Fe-ni alloy, its preparation method and application

Abstract

The present application relates to the technical field of Fe-Ni alloy, and particularly relates to a Fe-Ni alloy, a preparation method and application thereof. The Fe-Ni alloy is composed of the following elements according to the content of weight percentage: Ni: 30.0-35.0%, Co: 0.5-4.0%, Cu: 0.4-2.0%, Mn: 0.2-0.5%, Si: 0.2-0.5%, Ti: 0.1-0.3%, Ce: 0.01-0.1%, C: ≤0.05%, and the balance is Fe and other inevitable impurities. By adjusting the content of Ni and Co elements, designing multi-element alloying, and controlling the subsequent processing technology, the Fe-Ni alloy with a certain strength and lower production cost is obtained, and the thermal expansion coefficient of the Fe-Ni alloy is 3-6*10 ‑6 in the temperature range of -40-100 DEG C.

Description

Technical Field

[0001] This invention relates to the field of Fe-Ni alloy technology, and more particularly to an Fe-Ni alloy, its preparation method, and its applications. Background Technology

[0002] Fe-Ni alloys are classified into two types: low-expansion alloys (Invar alloys) and constant-expansion alloys (Kova alloys). They are characterized by adjustable coefficients of thermal expansion, high plasticity, and excellent stability. The 4J36 alloy contains 36% Ni and maintains its dimensions almost unchanged with temperature within a certain range of atmospheric temperatures. This type of Invar alloy has a coefficient of thermal expansion ≤1.6×10⁻⁶ between -20℃ and 100℃. -6 / K has a low coefficient of thermal expansion and is widely used in precision instrument components, aerospace molds, liquefied natural gas storage tanks, and shadow mask materials.

[0003] The coefficient of thermal expansion of 4J29 alloy is 4.6~5.2×10⁻⁶ in the temperature range of 20℃~400℃. -6 With a coefficient of thermal expansion of / K and good structural stability and processing performance, this constant expansion alloy has a relatively stable coefficient of thermal expansion in the room temperature range, making it an ideal material for sealing and precision components in industries such as semiconductors.

[0004] Filters used in electronic communications require Fe-Ni alloys to have a coefficient of thermal expansion of 3 to 6 × 10⁻⁶ within a temperature range of -40℃ to 100℃. -6 To meet the above requirements, commercial 4J29 alloy is generally selected between / K. However, the Co content in 4J29 alloy is 16.5%~20.0%. Since 2026, the price of Co has increased significantly, resulting in a sharp increase in the production cost of the alloy, which has limited the promotion and application of 4J29 alloy. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing an Fe-Ni alloy, its preparation method, and its applications. By adjusting the content of Ni and Co elements, employing multi-element alloying design, and controlling the hot rolling temperature, deformation amount, cooling method, and cold rolling deformation amount during subsequent processing, a thermal expansion coefficient of 3 to 6 × 10⁻⁶ is obtained in the temperature range of -40℃ to 100℃. -6 / K is a Fe-Ni alloy with certain strength and lower production cost, which meets the requirements for the production and application of filters for electronic communication.

[0006] The first objective of this invention is to provide a method for preparing an Fe-Ni alloy. The Fe-Ni alloy is composed of the following elements by weight percentage: Ni: 30.0~35.0%, Co: 0.5~1.0%, Cu: 0.4~2.0%, Mn: 0.2~0.5%, Si: 0.2~0.5%, Ti: 0.1~0.3%, Ce: 0.01~0.1%, C: ≤0.05%, with the balance being Fe and other unavoidable impurities; wherein the mass ratio of Ni to Co+Cu is 20~36; and the mass ratio of Mn+Si to Ce is not greater than 30. The total mass percentage of Ni, Co and Cu is ≤36%; The preparation method includes the following steps: S1: Casting Raw materials were prepared according to the composition of Fe-Ni alloy, and vacuum induction melting was carried out to obtain Fe-Ni alloy ingots. S2: Hot rolling treatment The Fe-Ni alloy ingot was hot-rolled at 950℃~1150℃ with a deformation of 40%~60% to obtain the hot-rolled Fe-Ni alloy. S3: Cold rolling process The Fe-Ni alloy is cold-rolled with a deformation of 30% to 60% to obtain the Fe-Ni alloy material.

[0007] Furthermore, in step S1, the melting temperature is 1550℃~1650℃, and the holding time is 60~120min.

[0008] Furthermore, the average coefficient of thermal expansion of the Fe-Ni alloy is controlled within the temperature range of -40℃ to 100℃, which is 3~6×10⁻⁶. -6 K -1 .

[0009] A second objective of this invention is to provide an Fe-Ni alloy prepared by the preparation method described above.

[0010] A third object of the present invention is to provide an application of the Fe-Ni alloy as described above, as a material for preparing filters for electronic communications.

[0011] The alloy described in this invention uses metal raw materials with a purity of not less than 99.9%.

[0012] The reasons for selecting diverse alloying elements in this invention are as follows: Ti: In the alloy of the present invention, Ti is a strong carbide forming element. When added together with C, it can significantly improve the strength of the alloy while maintaining thermal expansion properties. However, if the Ti content is too high, the thermal expansion coefficient of the alloy will increase. Therefore, the Ti content is selected to be within 0.3%.

[0013] Ce: In the alloy of this invention, the main function of adding Ce is to purify the microstructure and remove harmful impurities such as O and S. However, excessive addition is not conducive to the control of thermal expansion properties and the improvement of mechanical properties. Therefore, the Ce content is selected to be within 0.1%.

[0014] Si and Mn: In the alloy of this invention, Si and Mn play a similar role to Ce, serving as deoxidizers. However, excessive addition can lead to an increase in the coefficient of thermal expansion. Therefore, the content of Si and Mn is selected to be within 0.5% respectively.

[0015] Co: In the alloy of the present invention, the main role of Co is to increase the Curie temperature of the alloy, widen the low expansion temperature range, and reduce the coefficient of thermal expansion. However, when the Co content is too low, the effect of reducing the coefficient of thermal expansion is not obvious, and when it is too high, it will significantly increase the cost of the alloy. Therefore, the Co content is controlled at 0.5~4.0%.

[0016] Cu: In the alloy of the present invention, the role of Cu is to promote the alloy to maintain the FCC single phase and at the same time increase the Curie temperature of the alloy. However, too much Cu will increase the thermal expansion coefficient of the alloy. Therefore, the Cu content is selected to be 0.4~2.0%.

[0017] Compared with the prior art, the method for controlling the thermal expansion coefficient of Fe-Ni alloy based on multi-element alloying provided by the present invention has the following beneficial effects: 1) In the microalloying composition design of the Fe-Ni alloy of the present invention, on the one hand, by adding Si, Mn and Ce, the content of harmful impurities such as O and S is reduced, and the microstructure is purified; on the other hand, by adding a small amount of Co and Cu, the stability of the alloy's magnetic properties to temperature can be improved, and the saturation magnetization of the alloy can also be increased, thereby increasing the Curie temperature of the alloy and reducing the average thermal expansion coefficient from -40℃ to 100℃; at the same time, the addition of trace amounts of Ti and C elements enhances the strength of the alloy by forming carbides.

[0018] 2) In terms of process, based on the composition design, the Fe-Ni alloy of this invention controls the heating temperature, final rolling temperature, deformation amount, and cold deformation amount of the subsequent hot deformation to ensure that the final product has a coefficient of thermal expansion of 3 to 6 × 10⁻⁶ within the range of -40℃ to 100℃. -6 Between / K, it meets the needs of certain special service environments, such as the resonant rod of filters used in the field of electronic communication, etc. Compared with Invar alloys used in this field, it has a lower cost and has considerable economic benefits. Attached Figure Description

[0019] Figure 1 This is a metallographic diagram of Embodiment 1 of the present invention; Figure 2This is a metallographic diagram of Embodiment 2 of the present invention. Detailed Implementation

[0020] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0021] Example 1 This embodiment provides a method for preparing Fe-Ni alloys with controlled multi-element alloying, specifically including the following steps: Step 1: Melting: This invention uses a vacuum induction melting furnace for melting. The melting temperature is 1600℃, and the melting time is 90 minutes. The purity of the raw materials used for melting is 99.9%, and the mass ratio of each element in the raw materials is as follows: Ni: 32.00%, Co: 1.00%, Cu: 0.40%, Mn: 0.40%, Si: 0.20%, Ti: 0.20%, Ce: 0.02%, C: 0.05%, with the balance being Fe and unavoidable impurities. Before melting, the weighed raw materials are dried to remove excess moisture from their surface.

[0022] Step 2: Hot rolling: The smelted ingot is cut into 6mm plates, the plates are heated to 1150℃, the final rolling temperature is >950℃, and finally rolled into 3mm plates with a hot rolling deformation of 50%. The oxide layer on the surface is removed after hot rolling.

[0023] Step 3: Cold rolling: Cold rolling is carried out using conventional cold rolling technology, wherein the thickness deformation of the sheet is controlled within 50%.

[0024] Example 2 The difference between this embodiment and embodiment 1 is that the mass percentage of Co in this embodiment is 0.50%, while the rest is the same as in embodiment 1.

[0025] Comparative Example 1 The difference from Example 1 is that the mass percentage of each element is Ni: 36.00%, Co: 0.06%, Cu: 0.08%, Mn: 0.15%, Si: 0.12%, Ti: 0.05%, Ce: 0.02%, C: 0.05%, with the balance being Fe and unavoidable impurities.

[0026] Comparative Example 2 The difference from Example 1 is that the mass percentage of each element is Ni: 33.00%, Co: 3.43%, Cu: 0.005%, Mn: 0.17%, Si: 0.06%, Ti: 0.01%, Ce: 0.02%, C: 0.002%, with the balance being Fe and unavoidable impurities.

[0027] Comparative Example 3 The difference from Example 1 is that the mass percentage of each element is Ni: 31.00%, Co: 0.01%, Cu: 0.01%, Mn: 0.40%, Si: 0.20%, Ti: 0.01%, Ce: 0.02%, C: 0.05%, with the balance being Fe and unavoidable impurities.

[0028] Comparative Example 4 The difference from Example 1 is that the mass percentage of each element is Ni: 30.00%, Co: 0.01%, Cu: 0.01%, Mn: 0.20%, Si: 0.01%, Ti: 0.20%, Ce: 0.001%, C: 0.05%, with the balance being Fe and unavoidable impurities.

[0029] The alloy compositions used in each embodiment and comparative example are shown in Table 1.

[0030] Table 1

[0031] In Table 1, Examples 1-2 conform to the Fe-Ni alloy chemical composition described in this invention; Comparative Examples 1-2 do not conform to the Fe-Ni alloy chemical composition described in this invention. Specifically, in Comparative Example 1, the total mass percentage of Ni, Co, and Cu is greater than 36%, i.e., Ni+Co+Cu>36%; in Comparative Example 2, the mass percentage of Ni, Co, and Cu is less than 20%, i.e., Ni / (Co+Cu)<20; in Comparative Example 3, the mass percentage of Ni, Co, and Cu is greater than 36%, i.e., Ni / (Co+Cu)>36; in Comparative Example 4, Ni / (Co+Cu)>36, and the mass percentage of Mn+Si and Ce is greater than 30%, i.e., (Mn+Si) / Ce>30.

[0032] The thermal expansion properties of the samples were tested using a TMA402 F3 thermomechanical analyzer in accordance with the national standard GB / T 4339-2008 "Determination of characteristic parameters of thermal expansion of metals". The average linear expansion coefficients of each example and comparative example at -40℃~100℃ or 25℃~100℃ were obtained, and the results are shown in Table 2.

[0033] Table 2

[0034] As can be seen from Table 2, the average coefficients of thermal expansion of Examples 1 and 2, which conform to the chemical composition of the Fe-Ni alloy described in this invention, are both 3~6×10⁻⁶ at -40℃~100℃ and 25℃~100℃. -6 / K, while the average coefficients of thermal expansion of Comparative Examples 1 to 4 deviated by 3 to 6 × 10⁻⁶ at -40℃ to 100℃ or 25℃ to 100℃. -6 The range is / K.

[0035] Based on the above experimental results, the method for controlling the thermal expansion coefficient of Fe-Ni alloys based on multi-element alloying provided by this invention can effectively control the average thermal expansion coefficient of Fe-Ni alloys within the range of 3~6×10⁻⁶℃ from -40℃ to 100℃. -6 K -1 Compared with the prior art, the advantages of this invention are that it reduces the content of Co and Cu, and eliminates the heat treatment process, resulting in a simple production process and low alloy cost.

[0036] Figure 1 , 2 These are metallographic images of the plates prepared in Examples 1 and 2 of this invention. It can be seen from the images that the microstructure of the cold-rolled alloy is uniformly distributed. The Co contents of Examples 1 and 2 are 1.00% and 0.50%, respectively. Metallographic observation revealed that in the alloy of Example 1 with higher Co content, the grain size is smaller and the number of deformation bands and deformation twins is less.

[0037] For any points not covered above, existing technologies shall apply.

[0038] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the direction of the invention or exceeding the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an Fe-Ni alloy, characterized in that, The chemical composition of Fe-Ni alloys, by weight percentage, consists of the following elements. Composition: Ni: 30.0~35.0%, Co: 0.5~1.0%, Cu: 0.4~2.0%, Mn: 0.2~0.5%, Si: 0.2~0.5%, Ti: 0.1~0.3%, Ce: 0.01~0.1%, C: ≤0.05%, with the balance being Fe and other unavoidable impurities; wherein the mass ratio of Ni to Co+Cu is 20~36; the mass ratio of Mn+Si to Ce is not greater than 30; The total mass percentage of Ni, Co and Cu is ≤36%; The preparation method includes the following steps: S1: Casting Prepare raw materials according to the composition of Fe-Ni alloy, perform vacuum melting, and obtain Fe-Ni alloy ingots; S2: Hot rolling treatment The Fe-Ni alloy ingot was hot-rolled at 950℃~1150℃ with a deformation of 40%~60% to obtain the hot-rolled Fe-Ni alloy. S3: Cold rolling process The Fe-Ni alloy is cold-rolled with a deformation of 30% to 60% to obtain the Fe-Ni alloy.

2. The preparation method according to claim 1, characterized in that, In step S1, the melting temperature is 1550℃~1650℃, and the holding time is 60~120 min.

3. The preparation method according to claim 1, characterized in that, The average coefficient of thermal expansion of the Fe-Ni alloy is controlled within 3×10⁻⁴℃ in the temperature range of -40℃ to 100℃. -6 K -1 ~6×10 -6 K -1 .

4. An Fe-Ni alloy prepared by the preparation method according to any one of claims 1-3.

5. An application of the Fe-Ni alloy as described in claim 4, characterized in that, It is used as a material for manufacturing filters for electronic communications.

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