KR102289441B1 - Ni-based amorphous alloy and preparing method thereof - Google Patents

Abstract

The present invention relates to a Ni-based amorphous alloy. The present invention includes Ni, Ta and Nb, and _{is expressed by the compositional formula Ni 100-ab} Ta _a Nb _b , wherein a and b are atomic% of Ta and Nb, respectively, wherein a is 1≤a≤30, and b provides a Ni-based amorphous alloy, characterized in that 5≤b≤40.

Description

Ni-based amorphous alloy and its manufacturing method {Ni-based amorphous alloy and preparing method thereof}

The present invention relates to a Ni-based amorphous alloy, and to a Ni-based amorphous alloy and a manufacturing method thereof.

Recently, interest in a power plant using biomass as a new and renewable energy power plant for reducing carbon dioxide has recently increased. However, unlike conventional boilers that use coal as fuel, biomass power generation has a large corrosion problem due to chlorides emitted during combustion, so it is necessary to lower the temperature to 350 to 550 ° C., so additional facilities are required. Or there is a problem that the power generation device must be operated under extremely limited conditions. Accordingly, research is being conducted to prevent damage to the equipment of biomass power generation by using a metal alloy capable of minimizing corrosion.

In general, most metal alloys form crystalline phases in which the arrangement of atoms is regular when solidifying from a liquid phase. However, if the cooling rate during solidification is sufficiently large above the critical value to limit the nucleation and growth of the crystal phase, the irregular atomic structure of the liquid phase may be maintained as it is. Such an alloy is generally referred to as an amorphous alloy or a metallic glass.

Amorphous alloys exhibit homogeneous isotropic properties without anisotropy, grain boundaries, or surface defect segregation, etc., which are seen in general crystalline alloys, and have excellent mechanical strength because there is no crystallographic anisotropy. In addition, it has excellent corrosion resistance due to its uniform structure and composition, so it is suitable for use in extreme environments.

Furthermore, nanocrystalline alloy has a similar atomic arrangement to molten metal and has a very small nanometer-sized grain structure, so it exhibits superior strength, high corrosion resistance and excellent wear resistance compared to general crystalline alloys.

In the present invention, an amorphous alloy material is proposed to solve the corrosion problem of a power plant using biomass.

One object of the present invention is to provide a Ni-based amorphous alloy having excellent durability against high temperature/corrosion/wear environments and improved mechanical strength.

Another object of the present invention is to provide a biomass plant to which a Ni-based amorphous alloy having excellent durability against high temperature/corrosive/abrasion environments and improved mechanical strength is applied.

The present invention relates to a Ni-based amorphous alloy. The present invention includes Ni, Ta and Nb, and _{is expressed by the compositional formula Ni 100-ab} Ta _a Nb _b , wherein a and b are atomic% of Ta and Nb, respectively, wherein a is 1≤a≤30, and b provides a Ni-based amorphous alloy, characterized in that 5≤b≤40.

In an embodiment, the glass transition temperature (Tg) of the Ni-based amorphous alloy is characterized in that 900 to 1,000 ℃.

In an embodiment, the Ni-based amorphous alloy is characterized in that it further comprises Mo.

In an embodiment, the composition formula of the Ni-based amorphous alloy containing Mo _{is expressed as Ni 100-ab} Ta _a Nb _{b Mo c} , wherein c is atomic% of Mo, and c is 1≤c≤15 characterized.

In an embodiment, the Ni-based amorphous alloy is an amorphous matrix composite in which a nanocrystalline phase is precipitated.

In an embodiment, the Ni-based amorphous alloy is characterized in that it is formed in a ribbon shape.

In an embodiment, a biomass plant coated with the Ni-based amorphous alloy is presented.

In an embodiment, it is characterized in that the superheater conduit of the biomass plant is coated with the Ni-based amorphous alloy.

In addition, in the manufacturing method of the Ni-based amorphous alloy, Ni, Ta, and the steps of preparing a mother alloy by dissolving the Ni-based amorphous alloy material containing Nb; and forming the mother alloy into a ribbon shape by melt spinning, wherein the mother alloy is _{represented by a compositional formula Ni 100-ab} Ta a Nb _b , wherein a and b are atoms of Ta and Nb, respectively %, wherein a is 1≤a≤30, and b is 5≤b≤40.

In an embodiment, further comprising a heat treatment step, the heat treatment step is characterized in that it is performed in a temperature range of 730 to 800K to precipitate a nanocrystalline phase.

In an embodiment, the Ni-based amorphous alloy material is characterized in that it further comprises Mo.

In an embodiment, the composition formula of the mother alloy containing Mo _{is expressed as Ni 100-ab} Ta _a Nb _{b Mo c} , wherein c is atomic% of Mo, and c is 1≤c≤15 do it with

The Ni-based amorphous alloy according to the present invention may form a nanometer-sized grain structure to improve durability and mechanical strength against high temperature/corrosive/abrasion environments.

In addition, by applying a Ni-based amorphous alloy with improved durability and mechanical strength to high temperature/corrosion/abrasion environments to parts constituting a biomass plant operating at high temperature, corrosion resistance to high temperature oxidizing atmosphere and aqueous solution is improved. There is an effect that can protect the biomass plant in the operating environment of

In addition, the Ni-based amorphous alloy according to the present invention, including Nb, forms a film on the parts constituting a biomass plant operating at a high temperature by a thermal spraying process or a welding process, thereby improving adhesion on the base material.

1 is a real image of the Ni-based amorphous alloy of the present invention.
2 is an XRD graph of the Ni-based amorphous alloy prepared in Examples.
3 is a differential thermal analysis (DTA) graph of the Ni-based amorphous alloy prepared in Examples.
4 is a graph showing the weight loss rate (weight loss (%)) of the Ni-based amorphous alloy prepared in Examples.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and overlapping descriptions thereof will be omitted. In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , should be understood to include equivalents or substitutes.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as "comprises" or "have" are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

The present invention relates to a Ni-based amorphous alloy.

In an embodiment of the present invention, the Ni-based amorphous alloy may include Ni (nickel), Ta (tantalum), and Nb (niobium). Furthermore, the composition formula of the Ni-based amorphous alloy is expressed as _{Ni 100-ab} Ta _a Nb _{b .} Here, a and b are atomic percent of Ta and Nb, respectively, a may be 1≤a≤30, and b may be 5≤b≤40.

The Ni-based amorphous alloy of the present invention exhibits a homogeneous isotropic property without anisotropy, grain boundary, surface defect segregation, and the like, which appears in general crystalline structure alloys, and exhibits excellent mechanical strength because there is no crystallographic anisotropy. In addition, it has excellent corrosion resistance due to its uniform structure and composition, so it is suitable for use in extreme environments.

In detail, the Ni is a component constituting a matrix, and when Ni corresponds to 100-ab atomic %, the provision of a Ni-based amorphous alloy having high corrosion resistance and excellent amorphous forming ability to be achieved in the present invention is possible.

Ta serves to further improve corrosion resistance. As described above, Ta is preferably 1 to 30 atomic%. When the content of Ta is added to less than 1 atomic %, it is difficult to expect the effect of improving the corrosion resistance. On the other hand, when the content of Ta is added in excess of 30 atomic%, it is difficult to expect an amorphous shape.

On the other hand, Nb may serve to secure the formation of an amorphous phase and improve oxidation resistance. In addition, the Ni-based amorphous alloy of the present invention, including Nb, has an advantage in that wettability is improved and adhesion is greatly improved. Furthermore, Nb is easily combined with oxygen in Ni-based amorphous alloys _{to form oxides such as NbO 2} , Nb ₂ O ₅ . These niobium oxides are chromium oxides formed by Cr contained in the conventional Ni alloy composition with improved corrosion resistance. Compared to that, the oxidation resistance is very good.

As described above, Nb is preferably 5 to 40 atomic %. When the content of Nb is added to less than 5 atomic %, it is difficult to expect an effect of improving wettability and oxidation resistance. On the other hand, when the content of Nb is added in excess of 40 atomic%, it is difficult to expect an amorphous shape.

The amorphous shape of the Ni amorphous alloy of the present invention can be crystallized by nucleation and growth. Therefore, the crystallization behavior can be directly related to controlling the growth conditions of the crystal phase. In addition, controlling the crystallization of the amorphous alloy can be applied to obtain an amorphous matrix composite in which a nanometer-sized crystalline phase is partially crystallized in an amorphous matrix. The amorphous matrix composite in which the nanocrystalline phase is precipitated has excellent mechanical properties and excellent magnetic properties. can

The Ni-based amorphous alloy according to an embodiment of the present invention may have a glass transition temperature (Tg) in the range of 900 to 1,000 ℃. Accordingly, the Ni-based amorphous alloy according to the present invention can maintain a stable state without physical/chemical deformation even when used in a high temperature environment of about 900°C or higher.

In one embodiment of the present invention, the Ni-based amorphous alloy may further include Mo (molybdenum). The Ni-based amorphous alloy containing Mo may have improved amorphous formation ability. In addition, Mo exhibits a remarkable effect by co-addition with Ta and Nb under the conditions of sulfuric acid corrosion resistance or hydrochloric acid corrosion resistance of Ni-based amorphous alloys. By adding Mo to the Ni-based amorphous alloy, the Ni-based amorphous alloy may exhibit corrosion resistance equivalent to or higher than Stellite No. 1 and No. 6 of the cobalt-based alloy.

In detail, since Mo is added to the Ni-based amorphous alloy, the compositional formula of the Ni-based amorphous alloy may be expressed as _{Ni 100-ab} Ta _a Nb _b Mo _{c .} a and b for the atomic % of Ta and Nb follow the description above. c to atomic % of Mo may be in the range of 1≤c≤15. Atomic % of Mo may exhibit sufficient corrosion resistance in the range of 1 to 15. In particular, when Mo is 1 atomic% or more, the corrosion resistance to the sulfur phase exceeds the corrosion resistance of the stellite. On the other hand, Mo is an expensive metal, and when it is 15 atomic% or more, there is a problem in that there is no significant improvement in performance due to excessive addition, as well as an increase in cost.

In addition, the Ni-based amorphous alloy according to an embodiment of the present invention may satisfy the following relational expression 1 with respect to the corrosion test. In the corrosion test, the Ni-based amorphous alloy of the present invention is immersed in a 10% hydrochloric acid solution, left at room temperature for 4 days, and then recovered and the weight thereof is measured.

[Relational Expression 1]

1 ≤((w ₀ -w ₁ )/w ₀ )*100≤5

(w ₀ is the weight of the Ni-based amorphous alloy before performing the corrosion test, w ₁ is the weight measured after performing the corrosion test)

That is, the Ni-based amorphous alloy of the present invention has a weight change of 1 to 5 wt% when the above-described corrosion test is performed. The conditions of the corrosion test are harsher than the environment in which the actual Ni-based amorphous alloy is applied. It may have improved corrosion resistance compared to the alloy-based alloy.

1 is a real image of the Ni-based amorphous alloy of the present invention.

Referring to FIG. 1 , the Ni-based amorphous alloy of the present invention may be formed into a ribbon shape. Furthermore, the Ni-based amorphous alloy of the present invention can be applied to a biomass plant that needs to minimize corrosion by discharging corrosive substances such as chloride during combustion. That is, the present invention may include a biomass power plant in which the above-described Ni-based amorphous alloy is film-treated.

In detail, the Ni-based amorphous alloy of the present invention, including Nb, forms a film on the parts constituting a biomass plant operating at a high temperature by a thermal spraying process or a welding process, resulting in an effect of improving adhesion on the base material. .

In addition, the Ni-based amorphous alloy of the present invention has improved durability and mechanical strength against high-temperature/corrosive/abrasion environments to prevent damage to the biomass plant in a high-temperature oxidation atmosphere and aqueous solution environment in which the biomass plant operates. can protect

In particular, the present invention may include a super heater conduit for a biomass power plant in which the above-described Ni-based amorphous alloy is coated. The conduit or protective tube of the superheater for a biomass power plant is used in severe abrasion conditions, so high temperature abrasion is severe. Therefore, by using the Ni-based amorphous alloy of the present invention to form a coating layer on the conduit of the superheater by a thermal spraying process or a welding process, there is an effect that can protect the biomass plant by solving the corrosion problem under severe corrosion conditions.

The present invention may include a method for producing a Ni-based amorphous alloy.

In detail, the manufacturing method of the Ni-based amorphous alloy comprises the steps of: preparing a mother alloy by dissolving a Ni-based amorphous alloy material containing Ni, Ta and Nb; and forming the mother alloy into a ribbon shape by melt spinning.

At this time, the master alloy is _{expressed by the composition formula Ni 100-ab} Ta _a Nb _b , which follows the above description. (The a and b are atomic% of Ta and Nb, respectively, wherein a is 1≤a≤30, and b is 5≤b≤40) Specifically, the master alloy manufacturing step is the above-described Ni-based amorphous alloy A master alloy can be prepared by dissolving a material (or raw material) containing a component of The molten metal for forming the master alloy may be prepared by charging the Ni-based amorphous alloy material into the melting crucible and increasing the temperature inside the melting crucible to 1,500° C. or higher.

Furthermore, in the forming step, the mother alloy may be manufactured in a ribbon form through a rapid solidification method (melt spinning). Accordingly, the Ni-based amorphous alloy may have a ribbon shape. The rapid solidification method is performed at 2,000 to 4,000 rpm, and a ribbon-shaped Ni-based amorphous alloy having an average width of 1 to 20 mm can be prepared.

In addition, the manufacturing method of the Ni-based amorphous alloy of the present invention may further include a heat treatment step. Through the heat treatment step, nanocrystals in the Ni-based amorphous alloy may be precipitated. The heat treatment may be performed in a temperature range of 730 to 800K. When the Ni-based amorphous alloy has nanocrystals, corrosion resistance properties may be further improved. That is, the Ni-based amorphous alloy having nanocrystals may reach an effect of increasing corrosion resistance under a high concentration of hydrochloric acid.

In addition, the mother alloy of the Ni-based amorphous alloy may further include Mo. Accordingly, the compositional formula of the mother alloy may be expressed as _{Ni 100-ab} Ta _a Nb _b Mo _{c .} a and b for the atomic % of Ta and Nb follow the description above. c for atomic% of Mo may be in the range of 1≤c≤15, and the description of Mo follows the above description.

Hereinafter, embodiments for specific description of the present invention are presented. However, the present invention is not limited to the following examples.

[Example]

A master alloy is prepared by dissolving the alloy having the at% composition of Table 1 through a vacuum arc melting furnace, and the master alloy is subjected to rapid solidification (melt spinning) at a rotation speed of 3,000 rpm to form a ribbon having a width of 5 to 20 mm. A Ni-based amorphous alloy was prepared.

division Ta Nb Mo Ni Ni No.1 20 10 15 balance Ni No.2 2 7 15 balance

1 is a real image of the Ni-based amorphous alloy of the present invention.

1, it can be seen that the Ni-based amorphous alloy according to the embodiment of the present invention is in the form of a ribbon having a thin thickness and a wide width.

2 is an XRD graph of the Ni-based amorphous alloy prepared in Examples.

As shown in FIG. 2, it can be seen that the Ni-based amorphous alloy according to the embodiment has a typical halo pattern of amorphous as a result of XRD analysis, and when it is judged that there is no crystalline phase peak, it can be seen that all of them are 100% amorphous.

3 is a differential thermal analysis (DTA) graph of the Ni-based amorphous alloy prepared in Examples. As described above, in order to use the superheater conduit for a biomass plant, it is important that the manufactured alloy maintain a stable state without deformation in a high temperature environment of about 900° C. or higher. Accordingly, differential thermal analysis was performed to confirm the high-temperature characteristics of the Ni-based amorphous alloy prepared in the above Examples.

As a result, it can be seen that the glass transition temperature (Tg) of the Ni-based amorphous alloy shown as Ni No. 1 is about 923 ° C., and the glass transition temperature (Tg) of the Ni-based amorphous alloy shown as Ni No. 2 is It can be seen that the temperature is about 955°C. That is, it can be seen that the Ni-based amorphous alloy of the present invention has properties suitable for protecting the biomass plant by being applied to the biomass plant.

4 is a graph showing the weight loss rate (weight loss (%)) of the Ni-based amorphous alloy prepared in Examples. In detail, the weight reduction rate was measured after cutting the Ni-based amorphous alloy to a size of 5 mm in width, and is defined by Equation 1 below.

[Equation 1]

Weight loss rate (%) = ((w ₀ -w ₁ )/w ₀ )*100

(In Equation 1, w ₀ is the weight of the Ni-based amorphous alloy used in the corrosion test, w ₁ is the weight of the Ni-based amorphous alloy measured after performing the corrosion test, and the corrosion test is the Ni-based amorphous alloy After immersing in 10% hydrochloric acid solution and leaving it at room temperature for up to 100 days, the corroded Ni-based amorphous alloy is recovered and its weight is measured.)

Referring to FIG. 4 , it can be seen that the weight reduction rate (%) is less than 5% even after being immersed in a 10% hydrochloric acid solution and left at room temperature for 100 days. The conditions of the corrosion test are harsher than the environment in which the actual Ni-based amorphous alloy is applied. It may have improved corrosion resistance compared to the alloy-based alloy.

It is apparent to those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit and essential characteristics of the present invention.

In addition, the above detailed description should not be construed as restrictive in all respects but as exemplary. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention.

Claims (12)

In the Ni-based amorphous alloy containing Ni, Ta and Nb,
It is expressed by the composition formula Ni _100-ab Ta _a Nb _{b ,}
wherein a and b are atomic % of Ta and Nb, respectively,
wherein a is 1≤a≤30,
wherein b is 5≤b≤40,
The Ni-based amorphous alloy further comprises Mo,
The composition formula of the Ni-based amorphous alloy containing Mo is expressed as _{Ni 100-ab} Ta _a Nb _{b Mo c ,}
Wherein c is atomic% of Mo,
Wherein c is 1≤c≤15,
The Ni-based amorphous alloy is a Ni-based amorphous alloy, characterized in that the nanocrystalline phase is precipitated amorphous matrix composite material. According to claim 1,
Ni-based amorphous alloy, characterized in that the glass transition temperature (Tg) of the Ni-based amorphous alloy is 900 to 1,000 ℃. delete delete delete According to claim 1,
The Ni-based amorphous alloy is Ni-based amorphous alloy, characterized in that formed in a ribbon shape. In the biomass plant film-treated with Ni-based amorphous alloy,
The Ni-based amorphous alloy includes Ni, Ta and Nb,
It is expressed by the composition formula Ni _100-ab Ta _a Nb _{b ,}
wherein a and b are atomic % of Ta and Nb, respectively,
wherein a is 1≤a≤30,
wherein b is 5≤b≤40,
The Ni-based amorphous alloy further comprises Mo,
The composition formula of the Ni-based amorphous alloy containing Mo is expressed as _{Ni 100-ab} Ta _a Nb _{b Mo c ,}
Wherein c is atomic% of Mo,
Wherein c is 1≤c≤15,
The Ni-based amorphous alloy is characterized in that the nanocrystalline phase is precipitated amorphous matrix composite material,
biomass plant. 8. The method of claim 7,
A biomass plant, characterized in that the superheater conduit of the biomass plant is coated with the Ni-based amorphous alloy. In the manufacturing method of a Ni-based amorphous alloy,
preparing a master alloy by dissolving a Ni-based amorphous alloy material containing Ni, Ta and Nb;
forming the mother alloy into a ribbon shape by a rapid solidification method (melt spinning); and
To include; heat-treating the mother alloy molded in the ribbon shape;
The heat treatment step is performed in a temperature range of 730 to 800K to precipitate a nanocrystalline phase,
The master alloy is represented by the _{composition formula Ni 100-ab} Ta _a Nb _{b ,}
wherein a and b are atomic % of Ta and Nb, respectively,
wherein a is 1≤a≤30,
wherein b is 5≤b≤40,
The Ni-based amorphous alloy material further comprises Mo,
The Mo is dissolved together with Ni, Ta and Nb during the step of preparing the master alloy to prepare a mother alloy,
The composition formula of the mother alloy containing Mo is expressed as _{Ni 100-ab} Ta _a Nb _{b Mo c ,}
Wherein c is atomic% of Mo,
Wherein c is a method for producing a Ni-based amorphous alloy, characterized in that 1≤c≤15. delete delete delete

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