TWI387661B - Manufacturing method of nickel alloy target - Google Patents

Description

Nickel alloy target manufacturing method

The present invention relates to a method for producing a target, and more particularly to a method for producing a nickel alloy target.

Referring to the Chinese Patent No. 200510104828.2 and No. 200610076274.4, it discloses a manufacturing technique of powder metallurgy, which firstly mixes high-purity nickel (Ni) powder and tungsten (W) powder by ball milling, and then loads it into a graphite mold. The Ni-W alloy is obtained by sintering plasma sintering at 800 to 1200 ° C, pressure control at 30 to 80 MPa, and holding temperature for 10 minutes. Although these patents can produce a dense Ni-W alloy, they are mixed with Ni powder and W powder by a conventional powder mixing method because the density of Ni is 8.9 g/cm ³ and the density of W is 19.3 g/cm ³ . The difference in density is more than double. In the process of ball milling, the dense powder W is easily separated from the smaller density Ni powder, resulting in uneven powder mixing, which further affects the uniformity of the alloy composition after sintering.

In addition, the method of the above two patents adopts a conventional powder metallurgy process, and it is necessary to use expensive Ni powder and W powder having high purity (purity of 99.99%) and fine particle size (having a particle size of about 3 to 6 μm), so the prepared Ni -W alloys cost more. Furthermore, in the above two patents, only the Ni powder and the W powder are mixed by ball milling, and the Ni powder and the W powder are not alloyed during mixing. After sintering, the Ni powder and the W powder are dense due to the sintering reaction. However, it is not completely alloyed, and it is still apparent that Ni powder and W powder are separately present.

In addition, in the conventional powder process, the required powder mixing time is long, which takes about 8 to 24 hours, and the powder is easily mixed due to the high melting point powder density compared with the general metal powder during the mixing process, resulting in powder mixing. Unevenness, which in turn affects the uniformity of the composition of the target after sintering. Moreover, in the conventional smelting process, after the molten soup is cast and cooled, it is necessary to further perform hot rolling to refine the structure, which also takes several hours. Among them, in the solidification process of the conventional casting process, there are disadvantages such as shrinkage cavities, composition segregation, and coarse structure, so it is necessary to eliminate segregation of the ingot and refine the structure by a time-consuming hot rolling step.

Therefore, it is necessary to provide an innovative and progressive method of manufacturing nickel alloy targets to solve the above problems.

The invention provides a method for manufacturing a nickel alloy target, comprising the steps of: (a) providing a nickel metal and at least a first alloying element; (b) performing a vacuum melting step to form an alloy solution; (c) atomizing The alloy solution is formed to form a nickel alloy powder; (d) performing a sieving step to select a nickel alloy powder having a smaller than a set size; and (e) forming and densifying the nickel alloy powder to form a nickel alloy Target.

The method for manufacturing the nickel alloy target of the invention does not need to use the relatively expensive Ni powder and W powder as raw materials, does not need to use relatively expensive plasma sintering equipment for sintering of Ni and W powders, and does not need to be cooled. The rolling process and the recrystallization annealing treatment under the atmosphere protection can quickly and mass-prepare the nickel alloy target, so the manufacturing method is simple and the manufacturing time can be reduced. Furthermore, the nickel alloy target produced by the manufacturing method of the present invention has no component segregation, fine crystal grains, uniform crystal grain distribution and complete alloying, so that it has high sputtering quality.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart showing a method of manufacturing a nickel alloy target of the present invention. First, referring to step S11, a nickel metal and at least a first alloying element are selected, the first alloying element being selected from the group consisting of molybdenum (Mo), tungsten (W), tantalum (Ta), hafnium (Hf), ruthenium (Ru),铼 (Re), zirconium (Zr) or bismuth (Nb). The nickel metal and the first alloying element may be in the form of a block or a strip, and the first alloying element may also be in the form of a sheet, a powder or a crumb. Preferably, the nickel metal and the first alloying element have a purity greater than 99.9%, and the first alloying element has a weight percentage of 5% to 20%. In this embodiment, the first alloying element is a tungsten alloying element.

In other applications, in addition to the nickel metal and the first alloying element, a second alloying element may be included. The second alloying element is selected from the group consisting of iron (Fe), copper (Cu) or zinc (Zn), wherein the melting point of the second alloying element is lower than the melting point of the first alloying element. Preferably, the nickel metal is more than 50% by weight, the first alloying element is 5% to 20% by weight, and the remaining weight percentage is the second alloying element content.

In addition, before step S11, the method further comprises the steps of: removing (for example, using ultrasonic vibration) the oxides and contaminants of the nickel metal and the surface of the first alloy element by using an acidic solution; An ultrasonic solution of the nickel metal and the surface of the first alloy element by ultrasonic vibration; and drying the nickel metal and the first alloying element. Wherein, the acidic solution has a volume concentration of 95% or more, and the nickel metal and the acidic solution on the surface of the first alloying element are removed by deionized water. Preferably, the acidic solution is selected from the group consisting of hydrochloric acid or nitric acid.

Referring to step S12, a vacuum melting step is performed to melt the nickel metal and the first alloying element to form an alloy solution. In the present embodiment, the vacuum melting step is carried out in a vacuum induction melting furnace or a vacuum arc melting furnace, and the molten alloy solution is stirred by a magnetic field provided by an induction coil to make the composition of the molten alloy solution uniform. Preferably, the vacuum melting temperature is 1500 ° C to 1750 ° C, and the vacuum melting degree is 10 ^-3 torr or more.

Referring to step S13, the alloy solution is atomized to form a nickel alloy powder. In the present embodiment, the alloy solution is atomized by a high pressure inert gas such as argon (Ar) or nitrogen (N ₂ ). Preferably, the high pressure inert gas has a pressure of 1 to 5 MPa and a flow rate of 50 to 100 m/s.

Wherein, the method of the present invention further comprises a cooling step after step S13 to cool the atomized nickel alloy powder. For example, the present invention can cool the atomized nickel alloy powder by means of argon gas or nitrogen gas spraying or natural cooling.

Referring to step S14, a sieving step is performed to select a nickel alloy powder of a set size. Wherein, the set particle size is preferably less than 200 micrometers (μm). The sieving step can control the nickel alloy powder to have a smaller and more uniform particle size, so that the nickel alloy powder has a finer grain and a more uniform grain distribution after being formed into a nickel alloy target.

Referring to step S15, the nickel alloy powder is formed and densified to form a nickel alloy target, wherein the nickel alloy target of the present invention can be applied to a film sputtering process in the magnetic recording industry, the photovoltaic industry, or the semiconductor industry. In step S15, the forming and densification steps are carried out by a hot press process or a hot press process. Preferably, the molding and densification temperature is preferably from 800 ° C to 1200 ° C, and the molding and densification time is preferably from 0.5 to 3 hours.

According to the actual test results, in the manufacturing method of the present invention, the nickel metal and the first alloy element are placed in a vacuum furnace to spray the alloy solution with an inert gas to obtain a uniform nickel alloy powder, which only requires about 2 ~3 hours, and the composition of the nickel alloy powder and the target component are set to within 0.5 atomic percent (at.%). Then, only one to three hours of hot pressing or hot equalizing can be obtained to obtain a dense nickel alloy target. Therefore, the manufacturing method of the present invention can not only rapidly and quantitatively prepare a nickel alloy target containing a high melting point element, but also the composition and structure of the nickel alloy target are superior to the alloy target prepared by the conventional powder metallurgy and smelting process.

The invention is illustrated by the following examples, which are not intended to be limited to the scope of the invention.

Example 1:

This example is exemplified by the preparation of a raw material powder of a Ni-8W (at.%) target, wherein Ni-8W (at.%) represents an atomic percentage of Ni and W of 92:8. First, a nickel block and a tungsten piece are prepared according to a Ni-8W (at.%) alloy ratio, followed by a surface treatment step of the nickel block and the tungsten piece, and the nickel block and the tungsten piece are placed in a hydrochloric acid solution having a volume concentration of 95% or more. The surface oxide and oil stain are removed by ultrasonic vibration, and the nickel block and the tungsten piece are placed in deionized water, and the hydrochloric acid solution remaining on the surface is removed by ultrasonic vibration, and then dried.

Next, the acid-washed nickel block and the tungsten piece are placed in a crucible of a vacuum induction melting furnace and vacuumed, and after the vacuum reaches 10 ^-3 torr or more, the temperature is raised to 1500 ° C, and the nickel block in the crucible is After the tungsten sheet is completely melted, the temperature is maintained for 5 minutes to ensure that the high melting point tungsten sheet can be fully melted, and the molten metal soup liquid component is uniformly stirred under the magnetic field provided by the induction coil.

Next, the molten Ni-8W metal soup liquid was poured out from the crucible of the vacuum induction melting furnace, and the flow was controlled at 3 MPa, the flow rate was controlled at 50 m/s, and the molten Ni-8W metal soup was sprayed to make the mist. Formed into nickel alloy powder.

Then, the N ₂ gas is continuously sprayed in a cavity to accelerate the cooling of the atomized nickel alloy powder, and after the nickel alloy powder is cooled, the sieve step is further performed. In the present embodiment, the sieving step may use a sieving machine to remove the nickel alloy powder having a particle size of more than 150 μm or more, leaving a nickel alloy powder having a particle size of less than 150 μm.

Wherein, the grain size of the nickel alloy powder is about 10 μm, and according to the actual analysis result of the energy dispersive spectrometer (EDS), the nickel alloy powder prepared by the invention is completely alloyed, and the composition is Ni-7.8W ( At.%). In addition, it is known from the X-ray diffraction analysis that the nickel alloy powder prepared by the present invention only exhibits a diffraction peak of FCC of Ni, and does not exhibit a diffraction peak of BCC of B, which represents complete alloying of Ni and W. The composition is quite uniform.

Finally, after the stainless steel is sealed, the hot pressing process is carried out, and after holding at 900 ° C for 2 hours, a nickel alloy target having a grain size of 5 to 50 μm and completely alloyed can be obtained.

2 is a view showing the microstructure of a Ni-8W nickel alloy target obtained by the production method of the present invention, wherein the scale of the lower right corner is 20 μm, as is clear from FIG. 2, the nickel alloy target is not only It has fine grains and the distribution of these grains is very uniform.

Example 2:

This example is exemplified by the production of a raw material powder of a Ni-17Fe-8W (at.%) target. First, prepare nickel block, iron block and tungsten powder according to the ratio of Ni-17Fe-8W (at.%) alloy, then carry out surface treatment steps of nickel block and iron block, and place nickel block and iron block at a volume concentration of 95% or more. In the hydrochloric acid solution, the surface oxide and oil stain are removed by ultrasonic vibration, and then the nickel block and the iron block are placed in deionized water, and the hydrochloric acid solution remaining on the surface is removed by ultrasonic vibration, and then dried.

Next, the acid-washed nickel block and the iron block and the tungsten powder are placed in a crucible of a vacuum induction melting furnace and evacuated, and after the vacuum reaches 10 ^-3 torr or more, the temperature is raised to 1700 ° C, when the crucible is After the nickel block, the iron block and the tungsten powder are completely melted, the temperature is maintained at 1700 ° C for 5 minutes to ensure that the high melting point tungsten powder can be fully melted, and the molten metal soup composition is made uniform under the magnetic field provided by the induction coil.

Next, the molten Ni-17Fe-8W metal soup liquid was poured out from the crucible of the vacuum induction melting furnace, and the Ni-17Fe-8W metal soup liquid was sprayed by Ar gas to be atomized into a nickel alloy powder.

Next, the atomized nickel alloy powder was allowed to stand in the cavity for 4 hours to allow the nickel alloy powder to be naturally cooled. After the nickel alloy powder is cooled, a screening step is performed. In the present embodiment, the sieving step may use a sieving machine to remove the nickel alloy powder having a particle size of more than 200 μm or more, leaving a nickel alloy powder having a particle size of less than 200 μm, and storing it in a vacuum package.

The grain size of the nickel alloy powder is about 10 μm, and according to the actual analysis result of the energy dispersive spectrometer (EDS), the nickel alloy powder prepared by the invention is completely alloyed, and the composition is Ni-16.8Fe- 7.9W (at.%).

Finally, a hot pressing process is carried out, and after holding at a temperature of 1000 ° C for 2 hours, a fine and completely alloyed nickel alloy target can be obtained.

3 is a view showing the microstructure of a Ni-17Fe-8W nickel alloy target obtained by the manufacturing method of the present invention, wherein the scale of the lower right corner is 20 μm, as is clear from FIG. 3, the nickel alloy target The material not only has fine grains, but the distribution of the grains is also very uniform.

The method for manufacturing the nickel alloy target of the invention does not need to use the relatively expensive Ni powder and W powder as raw materials, does not need to use relatively expensive plasma sintering equipment for sintering of Ni and W powders, and does not need to be cooled. The rolling process and the recrystallization annealing treatment under the atmosphere protection can quickly and mass-prepare the nickel alloy target, so the manufacturing method is simple and the manufacturing time can be reduced. Furthermore, the nickel alloy target produced by the manufacturing method of the present invention has no component segregation, fine crystal grains, uniform crystal grain distribution and complete alloying, so that it has high sputtering quality.

The above embodiments are merely illustrative of the principles and effects of the invention and are not intended to limit the invention. Therefore, those skilled in the art can make modifications and changes to the above embodiments without departing from the spirit of the invention. The scope of the invention should be as set forth in the appended claims.

Figure 1 is a flow chart showing a method of manufacturing a nickel alloy target of the present invention;

2 is a view showing the microstructure of a Ni-8W nickel alloy target obtained by the production method of the present invention;

Fig. 3 is a view showing the microstructure of a Ni-17Fe-8W nickel alloy target obtained by the production method of the present invention.

(no component symbol description)

Claims (24)

A method for producing a nickel alloy target, comprising the steps of: (a) providing a nickel metal, at least a first alloying element, and a second alloying element, wherein the melting point of the second alloying element is lower than a melting point of the first alloying element; (b) performing a vacuum melting step to form an alloy solution; (c) atomizing the alloy solution to form a nickel alloy powder; (d) performing a sieving step to select a nickel alloy powder smaller than a set size And (e) forming and densifying the nickel alloy powder to form a nickel alloy target. The manufacturing method of claim 1, wherein the first alloying element in the form of flakes, powders or crumbs is used in the step (a). The manufacturing method of claim 1, wherein in the step (a), the first alloying element is selected from the group consisting of molybdenum (Mo), tungsten (W), tantalum (Ta), hafnium (Hf), yttrium (Ru), yttrium ( Re), zirconium (Zr) or niobium (Nb). The method of claim 1, wherein the step (a) further comprises the steps of: (a1) removing the nickel metal and oxides and contaminants on the surface of the first alloying element by using an acidic solution; (a2) removing An acidic solution on the surface of the nickel metal and the first alloying element; and (a3) drying the nickel metal and the first alloying element. The manufacturing method of claim 4, wherein in the step (a1), the volume concentration of the acidic solution is 95% or more. The production method of claim 4, wherein in the step (a1), the acidic solution is selected from hydrochloric acid or nitric acid. The manufacturing method of claim 4, wherein in the step (a2), the nickel metal and the acidic solution on the surface of the first alloying element are removed by deionized water. The manufacturing method of claim 3, wherein the weight percentage of the first alloying element is 5% to 20%. The manufacturing method of claim 8, wherein the first alloying element is a tungsten alloying element. The manufacturing method of claim 1, wherein the second alloying element is selected from the group consisting of iron (Fe), copper (Cu), or zinc (Zn). The manufacturing method of claim 1, wherein the nickel metal is more than 50% by weight, the first alloying element is 5% to 20% by weight, and the remaining weight percentage is the second alloying element content. The manufacturing method of claim 1, wherein the vacuum melting step is carried out in the vacuum induction melting furnace or the vacuum arc melting furnace in the step (b). The manufacturing method of claim 1, wherein in the step (b), the temperature of the vacuum melting is 1500 ° C to 1750 ° C. The manufacturing method of claim 1, wherein in the step (b), the vacuum degree of the vacuum melting is 10 ^-3 torr or more. The manufacturing method of claim 1, wherein in the step (c), the alloy solution is atomized by a high pressure inert gas by means of a spray. The method of claim 15, wherein the inert gas system is argon (Ar) or nitrogen (N ₂ ). The manufacturing method of claim 15, wherein the inert gas system in the step (c) The alloy solution was sprayed at a pressure of 1 to 5 MPa at a flow rate of 50 to 100 m/s. The manufacturing method of claim 1, wherein after the step (c), a cooling step is further included to cool the atomized nickel alloy powder. The manufacturing method of claim 18, wherein the atomized nickel alloy powder is cooled by a spray method using argon gas or nitrogen gas in the cooling step. The manufacturing method of claim 18, wherein the atomized nickel alloy powder is cooled by natural cooling in the cooling step. The manufacturing method of claim 1, wherein the set particle size of the nickel alloy powder sieved in the step (d) is less than 200 micrometers (μm). The manufacturing method of claim 1, wherein the forming and densifying steps are carried out in the step (e) by a hot press or a hot press. The manufacturing method of claim 1, wherein in the step (e), the molding and densification are carried out at a temperature of from 800 ° C to 1200 ° C, and the molding and densification is carried out for a period of from 0.5 to 3 hours. The manufacturing method of claim 1, which is applied to a film sputtering process in the magnetic recording industry, the photovoltaic industry, or the semiconductor industry.