JPS5840768A - Rhenium-tungsten alloy wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rhenium-tungsten (hereinafter abbreviated as Re-W) alloy wire, and particularly to a Re-W alloy wire suitable for vibration-resistant tube filaments.

Compared to pure tungsten, Re-W alloy has various advantages such as high electrical resistance, flexibility and workability, and a high melting point, so it is used as a filament for light bulbs, electron tubes, etc. In recent years, its uses have been expanding more and more.

After the thin wire made of such Re-W alloy is assembled into a tube as a filament, it is flushed, that is, a current is passed through the filament for a short period of time to clean the inside of the tube and check its operation. However, at this time, the filament is heated at a high temperature, and secondary recrystallization is performed on the Re-W alloy structure.

Therefore, if the secondary recrystallized structure is not long aligned in the direction of the crystal axis and the grain boundaries of the crystal are close to perpendicular to the axis, the vibration during lighting will cause the crystal to The organization shifts,
There was an interlayer that became hotter than other parts and eventually broke.

The present invention was made to solve this problem, and contains rhenium in a weight ratio of 0.3 to 5%, and the L/w value of the secondary recrystallized II fiber is 1.2 or more. We would like to provide a Re-W alloy wire in which the value of L is 2 μ or more (L indicates the length of the crystal in the axial direction, and W indicates the length of the crystal in the direction perpendicular to this). That is.

In the present invention, the content of rhenium is 0.3 to 0.3 by weight.
The reason for limiting the content to 5% is that if the content is less than 0.3%, the desired vibration resistance and wire flexibility cannot be obtained as a lamp, and if the content exceeds 5%, processing will be required. bad sex,
This is because the melting point and creep strength are lowered, making it unsuitable for use in tubes, etc.

Further, as described above, in order to prevent crystals from shifting at grain boundaries, it is desirable that the number of crystal grains be two or more in a cross section perpendicular to the axial direction of the line.

The Re-W alloy wire of the present invention further contains silicon, aluminum, and potassium in the form of oxides of o, oos to 0.
By adding and containing 1%, creep strength etc. can be further improved.

The Re-W alloy wire of the present invention has a secondary recrystallized structure composed of long crystals extending in the axial direction, with an L/w value of 1.2 or more and an L value of 2μ or more. However, as conditions for secondary recrystallization, the thermogeographical conditions described below are desirable.

That is, it is preferable to perform the heat treatment in a hydrogen atmosphere at a brightness temperature of 2450° C. for 5 minutes, and these conditions correspond to the conditions for the flashing treatment during normal tube manufacturing.

Examples and comparative examples will be described below.

MG/200 (
Wire rod 200111 length and weight (wire diameter unit expressed in 9 grams) Te20 MG f) Re-W wire, 245
Heat treatment was performed at 0° C. in a hydrogen atmosphere to secondary recrystallize the crystal structure. The crystal structure was observed using a metal microscope, and L
and W values were measured.

Next, a tensile strength test was conducted on the Re-W wire. The test results are shown in Table 1.

Further, the tensile strength tests for these Examples and Comparative Examples were conducted under the conditions of a gage distance of 50 cm and a tensile rate of 10 cm/m.

Furthermore, these Re-W wires were incorporated into lamps, and the deformation (deformation) and vibration resistance after brushing treatment were compared. Deformation should be visually inspected to ensure that there is no problem in practical use.
”. In addition, for vibration resistance, those that broke within 6 hours in the 8AE fly impact drum test were rated "x".

Table 1 As is clear from Table 1, the Re-W line of the present invention is composed of long crystals in which the secondary recrystallized structure extends in the axial direction,
Since it has a structure in which the crystal grain boundaries intersect with each other in a zigzag manner, it is particularly suitable as a filament for tubes with high bending properties and tensile strength.

(7317) Representative Patent Attorney Noriyuki Chika (and 1 other person)

Claims (1)

[Claims] 1 Contains 0.3 to 5% rhenium by weight, and the value of L/w is 1, where the length in the axial direction of the crystal is defined as W, and the length in the direction perpendicular to this is defined as W. A rhenium-tungsten alloy wire characterized by having a secondary recrystallized structure in which L is .2 or more and L is 2μ or more. 2. The rhenium-tungsten alloy 1m according to claim 1, wherein the number of crystal grains is 2 or more in a cross section perpendicular to the axial direction of the line. 3. Secondary recrystallization was performed by heating at a brightness temperature of 2450°C for 5 minutes in a hydrogen atmosphere.