Method for dissolving corrosion-resistant YSZ powder

Abstract

The invention relates to the technical field of chemical analysis of materials, in particular to a dissolution method of corrosion-resistant YSZ powder, and aims to solve the problems that the YSZ powder is difficult to dissolve due to a stable cubic phase structure and the existing mixed acid method has high toxicity and high risk, and the dissolution method comprises the following steps: firstly, mixing sodium peroxide and a dry YSZ sample with uniform granularity according to a mass ratio of (15-20): 1; placing in a crucible; secondly, carrying out heat preservation melting at 600-700 DEG C for 15-20 minutes, and dissolving YSZ by using sodium peroxide; and finally, transferring the melt to a beaker, boiling and washing with deionized water, and adding 20-25 mL of hydrochloric acid for acidification, so that the sample is completely dissolved. According to the method, use of highly toxic reagents such as hydrofluoric acid is avoided, operation is easy and convenient, dissolution is complete, and a reliable pretreatment scheme is provided for accurate determination of yttrium oxide and impurity elements in YSZ.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material chemical analysis, in particular to a dissolution method of corrosion-resistant YSZ powder. BACKGROUND

[0002] YSZ, yttria-stabilized zirconia, is a material that uses yttrium ions (Y 3+ ) to partially replace zirconium ions (Zr 4+ ) to form a stable cubic phase structure, thereby inhibiting high-temperature phase transition cracking. YSZ is a functional material with strong corrosion resistance, low thermal conductivity, high melting point, high hardness, and good electrical conductivity. Based on its excellent properties, YSZ can be used as a thermal barrier coating in the aerospace field to reduce the temperature of engine components and improve equipment reliability; in the biomedical field, it can be used as artificial joints, repair materials, etc.; in the energy field, it can be used as fuel cells to optimize combustion efficiency; in the electronics field, it can be used as capacitors, piezoelectric elements, and other electronic components. The variation in the content of yttria and other impurities such as silica, alumina, and iron oxide in YSZ powder can have a significant impact on the performance of YSZ. Therefore, in order to accurately determine the specific content of each component in YSZ and improve the performance stability and quality control level of YSZ derived products, a fast, reliable, and environmentally friendly sample dissolution method needs to be developed.

[0003] The existing dissolution method of YSZ powder mainly includes: a dissolution method of zirconium oxide, which adds the zirconium oxide powder into an alkaline flux, heats it to 730-750℃, and reacts for 10-15min to obtain a zirconate, the alkaline flux is sodium hydroxide or potassium hydroxide, the mass ratio of the alkaline flux to the zirconium oxide is (20-30):1; the zirconate is subjected to immersion washing treatment to obtain an immersion washing solution; aqua regia is added to the immersion washing solution to obtain a zirconium oxychloride solution. However, this scheme uses sodium hydroxide as a solvent, which cannot dissolve YSZ. A sample processing method for inductively coupled plasma spectrometric determination of electrically fused zirconia, which relates to a dissolution method of zirconia, uses a mixed acid system of perchloric acid and hydrofluoric acid for high-temperature dissolution, which has the defect of high human body hazard.

[0004] The above methods are all dissolution methods of zirconia, and do not involve YSZ, a corrosion-resistant material stabilized by yttria. In addition, no direct related patents on the dissolution method of YSZ have been found.

[0005] Therefore, it is urgent to propose a new dissolution method of YSZ powder to solve the problems of high human body hazard, long sample dissolution time, high reagent consumption, and incomplete dissolution in the prior art. SUMMARY

[0006] Therefore, the application aims to provide a method for dissolving corrosion-resistant YSZ powder, which solves the problems of great harm to human body, long sample dissolving time, high reagent consumption and incomplete dissolution in the prior art.

[0007] To solve the problems in the prior art, the application provides a method for dissolving corrosion-resistant YSZ powder.

[0008] Traditional concept considers that acid dissolution (such as HF and HClO4) or alkali fusion (such as NaOH and Na2CO3) is usually used for dissolving difficultly soluble oxides. Sodium peroxide is often regarded as an unstable and dangerous reagent due to its strong oxidizing property and violent reaction with water, and is avoided in conventional sample pretreatment to prevent safety accidents such as spattering, explosion and unnecessary oxidation side reactions. In addition, sodium peroxide at high temperature has a corrosive effect on nickel crucibles, and those skilled in the art will worry that this method will damage expensive experimental apparatus, resulting in an increase in experimental cost, which further plays a reverse teaching role.

[0009] The technical scheme of the application is implemented as follows:

[0010] The application discloses a method for dissolving corrosion-resistant YSZ powder, which comprises the following specific steps:

[0011] S1: mixing sodium peroxide with the YSZ sample to be measured and placing the mixture in a crucible, wherein the mass ratio of sodium peroxide to YSZ sample is (15-20):1;

[0012] S2: placing the nickel crucible containing the mixture into a heating device and keeping it at 600-700 DEG C for 15-20 minutes for melting;

[0013] S3: transferring the melted product to a beaker, adding deionized water for boiling washing, and then adding hydrochloric acid for acidification to completely dissolve the sample.

[0014] Further, in step S1, the YSZ sample is a dry and uniformly sized powder.

[0015] Further, in step S1, the mass ratio of sodium peroxide to YSZ sample is one of 15:1, 16:1, 17:1, 18:1, 19:1 or 20:1.

[0016] Further, in step S2, the melting temperature is 600℃, 650℃ or 700℃.

[0017] Further, in step S2, the holding time is 15 minutes, 18 minutes or 20 minutes.

[0018] Further, in step S3, the amount of hydrochloric acid used is 20-25 mL.

[0019] Further, the amount of hydrochloric acid used is 20 mL, 22 mL or 25 mL.

[0020] Further, the hydrochloric acid used is analytical pure, with a concentration of 36%-38%.

[0021] Further, the YSZ is yttria-stabilized zirconia powder.

[0022] Compared with the prior art, the method for dissolving corrosion-resistant YSZ powder has the following advantages:

[0023] 1. The method of the present application effectively overcomes the strong corrosion resistance of YSZ material due to its stable cubic phase structure by using the two-step strategy of sodium peroxide high-temperature melting combined with hydrochloric acid acidification. Compared with the traditional alkali fusion method which does not completely dissolve, the method realizes the rapid and complete dissolution of corrosion-resistant YSZ powder, solves the technical problems of high toxicity and high risk in the traditional multi-element mixed acid dissolution method and incomplete dissolution in the ordinary alkali fusion method, and provides a safe and reliable sample pretreatment basis for accurate determination of yttria and other impurity elements in YSZ.

[0024] 2. The method of the present application can completely destroy the crystal structure of YSZ by innovatively selecting sodium peroxide to melt at a suitable temperature of 600-700℃, effectively controls the corrosion degree of the nickel crucible, ensures the complete dissolution of the melting product by precise acidification of 20-25 mL of hydrochloric acid, avoids the use of highly toxic hydrofluoric acid, greatly reduces the experimental operation risk and environmental pollution, conforms to the development trend of green chemical analysis, and significantly improves the safety and environmental protection of laboratory operation.

[0025] 3. The dissolution method of the present application has a simple process and is easy to operate, only requires conventional muffle furnaces, graphite hot plates and other equipment, and has low skill requirements for the operator. The entire sample dissolution process is time-saving, consumes less reagent, and is low in cost, easy to popularize and apply in various laboratories, and has excellent practicality and repeatability. DETAILED DESCRIPTION

[0026] To make the technical means and the objectives and effects of the present invention easier to understand, the embodiments of the present invention will be described in detail below.

[0027] It should be noted that all directional and positional terms used in this invention, such as "up," "down," "left," "right," "front," "back," "vertical," "horizontal," "inner," "outer," "top," "lower," "lateral," "longitudinal," and "center," are only used to explain the relative positional relationships and connections between components in a specific state. They are merely for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0028] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0030] Analytical purity is a purity level for chemical reagents, indicating the purity grade of the reagents used in experiments. Using high-purity reagents minimizes the interference of impurities inherent in the reagent itself on the determination of target elements such as yttrium and zirconium content in YSZ powder. Using low-purity reagents may result in impurities that are detected in the final solution, leading to overestimation or errors in the analytical results. Using standardized reagents ensures comparability and repeatability of experiments conducted at different times and by different personnel, which is a fundamental requirement for scientific research and quality control.

[0031] This invention provides a method for dissolving corrosion-resistant YSZ powder. This method aims to solve the problem of the difficulty in dissolving YSZ powder due to its stable cubic phase structure, avoiding the use of highly toxic and hazardous multi-component mixed acid systems such as hydrofluoric acid or perchloric acid, while overcoming the shortcomings of common alkaline reagents such as sodium hydroxide and sodium carbonate in completely dissolving it. The method of this invention is simple to operate, safe, and environmentally friendly, achieving rapid and complete dissolution of YSZ powder. It provides a reliable sample pretreatment solution for the accurate determination of yttrium oxide (Y₂O₃) and impurity elements such as silicon, aluminum, and iron in YSZ using inductively coupled plasma atomic emission spectrometry or other analytical methods.

[0032] In this invention, the instruments used include: a nickel crucible, a polytetrafluoroethylene (PTFE) beaker, a muffle furnace with a temperature control accuracy of ±5℃, a graphite hot plate, and an analytical balance with a sensitivity of 0.1 mg. The nickel crucible effectively resists the corrosion of sodium peroxide during high-temperature melting, ensuring the integrity and lifespan of the crucible. Simultaneously, the good thermal conductivity of the nickel crucible facilitates uniform heat transfer, ensuring the uniformity of the melting reaction. The use of a PTFE beaker effectively prevents corrosion of the container and avoids the introduction of impurity ions such as iron and silicon due to container dissolution, thus ensuring the purity of the final solution and providing a reliable guarantee for subsequent high-precision elemental analysis (such as ICP-OES). Furthermore, its smooth surface makes it easy to clean, reducing sample adsorption loss. The muffle furnace has precise temperature control capabilities (temperature control accuracy ±5℃), stably maintaining the furnace temperature within the preferred range of 600–700℃, ensuring high reproducibility of experimental conditions and making the results of different batches of samples consistent and comparable, meeting the precision requirements of chemical analysis.

[0033] All reagents used were of analytical grade, specifically including: sodium peroxide (Na₂O₂), sodium carbonate (Na₂CO₃), sodium hydroxide (NaOH), and hydrochloric acid (HCl, concentration 36%–38%). In the comparative experiments, sodium carbonate (Na₂CO₃) and sodium hydroxide (NaOH) were used as references. The YSZ sample used was commercially available yttrium-stabilized zirconia powder with a yttrium oxide content of approximately 8 wt%. The sample was dried at 105°C for 2 hours before use, ensuring uniform particle size.

[0034] The method for dissolving corrosion-resistant YSZ powder includes the following specific steps:

[0035] S1: Sodium peroxide is mixed with the YSZ sample to be tested and placed in a nickel crucible, wherein the mass ratio of sodium peroxide to YSZ sample is (15~20):1;

[0036] S2: Place the nickel crucible containing the mixture into a muffle furnace and melt it at 600-700℃ for 15-20 minutes;

[0037] S3: Transfer the molten product to a polytetrafluoroethylene beaker, add deionized water to wash, and then add hydrochloric acid to acidify and completely dissolve the sample.

[0038] This method effectively overcomes the extremely strong corrosion resistance of YSZ material due to its stable cubic phase structure through a two-step treatment strategy of high-temperature melting of sodium peroxide and acidification with hydrochloric acid. Compared with the traditional alkaline fusion method, which results in incomplete dissolution, this method achieves rapid and complete dissolution of the sample, avoiding the use of highly toxic hydrofluoric acid or highly dangerous perchloric acid. The operation is safe and the process is simple, providing a reliable sample pretreatment basis for the accurate determination of yttrium oxide and impurity element content in YSZ using methods such as inductively coupled plasma optical emission spectrometry (ICP-OES).

[0039] Specifically, in step S1, the YSZ sample is a dry powder with uniform particle size.

[0040] This setup ensures good representativeness and homogeneity of the sample during weighing and mixing. A dry sample avoids the adverse effects of moisture on the high-temperature melting process, such as causing splashing or uneven localized reactions, while uniform particle size facilitates sufficient and uniform contact between the sample and sodium peroxide, thus guaranteeing the completeness and consistency of the melting reaction and improving the accuracy and reproducibility of the analytical results.

[0041] Specifically, in step S1, the mass ratio of sodium peroxide to the YSZ sample is one of 15:1, 16:1, 17:1, 18:1, 19:1 or 20:1.

[0042] This ratio range is the optimal range determined through extensive experimental verification. At this ratio, the amount of sodium peroxide is sufficient to completely destroy the crystal structure of YSZ, achieving complete dissolution of the sample; at the same time, it avoids the excessive use of sodium peroxide, thereby reducing corrosion of the nickel crucible and the potential impact of excessive alkaline substances on subsequent acidification steps and analytical instruments, thus balancing dissolution efficiency and operational economy.

[0043] Specifically, in step S2, the melting temperature is 600°C, 650°C, or 700°C.

[0044] This temperature range is crucial for the effective decomposition of YSZ. If the temperature is too low, such as below 600℃, the reaction rate is slow, potentially leading to incomplete melting; if the temperature is too high, such as above 700℃, it will significantly accelerate the corrosion of the nickel crucible, causing a large amount of nickel ions to dissolve, contaminating the sample solution and interfering with subsequent elemental analysis. A temperature of 600–700℃ ensures the reaction proceeds fully while effectively controlling crucible wear, representing the optimal condition for balancing dissolution efficiency and sample purity.

[0045] Specifically, in step S2, the heat preservation time is 15 minutes, 18 minutes, or 20 minutes.

[0046] This time range ensures sufficient time for the melting reaction to complete. Experiments show that a holding time of less than 15 minutes may result in incomplete reaction and incomplete dissolution; while a holding time exceeding 20 minutes offers limited improvement in dissolution and instead increases energy consumption and crucible erosion time at high temperatures. Therefore, a holding time of 15–20 minutes achieves high operational efficiency while ensuring complete dissolution.

[0047] Specifically, in step S3, the amount of hydrochloric acid used is 20-25 mL.

[0048] This dosage represents the optimized acidification conditions. Insufficient hydrochloric acid (less than 20 mL) will fail to neutralize the alkaline substances in the molten product and completely dissolve the generated salts, potentially leading to turbidity or precipitation. Excessive hydrochloric acid (more than 25 mL) will unnecessarily dilute the sample, increasing the difficulty of subsequent analysis or requiring a larger final volume. A dosage of 20–25 mL of hydrochloric acid ensures complete acidification and dissolution of the molten material while maintaining an appropriate solution concentration, which is beneficial for accurate subsequent determinations.

[0049] Preferably, the amount of hydrochloric acid used is 20 mL, 22 mL, or 25 mL.

[0050] The specific values ​​set are the optimal solution determined based on the convenience of actual operation, such as the commonly used scale of pipettes and the principle of reagent conservation, while ensuring complete dissolution. The operation is simple and easy to standardize in the laboratory.

[0051] Specifically, the hydrochloric acid used was of analytical grade and had a concentration of 36%–38%.

[0052] Using analytical grade hydrochloric acid minimizes impurities in the reagent itself, such as Fe. 3+ Al 3+ To minimize interference from metal ions in the determination of target elements in YSZ, the accuracy of analytical results is ensured. A hydrochloric acid concentration of 36%–38% is a common concentration of commercially available concentrated hydrochloric acid, readily available, and possesses sufficient acidity to complete the acidification process, making it a frequently used choice in industrial and laboratory settings.

[0053] Specifically, YSZ is yttrium oxide stabilized zirconium oxide powder.

[0054] This characteristic clarifies the specific materials to which this method is applicable. Yttrium-stabilized zirconium oxide (YSZ), typically referring to ZrO2 with a Y2O3 content of 3–8 mol%, is the most commonly used YSZ type in fields such as thermal barrier coatings and solid oxide fuel cells, exhibiting extremely high chemical stability and corrosion resistance. The method of this invention is specifically designed to address the poor solubility of such materials, solving key technical challenges in their compositional analysis, and possesses clear application focus and practicality.

[0055] Example 1: The effect of the type of alkaline reagent on the solubility

[0056] To investigate the effect of different alkaline reagents on the dissolution of YSZ powder, this example uses sodium peroxide, sodium carbonate, and sodium hydroxide for comparative experiments. The specific procedures are as follows: 0.1 g of dry YSZ sample was accurately weighed and mixed thoroughly with 2.0 g of sodium peroxide, sodium carbonate, or sodium hydroxide in a nickel crucible. The nickel crucible was placed in a muffle furnace and melted at 700°C for 20 minutes. After melting, the crucible was removed and cooled. The molten material was then transferred to a polytetrafluoroethylene beaker, 30 mL of deionized water was added, and the mixture was boiled on a graphite hot plate for 5 minutes to completely remove the molten material from the crucible. Subsequently, 30 mL of hydrochloric acid was added, and the mixture was stirred until the sample was completely dissolved.

[0057] Table 1. Effect of alkaline reagent type on the dissolution effect of YSZ powder

[0058]

[0059] The experimental results are shown in Table 1. When sodium peroxide was used as the melting agent, the sample dissolved completely, resulting in a clear and transparent solution. However, when sodium carbonate or sodium hydroxide was used as the melting agent, insoluble matter was present in the solution. This indicates that sodium peroxide can effectively disrupt the stable structure of YSZ and is the key reagent for achieving its complete dissolution.

[0060] Example 2: Effect of sodium peroxide dosage on dissolution effect

[0061] After determining sodium peroxide as the optimal flux, this example further investigates the effect of its dosage on the dissolution effect. With a fixed sample weight of 0.1 g, a melting temperature of 700 °C, a melting time of 20 minutes, and a hydrochloric acid dosage of 30 mL, the dissolution effect was investigated when sodium peroxide dosages were 1.0 g, 1.5 g, 1.8 g, and 2.0 g.

[0062] Table 2. Effect of alkaline reagent dosage on the dissolution effect of YSZ powder

[0063]

[0064] The experimental results are shown in Table 2. When the amount of sodium peroxide was 1.0 g, i.e., the mass ratio to YSZ was 10:1, insoluble matter was present in the solution. When the amount of sodium peroxide was increased to 1.5 g, 1.8 g, or 2.0 g, i.e., the mass ratio was 15:1, 18:1, or 20:1, the sample could be completely dissolved. Therefore, to ensure complete dissolution while considering the amount of reagent used, the preferred mass ratio of sodium peroxide to YSZ sample is 15:1 to 20:1.

[0065] Example 3: Effect of melting temperature on dissolution effect

[0066] This embodiment investigates the effect of melting temperature on the dissolution of YSZ powder. A fixed YSZ sample weight of 0.1 g, sodium peroxide dosage of 1.5 g, melting time of 20 minutes, and hydrochloric acid dosage of 30 mL were used. Melting experiments were conducted at 500℃, 600℃, 700℃, and 800℃.

[0067] Table 3. Effect of melting temperature on the dissolution effect of YSZ powder

[0068]

[0069] The experimental results are shown in Table 3. The samples dissolved completely within a temperature range of 500℃ to 800℃. However, with increasing temperature, the corrosion of the nickel crucible significantly intensified, leading to a decrease in the concentration of nickel ions (Ni) in the final solution. 2+ The significantly increased content of [agent name] may interfere with subsequent elemental analysis. Furthermore, excessively high temperatures also increase energy consumption. Considering dissolution efficiency, reagent contamination, and energy consumption, the preferred melting temperature range is 600℃ to 700℃.

[0070] Example 4: Effect of melting time on dissolution effect

[0071] This example investigates the effect of melting time on the dissolution effect. A fixed YSZ sample weight of 0.1 g, sodium peroxide dosage of 1.5 g, melting temperature of 600 °C, and hydrochloric acid dosage of 30 mL were used. Melting was carried out at this temperature for 10 min, 15 min, 20 min, and 30 min, respectively.

[0072] Table 4. Effect of melting time on the dissolution effect of YSZ powder

[0073] The experimental results are shown in Table 4. Insoluble matter still existed in the solution 10 minutes after melting. The samples completely dissolved when the melting time was extended to 15, 20, or 30 minutes. To ensure complete reaction of the samples and reduce prolonged high-temperature corrosion of the nickel crucible, a melting time of 15 to 20 minutes is preferred.

[0074] Example 5: Effect of hydrochloric acid dosage on dissolution effect

[0075] This embodiment investigates the effect of hydrochloric acid dosage on the final dissolution effect. The YSZ sample weight was fixed at 0.1 g, the sodium peroxide dosage at 1.5 g, the melting temperature at 600 °C, and the melting time at 20 min. After melting and water leaching, 10 mL, 15 mL, 20 mL, 25 mL, and 30 mL of hydrochloric acid were added for acidification, respectively.

[0076] Table 5. Effect of hydrochloric acid dosage on the dissolution effect of YSZ powder

[0077]

[0078] The experimental results are shown in Table 5. When the amount of hydrochloric acid used was 10 mL and 15 mL, the solution was suspended and turbid, indicating that the amount of acid was insufficient and all salts were not completely dissolved. When the amount of hydrochloric acid used reached 20 mL, 25 mL, or 30 mL, the solution was clear and transparent, and the sample was completely dissolved. To save reagents while ensuring complete dissolution, the preferred amount of hydrochloric acid used is 20 mL to 25 mL.

[0079] Example 6: Comprehensive Verification of the Method of the Invention

[0080] Take 0.1g of YSZ sample and dissolve it according to the preferred method of this invention: mix the sample with 1.8g of sodium peroxide in a nickel crucible and melt it in a muffle furnace at 650℃ for 18 minutes. After cooling, transfer the melt to a polytetrafluoroethylene beaker, add an appropriate amount of deionized water to wash it, then add 22mL of hydrochloric acid for acidification and stir until completely dissolved. The resulting solution is clear and transparent, without any residue. After diluting and making up to volume, the yttrium content is determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Six parallel determinations were performed, and the relative standard deviation (RSD) of the results was less than 1.5%, indicating that the dissolution effect of the method of this invention is stable and uniform, and can meet the requirements of high-precision chemical analysis.

[0081] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for dissolving corrosion-resistant YSZ powder, characterized in that, The specific steps include the following: S1: Sodium peroxide is mixed with the YSZ sample to be tested and placed in a crucible, wherein the mass ratio of sodium peroxide to YSZ sample is (15~20):1; S2: Place the crucible containing the mixture into the heating device and keep it at 600-700℃ for 15-20 minutes to melt it; S3: Transfer the molten product to a beaker, add deionized water to wash, and then add hydrochloric acid to acidify it so that the sample is completely dissolved.

2. The method for dissolving corrosion-resistant YSZ powder according to claim 1, characterized in that, In step S1, the YSZ sample is a dry powder with uniform particle size.

3. The method for dissolving corrosion-resistant YSZ powder according to claim 2, characterized in that, In step S1, the mass ratio of sodium peroxide to the YSZ sample is one of 15:1, 16:1, 17:1, 18:1, 19:1 or 20:

1.

4. The method for dissolving corrosion-resistant YSZ powder according to claim 1, characterized in that, In step S2, the melting temperature is 600°C, 650°C, or 700°C.

5. The method for dissolving corrosion-resistant YSZ powder according to claim 1, characterized in that, In step S2, the heat preservation time is 15 minutes, 18 minutes, or 20 minutes.

6. The method for dissolving corrosion-resistant YSZ powder according to claim 1, characterized in that, In step S3, the amount of hydrochloric acid used is 20-25 mL.

7. The method for dissolving corrosion-resistant YSZ powder according to claim 6, characterized in that, The amount of hydrochloric acid used is 20 mL, 22 mL, or 25 mL.

8. The method for dissolving corrosion-resistant YSZ powder according to claim 6, characterized in that, The hydrochloric acid used was of analytical grade and had a concentration of 36%–38%.

9. The method for dissolving corrosion-resistant YSZ powder according to claim 1, characterized in that, YSZ is yttrium oxide stabilized zirconium oxide powder.

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