Five-membered Cr-(Al, Bi, In)-B MAB phase solid solution and preparation method thereof
By hot-dip plating of Al-10 In-5Si alloy and corrosion of BiCl3 molten salt by Fe-Cr-B cast steel, a five-membered Cr-(Al, Bi, In)-B MAB phase solid solution was prepared, which solved the problem of difficulty in preparing MAB phases containing In and Bi in the prior art, and achieved In whisker growth of Cr-(Al, In)-B MAB phase, expanding the types and preparation methods of MAB phases.
Patent Information
- Application Number
- CN202510184710.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-19
- Publication Date
- 2025-05-23
AI Technical Summary
It is difficult to prepare MAB phases containing In and Bi, especially five-membered Cr-(Al, Bi, In)-B MAB phase solid solution, and whether the Cr-Al-B MAB phase can self-grow In whiskers has not been determined.
After hot-dip plating of Al-10In-5Si alloy by Fe-Cr-B cast steel and diffused heat treatment, the solid solution of Cr-(Al, In)-B and Cr-(Al, Bi, In)-B were used to corrosion using BiCl3 molten salt to achieve the preparation of Cr-(Al, In)-B and Cr-(Al, Bi, In)-B MAB phases.
The five-membered Cr-(Al, Bi, In)-B MAB phase solid solution was prepared for the first time, expanding the types of MAB phase and its preparation method. It was found that the Cr-(Al, In)-B MAB phase solid solution will spontaneously grow In whiskers, while the Cr-(Al, Bi, In)-B MAB phase solid solution will not grow whiskers.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of new materials, and particularly relates to a quinary Cr-(Al, Bi, In)-B MAB phase solid solution and a preparation method thereof. Background Art
[0002] MAB phase is a type of ternary transition metal boron compound with layered atomic arrangement, where M is a transition metal element, A is a 13-16 group element, generally Al, and B is boron. The concept of MAB phase was defined by Ade et al. in 2015. It is similar to the much-studied MAX phase (X is C, N), but its structure and composition are more complex than the MAX phase. There are many reports on MAX phases containing multiple elements at the A position, such as Tian et al. using pressureless sintering to prepare Ti 3 (Sn, Al)C 2 MAX phase solid solution, Horlait et al. first synthesized Zr using powder metallurgy 2 (Al, Bi)C MAX phase solid solution, but there are few reports on MAX / MAB phases containing In at the A site. The synthesized MAX phase containing In at the A site mainly contains Zr 2 InC、Ti 2 InC et al., Wang et al. first synthesized Ti using a pressureless sintering method in 2019 2 IB 2 Although there are reports of MAX / MAB phase containing both In and Bi at the A site, there are no reports of MAX / MAB phase containing both In and Bi at the A site. Even looking at the entire metal compound, there are very few ternary compounds containing both In and Bi.
[0003] The phenomenon of spontaneous growth of Sn whiskers in Sn coatings has been discovered for nearly 60 years, but the spontaneous growth of A-site whiskers in MAX phase has only been discovered for about 20 years. The spontaneous growth of MAB phase whiskers is extremely rare. Tang et al. reported in 2023 that Ti was prepared by pressureless sintering + ball milling + cold pressing + artificial aging (24h). 2 IB 2 In whiskers grown from the MAB phase. However, the Ti synthesized for the first time by Wang et al. in 2019 using a pressureless sintering method 2 IB 2 However, no whisker growth was observed in the MAB phase. Therefore, it is speculated that the ball milling + cold pressing + artificial aging process is the main process of the Ti 2 IB 2 MAB phase is an essential step in the growth of In whiskers.
[0004] The inventors found in their previous studies that when hot-dip aluminum is applied to Fe-Cr-B cast steel, FeAl 3The Cr-Al-B MAB phase is a periodic lamellar structure (PLS) composed of alternating Cr-Al-B and Cr-Al-B MAB phases, and elements such as Sn in the aluminum liquid will significantly affect the composition of the Cr-Al-B MAB phase and form MAB phase solid solutions such as Cr-(Al, Sn)-B. In addition, when the Cr-Al-B MAB phase reacts with SnCl2 molten salt, MAB phase solid solutions such as Cr-(Al, Sn)-B will also be generated. Interestingly, these Cr-(Al,Sn)-B MAB phase solid solutions will spontaneously grow Sn whiskers. However, it is still unknown whether the Cr-Al-B MAB phase can spontaneously grow In whiskers, and there are few reports of MAB phases containing both In and Bi at the A site. Summary of the invention
[0005] The technical problem to be solved by the present invention is to provide a five-component Cr-(Al, Bi, In)-B MAB phase solid solution and a preparation method thereof. The five-component Cr-(Al, Bi, In)-B MAB phase solid solution is prepared for the first time, and the types of MAB phases and preparation methods thereof are expanded.
[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a five-component Cr-(Al, Bi, In)-BMAB phase solid solution, in which the Al atoms at the A position in the Cr-Al-B MAB phase are partially replaced by Bi and In to form a solid solution containing Al, Bi and In at the same time, and the number of Bi atoms is greater than that of In.
[0007] The present invention also provides a method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution, comprising the following steps: S1, hot dip aluminum: Containing borides (Cr, Fe) 2 The Fe-Cr-B cast steel of B is hot-dip plated in an aluminum alloy melt, the aluminum alloy is Al-10In-5Si alloy, the aluminum alloy melt temperature is 700-750°C, the hot-dip plating time is 25-30 minutes, and after reaching the set time, it is taken out and air-cooled to room temperature; S2. Diffusion heat treatment: The sample prepared in step S1 is placed in a muffle furnace for diffusion heat treatment, kept at 750-800°C for 55-60 minutes, and cooled to room temperature with the furnace after reaching the set time; S3、BiCl 3 Molten salt corrosion: The sample prepared in step S2 is immersed in BiCl 3 Soak in the molten salt solution for 55 to 60 minutes, take it out after the set time is reached, and cool it to room temperature.
[0008] In a preferred embodiment, in step S1, during the hot-dip plating of Al-10In-5Si alloy, a periodic lamellar structure containing a Cr-Al-B MAB phase is first generated, and then the In atoms in the Al-10In-5Si alloy partially replace the Al atoms in the Cr-Al-B MAB phase to form a quaternary Cr-(Al, In)-B MAB phase solid solution; in step S3, the quaternary Cr-(Al, In)-B MAB phase solid solution is formed in the presence of BiCl 3 During molten salt corrosion, Bi 3+ Partially replace Al and form a quinary Cr-(Al, Bi,In)-B MAB phase solid solution.
[0009] In a preferred embodiment, in step S1, the Cr-(Al, In)-BMAB phase solid solution formed after hot-dip plating of Al-10In-5Si alloy will spontaneously grow In whiskers.
[0010] In a preferred embodiment, in step S1, when hot-dip plating Al-10In-5Si alloy is performed, the In atoms in the aluminum alloy partially replace the Al atoms in the Cr-Al-B MAB phase and also form a nano-sized pure In phase on the grain boundary of the Cr-Al-B MAB phase.
[0011] In a preferred embodiment, it is characterized in that the pure In phase formed on the grain boundary during hot-dip aluminum plating is 3 During molten salt corrosion, it is replaced by pure Bi phase.
[0012] In a preferred embodiment, in step S3, BiCl 3 During molten salt corrosion, the quinary Cr-(Al, Bi, In)-B MAB phase solid solution is obtained through the following reaction formula: Cr-(Al, In)-B MAB phase+BiCl 3 →Cr-(Al, Bi, In)-B MAB phase+Bi+AlCl 3 ↑+InCl 3 ↑.
[0013] In a preferred embodiment, in step S3, BiCl 3 During molten salt corrosion, some Al and In atoms in the Cr-(Al, In)-B MAB phase solid solution formed during hot-dip aluminum plating in the corrosion zone will turn into gas due to the generation of corresponding volatile chlorides, making the number of Bi atoms in the generated Cr-(Al, Bi, In)-B MAB phase solid solution greater than that of In; BiCl 3After molten salt corrosion, the Cr-(Al, In)-B MAB phase solid solution formed during hot-dip aluminum plating in the non-corrosion zone will accelerate the growth of In whiskers.
[0014] In a preferred embodiment, the In whiskers only grow in the Cr-(Al, In)-B MAB phase solid solution region, and do not grow in the Cr-(Al, Bi, In)-B MAB phase solid solution region.
[0015] In a preferred embodiment, in step S1, the periodic lamellar structure containing the Cr-Al-B MAB phase is formed by FeAl 3 Alternating composition of Cr-Al-B MAB, hot-dip Al-In-Si alloy and BiCl 3 In molten salt corrosion, alloying elements In and Bi have an influence on the FeAl 3 No impact.
[0016] The present invention provides a quinary Cr-(Al, Bi, In)-B MAB phase solid solution and a preparation method thereof, which have the following beneficial effects: 1. Hot dip coating of Fe-Cr-B cast steel with Al-In-Si alloy and low temperature BiCl 3 By molten salt corrosion, Cr-(Al, In)-B and Cr-(Al, Bi, In)-B MAB phase solid solutions were prepared for the first time, expanding the types of MAB phases and their preparation methods.
[0017] 2. The Cr-(Al, In)-BMAB phase solid solution will spontaneously grow In whiskers, while the Cr-(Al, Bi, In)-B MAB phase solid solution will not grow whiskers. This not only enriches the types of whisker growth, but also discovers a method to inhibit whisker growth.
[0018] 3. BiCl 3 During molten salt corrosion, the temperature is low, it is very easy to achieve and the operation is simple.
[0019] 4. The Si element improves the high-temperature oxidation resistance of the periodic lamellar structure coating, but has no effect on the growth of Cr-(Al, In)-B and Cr-(Al, Bi, In)-B MAB phase solid solutions and In whiskers. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 This is a cross-sectional microstructure diagram of the Fe-Cr-B cast steel prepared in Example 1 after hot-dip plating with Al-10In-5Si alloy and diffusion heat treatment; Figure 2Cr element distribution diagram of the cross section of the Fe-Cr-B cast steel prepared in Example 1 after hot-dip plating of Al-10In-5Si alloy and diffusion heat treatment; Figure 3 This is the In element distribution diagram of the cross section of the Fe-Cr-B cast steel prepared in Example 1 after hot-dip plating of Al-10In-5Si alloy and diffusion heat treatment; Figure 4 This is the Al element distribution diagram of the cross section of the Fe-Cr-B cast steel prepared in Example 1 after hot-dip plating of Al-10In-5Si alloy-diffusion heat treatment; Figure 5 Example 1 was prepared by using BiCl 3 Microstructure of the cross section in the corrosion area after molten salt corrosion; Figure 6 Example 1 was prepared by using BiCl 3 Cr element distribution diagram in the corrosion area of the cross section after molten salt corrosion; Figure 7 Example 1 was prepared by using BiCl 3 In element distribution diagram of the cross section in the corrosion area after molten salt corrosion; Figure 8 Example 1 was prepared by using BiCl 3 Bi element distribution diagram in the corrosion area of the cross section after molten salt corrosion; Fig. 9 Example 1 was prepared by using BiCl 3 Microstructure of the cross section in the uncorroded area after molten salt corrosion; Fig.10 Example 1 was prepared by using BiCl 3 In element distribution diagram in the uncorroded area of the cross section after molten salt corrosion; Fig.11 Example 1 was prepared by using BiCl 3 Bi element distribution diagram in the uncorroded area of the cross section after molten salt corrosion; Fig.12 This is a cross-sectional microstructure diagram of the Fe-Cr-B cast steel prepared in Example 2 after hot-dip plating with Al-10In-5Si alloy and diffusion heat treatment; Fig.13 Cr element distribution diagram of the cross section of the Fe-Cr-B cast steel prepared in Example 2 after hot-dip plating of Al-10In-5Si alloy and diffusion heat treatment; Fig.14 This is the In element distribution diagram of the cross section of the Fe-Cr-B cast steel prepared in Example 2 after hot-dip plating of Al-10In-5Si alloy and diffusion heat treatment. DETAILED DESCRIPTION
[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0022] In the following examples, Fe-Cr-B cast steel was prepared by the following method: 1. Ingredients: According to the designed alloy composition, calculate the required weight of low-carbon ferrochrome Fe-58wt.%Cr-0.06wt.%C, Fe-18 wt.%B master alloy and pig iron, with a total weight of 10kg.
[0023] 2. Melting: The raw materials weighed in step ① are loaded into a vacuum melting furnace, and after being completely melted, they are superheated to 1600° C. and kept warm for 15 minutes, and then poured into a metal mold, and after cooling, Fe-Cr-B cast steel is obtained.
[0024] The microstructure of the prepared Fe-Cr-B cast steel is mainly composed of gray-black (Cr, Fe) 2 The microstructures in the examples were photographed using a backscattered electron mode of a scanning electron microscope, and the whiter the contrast, the larger the average atomic number.
[0025] Embodiment 1: A method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution comprises the following steps: S1, hot dip aluminum: Containing borides (Cr, Fe) 2 The Fe-Cr-B cast steel of B is hot-dip plated in an aluminum alloy melt, the aluminum alloy is Al-10In-5Si alloy, the aluminum alloy melt temperature is 750°C, the hot-dip plating time is 25 minutes, and after reaching the set time, it is taken out and air-cooled to room temperature.
[0026] The meaning of Al-10In-5Si alloy is: the mass percentage of In is 10%, the mass percentage of Si is 10%, and the rest is Al.
[0027] S2. Diffusion heat treatment: The sample prepared in step S1 is placed in a muffle furnace for diffusion heat treatment, kept at 750° C. for 1 hour, and cooled to room temperature in the furnace after the set time is reached.
[0028] The sample was cut in the middle by wire cutting, and the metallographic specimen was prepared after grinding and polishing. The structure was observed by backscattered electron mode of scanning electron microscope. It was found that after hot-dip aluminum plating, the (Cr, Fe) 2 The FeAl 3The Cr-Al-B MAB phase near the outside shows a white contrast in the backscattered electron mode of the scanning electron microscope, indicating that its average atomic number becomes larger, replaced by "whitening", and whiskers can grow randomly, such as Figure 1 As shown, combined Figure 2 The Cr shown Figure 3 In, Figure 4 The Al element surface distribution is shown in Figure 1. Figure 2 The Cr shown represents the position of the Cr-Al-B MAB phase. It can be seen that the whitening of the Cr-Al-B MAB phase is caused by the In element. Combined with the characteristics of the MAB phase and In being the theoretical A-site element, it can be inferred that In partially replaces Al at the A-site of the Cr-Al-B MAB phase and forms a Cr-(Al, In)-B MAB phase solid solution, and spontaneously grows In whiskers.
[0029] S3、BiCl 3 Molten salt corrosion: The sample prepared in step S2 was immersed in a 260°C BiCl 3 Soak in the molten salt solution for 55 minutes, take it out after the set time is reached, and cool it to room temperature.
[0030] The microstructure of the polished cross section in the corrosion area is as follows Figure 5 As shown, combined Figure 6 The Cr, Figure 7 In, Figure 8 From the Bi element surface distribution shown, it can be found that the whitish part is the Cr-(Al, Bi, In)-B MAB phase solid solution, but no whiskers are grown.
[0031] The microstructure of the uncorroded area on the cross section is as follows: Fig. 9 As shown, combined Fig.10 In, Fig.11 From the Bi element surface distribution shown, it can be found that the whitish part is the Cr-(Al, In)-B MAB phase solid solution, which does not contain Bi element but spontaneously grows In whiskers.
[0032] Embodiment 2: Different from Example 1, the temperature of the aluminum alloy melt is 700°C, the hot-dip coating time is 30 minutes, and after reaching the set time, it is taken out and air-cooled to room temperature. The sample of hot-dip coated Al-10In-5Si alloy is placed in a muffle furnace for diffusion heat treatment at a temperature of 800°C for 55 minutes and then cooled with the furnace.
[0033] After diffusion heat treatment, the sample was cut in the middle by wire cutting, and the metallographic specimen was prepared after grinding and polishing. The structure was observed by backscattered electron mode of scanning electron microscope. It was found that after hot-dip aluminum plating, the (Cr, Fe) 2 The FeAl 3 The Cr-Al-B MAB phase near the outside shows a white contrast in the backscattered electron mode of the scanning electron microscope, indicating that its average atomic number becomes larger, replaced by "whitening", and whiskers can grow randomly, such as Fig.12 As shown, combined Fig.13 The Cr, Fig.14 From the surface distribution of In element shown in the figure, it can be seen that the whitening of Cr-Al-B MAB phase is caused by In element. Combined with the characteristics of MAB phase and In is the theoretical A-site element, it can be inferred that In partially replaces Al at the A-site of Cr-Al-B MAB phase and forms Cr-(Al, In)-B MAB phase solid solution, and spontaneously grows In whiskers.
[0034] After 250℃ BiCl 3 Cr-(Al, Bi, In)-B MAB phase solid solution can be generated after molten salt corrosion for 1 hour, but no whiskers grow in the Cr-(Al, Bi, In)-B MAB phase solid solution area.
[0035] The above-mentioned embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.
Claims
1. A quinary Cr-(Al, Bi, In)-B MAB phase solid solution, characterized in that: In the Cr-Al-B MAB phase, the Al atoms at the A position are partially replaced by Bi and In to form a solid solution containing Al, Bi, and In simultaneously, and the number of Bi atoms is greater than that of In.
2. The method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution according to claim 1, characterized in that: The following steps are involved: S1, hot-dip aluminum: The Fe-Cr-B cast steel containing boride (Cr, Fe)2B is hot-dipped in an aluminum alloy melt, the aluminum alloy is Al-10In-5Si alloy, the aluminum alloy melt temperature is 700-750°C, the hot-dip coating time is 25-30 minutes, and after reaching the set time, it is taken out and air-cooled to room temperature; S2. Diffusion heat treatment: The sample prepared in step S1 is placed in a muffle furnace for diffusion heat treatment, kept at 750-800°C for 55-60 minutes, and cooled to room temperature with the furnace after reaching the set time; S3, BiCl3 molten salt corrosion: The sample prepared in step S2 is immersed in a BiCl3 molten salt solution at 250°C to 260°C for 55 to 60 minutes, taken out after the set time is reached, and cooled to room temperature.
3. The method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution according to claim 2, characterized in that: In the step S1, during the hot-dip plating of Al-10In-5Si alloy, a periodic lamellar structure containing a Cr-Al-B MAB phase is first generated, and then the In atoms in the Al-10In-5Si alloy partially replace the Al atoms in the Cr-Al-B MAB phase to form a quaternary Cr-(Al, In)-B MAB phase solid solution; in the step S3, the quaternary Cr-(Al, In)-B MAB phase solid solution undergoes BiCl3 molten salt corrosion. 3+ Partially replace Al and form a quinary Cr-(Al, Bi, In)-B MAB phase solid solution.
4. The method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution according to claim 3, characterized in that: In the step S1, the Cr-(Al, In)-B MAB phase solid solution formed after hot-dip plating of the Al-10In-5Si alloy will spontaneously grow In whiskers.
5. The method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution according to claim 3, characterized in that: In the step S1, when hot-dip plating Al-10In-5Si alloy is performed, the In atoms in the aluminum alloy partially replace the Al atoms in the Cr-Al-B MAB phase and also form a nano-sized pure In phase on the grain boundary of the Cr-Al-B MAB phase.
6. The method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution according to claim 5, characterized in that: The pure In phase formed on the grain boundary during hot-dip aluminum plating is replaced by a pure Bi phase during BiCl3 molten salt corrosion.
7. The method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution according to claim 3, characterized in that: In the step S3, when BiCl3 molten salt is corroded, a five-component Cr-(Al, Bi, In)-BMAB phase solid solution is obtained by the following reaction formula: Cr-(Al, In)-B MAB phase+BiCl3→Cr-(Al, Bi, In)-B MAB phase+Bi+AlCl3↑+InCl3↑.
8. The method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution according to claim 7, characterized in that: In step S3, during BiCl3 molten salt corrosion, some Al and In atoms in the Cr-(Al, In)-B MAB phase solid solution formed during hot-dip aluminum plating in the corrosion zone will turn into gas due to the generation of corresponding volatile chlorides, so that the number of Bi atoms in the generated Cr-(Al, Bi, In)-B MAB phase solid solution is greater than that of In; after BiCl3 molten salt corrosion, the Cr-(Al, In)-B MAB phase solid solution formed during hot-dip aluminum plating in the non-corrosion zone will accelerate the growth of In whiskers.
9. The method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution according to claim 8, characterized in that: The In whiskers only grow in the Cr-(Al, In)-B MAB phase solid solution region, but not in the Cr-(Al, Bi, In)-B MAB phase solid solution region.
10. The method for preparing a quinary Cr-(Al, Bi, In)-B MAB phase solid solution according to claim 3, characterized in that: In the step S1, the generated periodic lamellar structure containing Cr-Al-B MAB phase is composed of FeAl3 and Cr-Al-B MAB phases alternately. When hot-dip Al-In-Si alloy is plated and BiCl3 molten salt is corroded, the alloy elements In and Bi have no effect on FeAl3 in the periodic lamellar structure.