Method for measuring latent heat of solidification of amorphous material and electronic device

Abstract

This invention relates to the field of amorphous material property measurement technology, specifically to a method and electronic device for determining the latent heat of solidification of amorphous materials. The method includes: measuring the DSC curve of the amorphous material under heating conditions; integrating the DSC curve to obtain the heat released during crystallization and the heat absorbed during melting; and calculating the latent heat of solidification of the amorphous material based on the heat released during crystallization and the heat absorbed during melting. This invention proposes an isenthalpic method based on the estimable latent heat of solidification during the formation of amorphous substances to determine the latent heat of solidification of amorphous materials. This method is highly efficient and provides accurate results, and can be applied to actual industrial production processes.

Description

Technical Field

[0001] This invention relates to the field of amorphous material property measurement technology, specifically to a method and electronic device for determining the latent heat of solidification of amorphous materials. Background Technology

[0002] Latent heat of solidification is the heat released when a substance changes from a liquid to a solid state. Accurate determination of this physical property parameter is of great significance; for example, a precise determination of latent heat of solidification is an important prerequisite for achieving accurate numerical simulations.

[0003] Currently, differential scanning calorimetry (DSC) is generally used to measure the latent heat of fusion of materials. However, this type of differential scanning calorimeter has a complex structure and high cost. In order to ensure measurement accuracy, only a small amount of sample can be used for measurement. The specific measurement mass is generally 1-30 milligrams, and the corresponding sample volume is basically maintained at the cubic millimeter level.

[0004] However, there are corresponding problems with directly using DSC for amorphous materials. During the gas-water atomization process, the molten metal rapidly solidifies within a millisecond timescale, forming an amorphous substance that is in a high-entropy state thermodynamically. Therefore, the latent heat of solidification in this process is much smaller than the heat released during the solidification process of normal crystalline substances. Considering that conventional temperature measurement methods cannot meet the measurement requirements in terms of time resolution, how to measure the latent heat of solidification of amorphous materials is an urgent problem to be solved. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a method and electronic device for determining the latent heat of solidification of amorphous materials. It proposes an isenthalpic method based on estimating the latent heat of solidification during the formation of amorphous substances, thereby determining the latent heat of solidification of amorphous materials. This method offers high efficiency and accurate results, and can be applied to actual industrial production processes.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a method for determining the latent heat of solidification of amorphous materials, comprising: measuring the DSC curve of the amorphous material under heating conditions; integrating the DSC curve to obtain the heat released during the crystallization process and the heat absorbed during the melting process; and calculating the latent heat of solidification of the amorphous material based on the heat released during the crystallization process and the heat absorbed during the melting process.

[0007] The formula for calculating the latent heat of solidification is:

[0008] ;

[0009] Wherein, △H s For the latent heat of solidification, ΔH cThe heat released during the crystallization process, ΔH f The heat absorbed during the melting process, f c (β) is the correction coefficient function;

[0010] ;

[0011] Where β is the heating rate during crystallization, β0 is the unit heating rate, and λ is the correction factor.

[0012] Furthermore, the heating rate during the crystallization process does not exceed 12 K / min.

[0013] Furthermore, the temperature range of the crystallization process is T. g -(80~150)K to T offset +(80~150)K, where T g T is the glass transition temperature. offset This is the crystallization termination temperature.

[0014] Furthermore, the heating rate during the melting process does not exceed 15 K / min.

[0015] Furthermore, the temperature range during the melting process is T. s -(80~150)K to T L +(80~150)K, where T s T is the solidus temperature. L This is the liquidus temperature.

[0016] Furthermore, when measuring the DSC curve, the amorphous material was taken in doses of 10-20 mg.

[0017] The present invention also provides an electronic device, including one or more processors; a memory storing one or more programs, which, when executed by the one or more processors, implement the measurement method as described above.

[0018] The beneficial effects of this invention are as follows: In the prior art, for general materials, the latent heat of solidification and the latent heat of fusion are a pair of opposite thermal processes in the phase transition of matter. They are equal in value but opposite in direction, so the detection difficulty is relatively small. However, for amorphous materials, the measurement of latent heat of solidification is extremely difficult due to rapid cooling. The solidification behavior of amorphous materials is different from that of existing materials. Specifically, during the solidification process, the initial melt forms amorphous powder through rapid cooling and releases a small amount of latent heat of solidification. The amorphous powder is then reheated to the melt. During this process, exothermic crystallization and endothermic melting occur. This invention calculates the latent heat of solidification of amorphous materials using the isenthalpic method and corrects the calculated latent heat of solidification based on the characteristics of the amorphous material itself and the heating rate. Verification shows that the calculated latent heat of solidification value is accurate and can be applied to numerical simulation processes. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the isenthalpy method provided in an embodiment of the present invention;

[0020] Figure 2 The temperature rise and fall curves provided for embodiments of the present invention;

[0021] Figure 3 The DSC curve of the amorphous powder provided in Example 1 of the present invention. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] This invention provides a method for determining the latent heat of solidification of amorphous materials, comprising: measuring the DSC curve of the amorphous material under heating conditions; integrating the DSC curve to obtain the heat released during crystallization and the heat absorbed during melting; and calculating the latent heat of solidification of the amorphous material based on the heat released during crystallization and the heat absorbed during melting.

[0025] The formula for calculating the latent heat of solidification is:

[0026] ;

[0027] Wherein, △H s Latent heat of solidification, J / g, ΔH c The heat released during the crystallization process, J / g, ΔH f The heat absorbed during the melting process, J / g, f c (β) is the correction coefficient function;

[0028] ;

[0029] Where β is the heating rate during crystallization (K / min), β0 is the unit heating rate (1 K / min), and λ is a correction factor with a value of 1 / 273. The corrected latent heat of solidification provides a more accurate result, allowing for the measurement of the latent heat of solidification in amorphous materials with an amorphous content of 90% or higher.

[0030] In existing technologies, for general materials, latent heat of solidification and latent heat of fusion are a pair of opposite thermal processes in the phase transition of matter. They are equal in value but opposite in direction, making them relatively easy to detect. However, for amorphous materials, the measurement of latent heat of solidification is extremely difficult due to rapid cooling, and the solidification behavior of amorphous materials differs from that of existing materials. This invention, without considering element loss during the heating and solidification process of the alloy, assumes that the alloy has a reversible thermodynamic path. That is, the melt can reform into amorphous powder through rapid cooling, and the amorphous powder can also reform into a crystalline melt through heating, and the initial melt and the final melt have the same enthalpy value, i.e., the isenthalpic method. A method for calculating the latent heat of solidification of amorphous materials is constructed using the isenthalpic method. Specifically, as shown... Figure 1 As shown, during solidification, the initial melt is rapidly cooled to form amorphous powder and releases a small amount of latent heat of solidification. The amorphous powder is then reheated back into the melt, resulting in exothermic crystallization and endothermic melting. Given that the initial and final melts have the same enthalpy, the total heat released during crystallization and solidification is considered equal to the heat absorbed during melting. This invention calculates the latent heat of solidification of amorphous materials using the isenthalpic method. Based on the characteristics of the amorphous material itself and the heating rate, the calculated latent heat of solidification is corrected. Verification shows that the calculated latent heat of solidification is accurate and can be applied to numerical simulations.

[0031] It should be noted that the technical solution provided by this invention can be used to measure amorphous materials with an amorphous degree of 80% or higher. The amorphous degree is calculated using Jade software: amorphous degree = amorphous peak area / (crystalline peak area + amorphous peak area).

[0032] Specifically, the heating rate during crystallization does not exceed 12 K / min. The heating rate during crystallization is crucial, significantly impacting the accuracy of latent heat calculations. Only when the heating rate is infinitely close to 0 K / min can the influence of the amorphous material itself and kinetics on the heat released during crystallization be reduced. To avoid the influence of the heating rate and the amorphous material itself on the latent heat of solidification, this application proposes a correction coefficient function to address the aforementioned issues.

[0033] Specifically, the temperature range of the crystallization process is T. g -(80~150)K to T offset +(80~150)K, where T g T is the glass transition temperature. offset T is the crystallization termination temperature. g The glass transition temperature is determined based on dynamic mechanical analysis or differential scanning calorimetry, using the temperature at which a significant shift occurs in the baseline of the heat flux curve or the first derivative curve of the heat flux during DSC testing as the starting temperature; T offset The crystallization transition termination temperature is determined based on dynamic mechanical analysis or differential scanning calorimetry, with the temperature at which the heat flow curve recovers to the baseline position after the exothermic peak of crystallization as the termination temperature of the crystallization transition.

[0034] The heating rate during the melting process does not exceed 15 K / min. The temperature range during the melting process is T. s -(80~150)K to T L +(80~150)K, where T s T is the solidus temperature. L This represents the liquidus temperature. Compared to the crystallization process, the kinetic effects of the alloy melting process are almost negligible; therefore, no correction is needed for the heat absorbed during melting. Where T... s Determined based on dynamic mechanical analysis or differential scanning calorimetry, the solidus temperature is defined as the temperature at which the melting initiation characteristic first appears on the heat flow curve (the intersection of the tangent at the point of maximum slope of the melting stage curve and the baseline); T L The liquidus temperature is determined based on dynamic mechanical analysis or differential scanning calorimetry, with the temperature at which the heat flow signal recovers to a stable baseline after the sample has completely melted being taken as the liquidus temperature.

[0035] Specifically, the experimental regime adopted in this invention is as follows: Figure 2As shown, the sample was heated rapidly (heating rate greater than 40 K / min) to a temperature point below the glass transition temperature Tg (80-150°C below Tg, maintaining a sufficient buffer temperature to prevent overheating), and held for 5-10 min to maintain temperature stability. Then, the sample was heated slowly (not exceeding 12 K / min) until fully crystallized (80-150°C above the crystallization termination temperature Toffset), and then rapidly heated again (heating rate greater than 40 K / min) to a temperature point below the solidus temperature Ts (80-150°C below Ts, maintaining a sufficient buffer temperature to prevent overheating), and held for 5-10 min to maintain temperature stability. Finally, the sample was heated slowly (less than 15 K / min) to the liquidus temperature T. L Hold the sample at one of the above temperatures (80-150℃ above Ts) for 5-10 minutes to ensure complete melting. Finally, rapidly cool the sample to room temperature (cooling rate greater than 40K / min) to end the experiment.

[0036] Since the test material in this application is an amorphous material, 10mg-20mg of the amorphous material is used when measuring the DSC curve.

[0037] This invention provides an electronic device, including: one or more processors; and a memory storing one or more programs, which, when executed by the one or more processors, implement the above-described measurement method.

[0038] The memory may include random access memory (RAM) or read-only memory (ROM). The memory can be used to store instructions, programs, code, code sets, or instruction sets. The memory may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as histogram equalization), instructions for implementing the various method embodiments described below, etc. The data storage area may also store data created during the use of the electronic device (such as image matrix data).

[0039] A processor may include one or more processing cores. The processor connects various parts of the electronic device through various interfaces and lines, and performs various functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in memory, and by calling data stored in memory. Optionally, the processor may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor may integrate one or more of a Central Processing Unit (CPU) and a modem. The CPU primarily handles the operating system and applications; the modem handles wireless communication. It is understood that the modem may also be implemented separately as a communication chip, without being integrated into the processor.

[0040] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0041] For illustrative purposes, the embodiments of the present invention use a FeSiBC alloy to measure the latent heat of solidification. Specifically, Fe... 93.1 Si 4.3 B 2.4 C 0.2 .

[0042] Example 1

[0043] Using Fe 93.1 Si 4.3 B 2.4 C 0.2 The alloy is prepared into amorphous alloy powder by gas-water atomization process, and the powder is then processed through a 300-mesh sieve to obtain powder after preliminary sieving.

[0044] 10 mg of powder was taken, and the heating rate during crystallization was 10 K / min, and the heating rate during melting was also 10 K / min. The DSC curve of the amorphous powder heated to the casting temperature under the above conditions is shown below. Figure 3 As shown, Fe 93.1 Si 4.3 B 2.4 C 0.2 The melting process of amorphous systems is complex, exhibiting four consecutive endothermic peaks in the DSC curve, corresponding to the different crystalline phases precipitated during the crystallization process. The solidus temperature T was measured. S With liquidus temperature T L Integrating the DSC curve at K values ​​of 1309.2 and 1495.9 respectively, we obtain ΔH. c With △H f The values ​​are -156.059 J / g and 186.690 J / g respectively, therefore ΔH s It is -30.631 J / g.

[0045] Example 2

[0046] Unlike Example 1, in this example, the calculation is performed using the following formula:

[0047] ;

[0048] β is taken as 10 K / min, and the calculation is obtained. It is 1.0115.

[0049] Calculate △H using the following formula. s :

[0050] ;

[0051] △H was calculated s It is -28.836 J / g.

[0052] To verify the accuracy of the calculation method provided in the embodiments of the present invention, the D50 particle size of the powder was characterized using the latent heat induction model calculated in Examples 1 and 2, respectively.

[0053] Specifically, under the conditions of 3.5 MPa atomization pressure, 3.0 mm liquid guide tube diameter and 27.5 Hz water flow frequency, the latent heat of solidification was -30.631 J / g and -28.836 J / g, respectively. The gas-water atomization process was analyzed using the turbulence-heat transfer-VOF-DPM-evaporation-solidification coupled model, and the calculated D50 values ​​were 16.84 μm and 19.80 μm, respectively.

[0054] Simultaneously, using the same process in actual industrial production, a D50 particle size of 20.7 μm was obtained.

[0055] As can be seen, the corrected relative error decreased from 18.6% to 4.3%, effectively proving the accuracy of the method.

[0056] Example 3

[0057] Using Fe 93.1 Si 4.3 B 2.4 C 0.2 The alloy is prepared into amorphous alloy powder by gas-water atomization process, and the powder is then processed through a 300-mesh sieve to obtain powder after preliminary sieving.

[0058] 20 mg of powder was used. The heating rate during crystallization was 12 K / min, and the heating rate during melting was 10 K / min. The DSC curve was measured and integrated to obtain ΔH. c With △H f The values ​​are -155.880 J / g and 186.681 J / g respectively, therefore ΔH s It is -30.801J / g.

[0059] Example 4

[0060] Unlike Example 3, in this example, the calculation is performed using the following formula:

[0061] ;

[0062] β is taken as 12K / min, and the calculation is obtained. It is 1.0126.

[0063] Calculate △H using the following formula. s :

[0064] ;

[0065] △H was calculated s It is -28.837 J / g.

[0066] Example 5

[0067] Using Fe 93.1 Si 4.3 B 2.4 C 0.2 The alloy is prepared into amorphous alloy powder by gas-water atomization process, and the powder is then processed through a 300-mesh sieve to obtain powder after preliminary sieving.

[0068] 20 mg of powder was used. The heating rate during crystallization was 1 K / min, and the heating rate during melting was 10 K / min. The DSC curve was measured and integrated to obtain ΔH. c With △H f The values ​​are -157.860 J / g and 186.691 J / g respectively, therefore ΔH s It is -28.831 J / g.

[0069] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] For those skilled in the art, various modifications and improvements can be made without departing from the concept of the present invention, and these modifications and improvements are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A method for determining the latent heat of solidification of amorphous materials, characterized in that, include: DSC curves of amorphous materials were measured under heating conditions; By integrating the DSC curve, the heat released during the crystallization process and the heat absorbed during the melting process can be obtained. The latent heat of solidification of amorphous materials is calculated based on the heat released during crystallization and the heat absorbed during melting. The formula for calculating the latent heat of solidification is: ； Wherein, △H s For the latent heat of solidification, ΔH c The heat released during the crystallization process, ΔH f The heat absorbed during the melting process, f c (β) is the correction coefficient function; ； Where β is the heating rate during crystallization, β0 is the unit heating rate, and λ is the correction factor.

2. The determination method according to claim 1, characterized in that, The heating rate during the crystallization process shall not exceed 12 K / min.

3. The determination method according to claim 1 or 2, characterized in that, The temperature range of the crystallization process is T. g -(80~150)K to T offset +(80~150)K, where T g T is the glass transition temperature. offset This is the crystallization termination temperature.

4. The determination method according to claim 3, characterized in that, The heating rate during the melting process shall not exceed 15 K / min.

5. The determination method according to claim 4, characterized in that, The temperature range during the melting process is T. s -(80~150)K to T L +(80~150)K, where T s T is the solidus temperature. L This is the liquidus temperature.

6. The determination method according to claim 1, characterized in that, When determining the DSC curve, the amorphous material should be taken at a dose of 10mg-20mg.

7. An electronic device, characterized in that, include: One or more processors; A memory having stored one or more programs that, when executed by one or more processors, implement the measurement method as described in any one of claims 1-6.

Images