 Ii and 0.002 jt Zr corresponding amount of XiOl, and Zr nitrate treated and also according to Example 1 or 2 has a filament and an incandescent lamp produced the filament exhibited essentially the same properties as those in Example 1.

5) The tungsten oxide according to Example 1 was treated with an amount of XiOl corresponding to 0.002 Xi and worked up in the usual way to give a 220 V ₉ 4OW standard lamp filament. During the work-up of metals · resulting semi-finished products (rod, wire, coil) may be used in mass production, Z ₀ B. duroh a spektrographlsohe method are identified and prepared by the conventional or manufactured with other additional components tungsten locations, as well as the halogen-filled lamps A distinction is made between products with a higher titanium content. As a comparison, some measured values are given here which confirm the favorable properties of the tungsten bodies containing Ti-Zr.

Tensile strength Gemeflen with a Gemeflen with a Og kg / mm ² 0 0.185 mm Ti ₉ Zr ff 0.185 mm Ii ₉ Zr

containing wire not containing

wire

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22A512Ü

At room temperature

299 290

At 1850 ⁰ O 7.92 8.42

Stretch + fat Room temperature 3.4 2.7

At 1850 ⁰ O 30.8 22.5

In the inventive material of grfSfite part occurs strain at the höohaten Zerreilkraft what ore in terms of dimensional stability at high temperature "low · Bin is further Torteil de · erfindungsgemÄflen GUUhkörpere is DAFL this at raaohen glowing of - inebesondere above 2400 ⁰ O - Noticeably less vaporized than conventional tungsten · toffΒ. This browning is nooh more intense when glowing in a carbon-containing atmosphere. This is of particular importance when the halogen component is introduced into the lamp in the form of a halogen-containing hydrocarbon compound.

- claim -

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Claims (1)

Claimed Tungsten body that retains its shape at high temperatures for the production of G-glow bodies (coils) halogen-filled Lamps and special lamps that use conventional accessories such as B »K, Si» Al or these replacing additions contains »characterized in that, in addition to these additives, it contains titanium and / or zirconium in the order of magnitude Contains from 20 to 500 ppm and the ratio of the amount of titanium and / or zirconium to the common The amount of K, Si and Al in the finished tungsten body is one Value is between 1 and 10. _D · H- ^ resting Patent attorney 309813/0832