A method of characterizing the relationship between nitrogen content and deformation characteristics of a ti n alloy

Abstract

The application provides a method for characterizing the relationship between the nitrogen content and deformation characteristics of TiN alloy, and relates to the technical field of titanium alloy material processing and preparation. The method establishes a relationship model between the nitrogen content and deformation characteristics of TiN alloy, obtains a functional relationship between the calculated value and the actual detected value of the yield stress of TiN alloy, predicts the yield stress value of TiN alloy within a certain deformation condition range by using the relationship model between the nitrogen content and deformation characteristics of TiN alloy, and further determines the processing window of TiN alloy. The method establishes the relationship model between the nitrogen content and deformation characteristics of TiN alloy, and accurately characterizes the high-temperature deformation characteristics of TiN alloy with different nitrogen contents. The model has the characteristics of simple calculation, accurate expression and convenient application, and solves the difficulty of low accuracy and dispersion caused by the difference of the nitrogen content in TiN alloy when the deformation characteristics of TiN alloy are described.

Description

Technical Field

[0001] This invention relates to the field of titanium alloy material processing and preparation technology, and in particular to a method for characterizing the relationship between nitrogen content and deformation characteristics of TiN alloys. Background Technology

[0002] Titanium, an important structural metal developed in the 1950s, is widely used in various fields due to its high strength and corrosion resistance. Many countries worldwide have recognized the importance of titanium alloys and have subsequently researched, developed, and applied them. Titanium alloy engine discs are defined as critical fracture components in aero engines, as their structural integrity can jeopardize the overall flight safety. Therefore, airworthiness regulations stipulate that "life-limited" components must undergo appropriate damage tolerance assessments to determine whether potential failures due to defects in materials, manufacturing, and use will occur within the approved lifespan of the part. Titanium alloy engine discs are typically manufactured through hot forming. Titanium is chemically reactive and reacts with nitrogen and other elements in the air during alloy smelting and hot forming to form TiN. During the use of titanium and titanium alloy components, TiN can become a crack initiation point, shortening the component's lifespan and causing significant harm and loss of life and property.

[0003] For TiN in titanium and titanium alloys, the nitrogen content is not a fixed value, which leads to a certain dispersion in the deformation characteristic data of TiN alloys during deformation due to different nitrogen contents. Investigating the relationship between the nitrogen content in TiN alloys and the yield stress value of the material within a certain deformation condition range has become a very urgent problem to be solved. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a method for characterizing the relationship between nitrogen content and deformation characteristics of TiN alloys, predicting the yield stress value of TiN alloys with different nitrogen contents within a certain deformation condition range, and thus characterizing the deformation characteristics of the material.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for characterizing the relationship between nitrogen content and deformation characteristics of TiN alloys, comprising:

[0006] Determine the nitrogen content in the TiN alloy;

[0007] Prepare deformed samples of TiN alloy;

[0008] The deformation characteristics of TiN alloy were determined by deformed samples of TiN alloy, and the yield stress value of TiN alloy was obtained.

[0009] A functional relationship model was established based on the nitrogen content and yield stress value of the obtained TiN alloy.

[0010] Calculate the yield stress values ​​of TiN alloy materials with different nitrogen contents, and compare these yield stress values ​​with the actual test values;

[0011] A model was established to show the relationship between nitrogen content and deformation characteristics of TiN alloy, and the functional relationship between the calculated yield stress and the actual measured value of TiN alloy was obtained.

[0012] By using a model relating nitrogen content to deformation characteristics in TiN alloys, the yield stress of TiN alloys within a certain deformation range is predicted.

[0013] Preferably, the deformation conditions of the TiN alloy include, but are not limited to, deformation temperature and strain rate.

[0014] Preferably, the nitrogen content of the TiN alloy is determined by processing the TiN alloy into a sample that meets the test standard according to the requirements of ASTM E1409-13 "Standard Test Method for Determination of Oxygen and Nitrogen in Titanium and Titanium Alloys by InertGas Fusion", and the test is conducted under conditions that meet the test environment, equipment and test personnel.

[0015] Preferably, the deformation characteristics of the TiN alloy are determined according to the requirements of HB 7571-1997 "Metallic materials - High temperature compression test method". The TiN alloy is processed into a specimen that meets the test standard, and the yield stress value of the material is measured under the test conditions, environment, equipment and test personnel.

[0016] Preferably, the relationship model between the nitrogen content and deformation characteristics of the TiN alloy is determined by the one-to-one correspondence between the nitrogen content and the yield stress of the TiN alloy, as shown in the following formula:

[0017] σ=F(N) (1)

[0018] F(N)=AN+B (2)

[0019] Where σ is the yield stress of TiN alloy under uniaxial compression, F(N) is a function of nitrogen content, A and B are fitting parameters, and N is the nitrogen content.

[0020] Preferably, the method determines fitting parameters A and B by fitting the nitrogen content and the material yield stress value in the model relating nitrogen content and deformation characteristics of TiN alloy.

[0021] Preferably, the method verifies the accuracy of the relationship model between the nitrogen content and deformation characteristics of TiN alloys by calculating the yield stress value of TiN alloys with different nitrogen contents and comparing the yield stress value with the actual test value.

[0022] Preferably, the method further determines the processing window of the TiN alloy by obtaining the yield stress value of the material within a certain deformation condition range based on the nitrogen content of the TiN alloy.

[0023] The beneficial effects of adopting the above technical solution are as follows: The method for characterizing the relationship between nitrogen content and deformation characteristics of TiN alloys provided by this invention, by determining the nitrogen content and yield stress of the TiN alloy, and establishing a relationship model using the functional relationship between nitrogen content and yield stress, can accurately predict the yield stress values ​​of TiN alloys with different nitrogen contents within a certain deformation condition range, thereby more realistically describing the characteristics of TiN alloys during the deformation process. This method solves the problem of the dispersion of deformation characteristic data of TiN alloys due to different nitrogen contents during the deformation process, thus more realistically describing the characteristics of TiN alloys during the deformation process, which is of great significance for promoting the continuous development of my country's aerospace field. Attached Figure Description

[0024] Figure 1 A flowchart illustrating a method for characterizing the relationship between nitrogen content and deformation properties of TiN alloys, provided in an embodiment of the present invention;

[0025] Figure 2 A functional relationship model diagram of nitrogen content and yield stress of TiN alloy provided in an embodiment of the present invention;

[0026] Figure 3 This is a comparison chart of the yield stress value of TiN alloy material calculated by the relational model and the actual measured yield stress value provided in the embodiments of the present invention. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0028] This embodiment takes a TiN alloy sample with different nitrogen contents as an example, and uses a model of the relationship between the nitrogen content and deformation characteristics of TiN alloy to predict the material yield stress of the TiN alloy sample with different nitrogen contents.

[0029] In this embodiment, a model characterizing the relationship between nitrogen content and deformation properties of TiN alloys is provided, such as... Figure 1 As shown, it includes the following steps:

[0030] Step 1: Determine the nitrogen content of the TiN alloy;

[0031] In this embodiment, according to the requirements of ASTM E1409-13 "Standard Test Method for Determination of Oxygen and Nitrogen in Titanium and Titanium Alloys by Inert Gas Fusion", the TiN alloy was processed into a sample that met the test standard. Under the conditions of the test environment, equipment and test personnel, the nitrogen content N in the TiN alloy was measured to be 2%, 4% and 6%.

[0032] Step 2: Prepare deformed samples of TiN alloy;

[0033] In this embodiment, the process of preparing the deformed sample of TiN alloy is as follows: First, a compression sample blank with a diameter of 9 mm and a height of 13 mm is processed by wire cutting. Then, the compression sample blank is processed into a compression sample with a diameter of 8 mm and a height of 12 mm by fine grinding. The surface roughness of the compression sample is Ra = 0.1 μm, and the parallelism of the two end faces of the sample is ±0.01 mm.

[0034] Step 3: Determine the deformation characteristics of TiN alloy through deformed samples and obtain the yield stress value of TiN alloy;

[0035] In this embodiment, the deformed TiN alloy sample was subjected to a high-temperature hot compression test on an electronic universal tensile testing machine equipped with a high-temperature heating furnace. The sample size was a cylinder with dimensions of Ф8mm × 12mm. The hot compression temperature was 950℃, the deformation amount was 60%, the heating rate during the test was 15℃ / min, and the temperature was held for 30min after reaching the set temperature to ensure uniform heating of the test sample. Each sample was tested four times. The average yield stress of the material during deformation of TiN alloy samples with different nitrogen contents of 2%, 4%, and 6% was determined to be 51MPa, 93MPa, and 147MPa, respectively.

[0036] Step 4: Determine the relationship model between nitrogen content and deformation characteristics of TiN alloy by establishing a one-to-one correspondence between nitrogen content and yield stress value of TiN alloy;

[0037] Due to the inherent properties of TiN alloys, the yield stress during deformation is affected not only by the deformation parameters but also by the nitrogen content. Therefore, under the same deformation parameters, the deformation characteristic data exhibits a certain degree of dispersion, making it impossible to accurately characterize the deformation properties of TiN alloys. According to... Figure 2The relationship between nitrogen content and yield stress values ​​in TiN alloys is shown in the model below, which establishes the relationship between nitrogen content and deformation characteristics of TiN alloys:

[0038] σ=F(N) (1)

[0039] F(N)=AN+B (2)

[0040] Where σ is the yield strength of TiN alloy under uniaxial compression, F(N) is a function of nitrogen content, A and B are fitting parameters, and N is the nitrogen content.

[0041] In this embodiment, the nitrogen content and the material yield stress value in the relationship model are fitted using Origin software, and the relationship model between the nitrogen content and deformation characteristics of TiN alloy is obtained as shown in the following formula:

[0042] σ = 23.7045N + 2.6174

[0043] Step 5: Calculate the yield stress value of TiN alloy materials with different nitrogen contents using the relationship model between nitrogen content and deformation characteristics of TiN alloy, and compare the yield stress value with the actual test value to verify the accuracy of the model;

[0044] In this embodiment, the yield stress values ​​of TiN alloys with nitrogen contents of 2%, 4%, and 6% calculated using the relationship model between nitrogen content and deformation characteristics are 50 MPa, 97 MPa, and 144 MPa, respectively. These calculated values ​​are compared with the actual measured average yield stress values ​​of 51 MPa, 93 MPa, and 147 MPa during the deformation process of TiN alloy samples with nitrogen contents of 2%, 4%, and 6%. The comparison results are as follows: Figure 3 As shown in the figure, the square dots represent the material yield stress values ​​obtained using the relational model, while the circular dots represent the yield values ​​actually measured through high-temperature compression tests. It can be seen that the theoretical yield stress results calculated by the relational model can reflect the measured values ​​well.

[0045] Step 6: Based on the verified relationship model between nitrogen content and deformation characteristics of TiN alloy, determine the material yield stress value of TiN alloy with nitrogen content between 2% and 6% during the deformation process at a deformation temperature of 950℃.

[0046] In this embodiment, the model showing the relationship between nitrogen content and yield stress of TiN alloy obtained from a compression test at a deformation temperature of 950°C is as follows: Figure 2As shown, the fitting rate is greater than 90%. In this embodiment, the nitrogen content of TiN alloy samples was 2%, 4%, and 6%, the hot compression temperature was 950℃, the heating rate during the test was 15℃ / min, and the temperature was held for 30 minutes after reaching the set point to ensure uniform heating of the test samples. The figure shows that the yield stress value of TiN alloy materials with different nitrogen contents is affected by the nitrogen content, exhibiting a certain degree of dispersion. Therefore, the method of this invention utilizes the functional relationship between nitrogen content and material yield stress value to accurately predict the material yield stress value of TiN alloy samples with different nitrogen contents within a certain deformation condition range, thus providing a more realistic, accurate, and specific characterization of the deformation process of TiN alloys.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of the present invention.

Claims

1. A method for characterizing the relationship between nitrogen content and deformation properties of TiN alloys, characterized in that: include: The nitrogen content in the TiN alloy was determined; the nitrogen content of the TiN alloy is N = 2%~6%. Prepare deformed samples of TiN alloy; The deformation characteristics of TiN alloy were determined by deformed samples of TiN alloy, and the yield stress value of TiN alloy was obtained. A functional relationship model was established based on the nitrogen content and yield stress value of the obtained TiN alloy. Calculate the yield stress values ​​of TiN alloy materials with different nitrogen contents, and compare these yield stress values ​​with the actual test values; A model was established to show the relationship between nitrogen content and deformation characteristics of TiN alloy, and the functional relationship between the calculated and actual measured values ​​of yield stress of TiN alloy was obtained. The relationship model between the nitrogen content and deformation characteristics of the TiN alloy is determined by the one-to-one correspondence between the nitrogen content and the yield stress of the TiN alloy, as shown in the following formula: （1）； （2）； in, This represents the yield stress of TiN alloy under uniaxial compression. Let N be a function of nitrogen content, where A and B are fitting parameters, and N is the nitrogen content. By using a model relating nitrogen content to deformation characteristics in TiN alloys, the yield stress of TiN alloys within a certain deformation range is predicted, thereby determining the processing window of the titanium alloy.

2. The method for characterizing the relationship between nitrogen content and deformation characteristics of TiN alloys according to claim 1, characterized in that: The deformation conditions of the TiN alloy include, but are not limited to, deformation temperature and strain rate.

3. The method for characterizing the relationship between nitrogen content and deformation characteristics of TiN alloys according to claim 1, characterized in that: The nitrogen content of the TiN alloy was determined according to the requirements of ASTM E1409-13 "Standard Test Method for Determination of Oxygen and Nitrogen in Titanium and Titanium Alloys by InertGas Fusion". The TiN alloy was processed into a sample that met the test standard and tested under the conditions of the test environment, equipment and test personnel.

4. The method for characterizing the relationship between nitrogen content and deformation characteristics of TiN alloys according to claim 1, characterized in that: The deformation characteristics of the TiN alloy are determined according to the requirements of HB 7571-1997 "Metallic materials - High temperature compression test method". The TiN alloy is processed into a specimen that meets the test standard, and the yield stress value of the material is measured under the test conditions, environment, equipment and test personnel.

5. The method for characterizing the relationship between nitrogen content and deformation characteristics of TiN alloys according to claim 4, characterized in that: The method determines the fitting parameters A and B by fitting the nitrogen content and the material yield stress value in the model relating nitrogen content and deformation characteristics of TiN alloy.

6. The method for characterizing the relationship between nitrogen content and deformation characteristics of TiN alloys according to claim 1, characterized in that: The method calculates the yield stress value of TiN alloy materials with different nitrogen contents and compares this yield stress value with the actual test value to verify the accuracy of the relationship model between the nitrogen content and deformation characteristics of TiN alloy.

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