CN100395363C - Tungsten-rhenium alloy rod for ion source of ion implanter and preparation method thereof - Google Patents

Abstract

The invention discloses a tungsten-rhenium alloy rod for an ion source of an ion implanter and a preparation method thereof. The tungsten-rhenium alloy rod is composed of elongated crystal grains with an interlocking structure, the aspect ratio of the crystal grains is greater than 10, and its composition content is: rhenium : 0.2%～0.9wt.%, it also contains dopant, and the balance is tungsten. Because a certain amount of rhenium is added to tungsten, it overcomes the shortcomings of traditional tungsten rods, and has the characteristics of high melting point, high strength, high hardness, high resistivity, high recrystallization temperature, etc., especially low electron escape Work, which acts as an ion source filament, increases the intensity of ion emission.

Description

Tungsten-rhenium alloy rod for ion source of ion implanter and preparation method thereof

technical field

The invention relates to a tungsten material for an ion source of an ion implanter and a preparation method thereof.

Background technique

Ion implantation technology is a high-tech material surface modification technology that has been vigorously developed and widely used internationally in the past 30 years. The basic principle is: use an ion beam with an energy of 100keV to enter the material, a series of physical and chemical interactions will occur between the ion beam and the atoms or molecules in the material, the incident ions will gradually lose energy, and finally stay in the In the material, and cause the surface composition, structure and performance of the material to change, so as to optimize the surface performance of the material, or obtain some new excellent performance. As a material surface engineering technology, ion implantation technology has the following unique advantages that are difficult to achieve by other conventional surface treatment technologies: (1) It is a pure and pollution-free surface treatment technology; It is carried out in a high temperature environment, so it will not change the dimensions and surface finish of the workpiece; (3) The ion implantation layer is a new surface layer formed by a series of physical and chemical interactions between the ion beam and the surface of the substrate. There is no peeling problem; (4) No need for mechanical processing and heat treatment after ion implantation.

Ion implantation is performed on an ion implanter. An ion implanter generally consists of the following main parts: (1) ion source, which is used to generate and extract an ion beam of a certain element, which is the source of the ion implanter; (2) accelerator; (3) the quality of the ion beam Analysis; (4) Confinement and control of ion beam; (5) Target chamber; (6) Vacuum system.

Among them, the ion source is the "heart" of the ion implanter. The filament materials used in the existing ion implanter are generally pure tungsten rods, doped tungsten rods, and special alloy tungsten rods added with thorium oxide. The high work function of electrons on the surface of tungsten rods is not conducive to the emission of electrons; with the strengthening of people's awareness of environmental protection, the application of thoriated tungsten rods is becoming more and more restricted.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a tungsten-rhenium alloy rod for ion implanter ion source used as ion implanter ion source filament and its preparation method.

The technical solution adopted by the present invention to solve the technical problem is: a tungsten-rhenium alloy rod for the ion source of an ion implanter, which is composed of grains of interlocking elongated structure, the aspect ratio of the grains is greater than 10, and its composition content: Tungsten: ≥99.1wt.%, Rhenium: 0.2% to 0.9wt.%, which also contains dopants.

The dopant includes potassium, and its potassium content is 60-100PPm.

The dopant includes silicon, and the content of silicon is 5-10PPm.

The dopant includes aluminum, and the content of aluminum is 5-15PPm.

A kind of preparation method of the tungsten-rhenium alloy rod for the ion source of the ion implanter of the present invention, it comprises the following steps:

a. Raw materials: Doping potassium, silicon and aluminum in blue tungsten by soaking, adding rhenium in the form of ammonium perrhenate solution, stirring, evaporating and drying to obtain a spare powder;

b. Molding: press the spare powder into shape;

c. Pre-sintering: The powder is pressed and pre-sintered in a hydrogen atmosphere at 1000-1400 ° C. The pre-sintering time is 0.3-1 hour;

d. Sintering: The pre-sintered billet is sintered at a temperature of 2600-3000°C under the protection of hydrogen, and the vertical melting sintering time is 1-2 hours;

e. Billet opening: gradually process the thick billet to the size that can be drawn;

f. Wire drawing: Forging, rolling and drawing the blanked vertical melting rod to obtain a doped tungsten-rhenium alloy rod.

g. Forming: Straighten and cut the above-mentioned tungsten-rhenium alloy rod into required size.

The beneficial effect of the present invention is that due to the addition of a certain amount of rhenium in tungsten, it overcomes the shortcomings of traditional tungsten rods, and has the characteristics of high melting point, high strength, high hardness, high resistivity, high recrystallization temperature, etc., especially Is the lower electron work function, which acts as an ion source filament, increasing the ion emission intensity.

Description of drawings:

Fig. 1 is the flow chart of the preparation method of tungsten-rhenium alloy rod for ion implanter ion source of the present invention;

Fig. 2 is the metallographic structure diagram of the embodiment of the present invention one tungsten-rhenium alloy;

Fig. 3 is the metallographic structure diagram of the ditungsten-rhenium alloy of the embodiment of the present invention;

Fig. 4 is the metallographic structure diagram of the tritungsten-rhenium alloy of the embodiment of the present invention;

Detailed ways

The present invention will be further described in detail below in conjunction with the examples; however, the preparation method of the tungsten-rhenium wire for the ion source of the ion implanter of the present invention is not limited to the examples.

Embodiment 1, the present invention is a kind of preparation method of tungsten-rhenium rod for ion source of ion implanter, it comprises the following steps, as shown in Figure 1:

a. Raw materials: dope potassium, silicon and aluminum in blue tungsten by soaking, add rhenium in the form of ammonium perrhenate solution, stir, evaporate, dry, and reduce to obtain tungsten-rhenium alloy powder;

b. Molding: pressing tungsten-rhenium alloy powder into shape;

c. Pre-sintering: The powder is pressed and pre-sintered in hydrogen at 1000-1100 °C, and the pre-sintering time is 0.5 hours;

d. Sintering: The pre-sintered billet is sintered at a temperature of 2600-2700°C under the protection of hydrogen, and the vertical melting sintering time is 1.2 hours;

e. Billet opening: gradually process the thick billet to the size that can be drawn;

f. Wire drawing: Forge, roll and draw the vertically molten bar that has been billeted to obtain a doped tungsten-rhenium alloy rod. The composition and content: rhenium: 0.3wt.% potassium: 60PPm, silicon: 5PPm, aluminum: 5PPm, the balance for tungsten.

g. Forming: Straighten and cut the above-mentioned tungsten-rhenium alloy rod into required size.

After the above seven-step process, a tungsten-rhenium alloy rod can be obtained. The grain width ratio is greater than 10, and the sag value is 1.2. The ion implanter with its ion source on.

Embodiment two, the present invention is a kind of preparation method of tungsten-rhenium wire for ion source of ion implanter, it comprises the following steps:

a. Raw material: dope potassium, silicon and aluminum in blue tungsten by soaking, add rhenium in the form of ammonium perrhenate solution, stir, evaporate, dry, and reduce to obtain tungsten-rhenium alloy powder;

b. Molding: pressing tungsten-rhenium alloy powder into shape;

c. Pre-sintering: The powder is pressed and pre-sintered in hydrogen at 1200-1100 ° C. The pre-sintering time is 0.8 hours;

d. Sintering: The pre-sintered billet is sintered at a temperature of 2800-2900°C under the protection of hydrogen, and the vertical melting sintering time is 1.5 hours;

e. Billet opening: gradually process the thick billet to the size that can be drawn;

f. Wire drawing: forging, rolling and drawing the vertical melting rod after billeting to obtain a doped tungsten-rhenium alloy rod, its composition and content: rhenium: 0.6wt.%, potassium: 80PPm, silicon: 8PPm, aluminum: 10PPm, and The amount is tungsten.

g. Forming: Straighten and cut the above-mentioned tungsten-rhenium alloy rod into required size.

After the above seven-step process, a tungsten-rhenium alloy rod can be obtained, with a grain width ratio greater than 10 and a sag value of 0.8. The high-temperature metallographic structure is shown in Figure 3 .

Embodiment three, the present invention is a preparation method of tungsten-tungsten-rhenium wire for ion source of ion implanter, which comprises the following steps:

a. Raw material: dope potassium, silicon and aluminum in blue tungsten by soaking, add rhenium in the form of ammonium perrhenate solution, stir, evaporate, dry, and reduce to obtain tungsten-rhenium alloy powder;

b. Molding: pressing tungsten-rhenium alloy powder into shape;

c. Pre-sintering: The powder is pressed and pre-sintered in hydrogen at 1300-1400 ° C. The pre-sintering time is 0.1 hour;

d. Sintering: The pre-sintered billet is sintered at a temperature of 2800-2900 °C under the protection of hydrogen at high temperature, and the vertical melting sintering time is 1.8 hours;

e. Billet opening: gradually process the thick billet to the size that can be drawn;

f. Wire drawing: forging, rolling and drawing the vertical melting rod after billeting to obtain a doped tungsten-rhenium alloy rod, its composition and content: rhenium: 0.8wt.%, potassium: 100PPm, silicon: 10PPm, aluminum: 15PPm, and The amount is tungsten.

g. Forming: Straighten and cut the above-mentioned tungsten-rhenium alloy rod into required size.

After the above seven-step process, the tungsten-rhenium alloy wire can be obtained, the grain width ratio is greater than 10, the sag value is 0.6, and its high-temperature metallographic structure is shown in Figure 4.

Claims (3)

1. ion implanter ion source W-Re alloys bar, form by the interlocking structure elongated grains, the length and width ratio of crystal grain is greater than 10, its component content: rhenium: 0.3%～0.9wt.%, reach trace doped dose of potassium, silicon, aluminium, the content of its potassium is 60～100PPm, and the content of its silicon is 5～10PPm, the content of its aluminium is 5～15PPm, and surplus is a tungsten.

2. a kind of ion implanter ion source according to claim 1 preparation method of W-Re alloys bar, it comprises the steps:

A. raw material: with immersion way doped with potassium, silicon, aluminium in blue tungsten, add rhenium, obtain standby powder through stirring, evaporation, drying with the form of ammonium perrhenate solution;

B. die mould: with standby powder pressing forming;

C. presintering: powder is through die mould, presintering in 1000～1400 ℃ of hydrogen atmospheres, and the presintering time is 0.3～1 hour;

D. sintering: through the high temperature incipient fusion sintering under 2600～3000 ℃ of temperature and hydrogen shield of the base bar after the presintering, the incipient fusion sintering time is 1～2 hour;

E. cogging: with thick base bar be machined to gradually can drawing size;

F. wire drawing: will obtain Doped Tungsten rhenium alloys bar through incipient fusion bar forging rolling, the drawing of cogging.

G. moulding: with above-mentioned W-Re alloys rod straightening, cut into desired size.

3. a kind of ion implanter ion source according to claim 2 preparation method of W-Re alloys bar, it is characterized in that: described tungsten is blue tungsten.

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