A powder metallurgy part hot deformation detection system and method

Abstract

The present invention discloses a hot deformation detection system and method for powder metallurgy parts, which relates to the technical field of hot deformation detection, and includes: filling an inert gas into the detection chamber, debugging the resistance furnace, calibrating the temperature control system, clamping the powder metallurgy part specimen in the detection chamber, monitoring the internal and surface temperatures of the powder metallurgy part, adjusting the heating rate, cooling after heating; measuring the coordinates of the characteristic points on three arcs centered on the standard axis point on the upper and lower cross-sections of the powder metallurgy part, calculating the measured axis point coordinates of the upper and lower ends of the powder metallurgy part, calculating the axis point offset distance of the powder metallurgy part, calculating the axis offset angle, calculating the axis offset index; obtaining the height difference between the characteristic points and the standard plane, calculating the flatness coefficient of the powder metallurgy part, calculating the expansion and contraction coefficient of the powder metallurgy part, calculating the surface deformation index of the powder metallurgy part; obtaining the axis offset index and the surface deformation index of the powder metallurgy part, and calculating the hot deformation index of the powder metallurgy part.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal deformation detection, and specifically to a thermal deformation detection system and method for powder metallurgy parts. Background Technique

[0002] With the development of powder metallurgy technology, due to its advantages such as high material utilization rate and easy to form complex structures, it has been widely used in the fields of automobile manufacturing, aviation, etc. However, traditional thermal deformation detection of powder metallurgy parts often relies on contact measurement, with a high risk of loss of the measuring piece and easy interference with the state of the measured piece. Therefore, how to accurately detect the thermal deformation of powder metallurgy parts has become the key to improving product quality and process.

[0003] In the Chinese invention application with the application publication number CN119188417A, a method for detecting the thermal deformation of the A-axis of a five-axis machine tool based on a trigger probe is disclosed, including measuring the coordinates of each measurement reference point at each measurement position when the machine tool is powered on, and calculating the initial center coordinates of the standard ball at each measurement position when powered on; entering the rotation axis cycle stage, measuring the coordinates of each measurement reference point at each measurement position, calculating the center coordinates of the standard ball at each measurement position in the cycle stage, and calculating the thermal deformation value of the A-axis, and determining whether the cooling condition is reached. If so, enter the cooling stage, otherwise execute the rotation axis cycle stage; enter the cooling stage, measure the coordinates of each measurement reference point at each measurement position, calculate the center coordinates of the standard ball at each measurement position, and calculate the thermal deformation value of the A-axis, and determine whether the interruption measurement condition is reached. If so, obtain the detection result of the thermal deformation value of the A-axis, improving the detection accuracy and achieving a comprehensive detection of the thermal deformation of the A-axis of the five-axis machine tool.

[0004] In the above invention application, by measuring the coordinates of each measurement reference point, measuring the coordinates of each measurement reference point at each measurement position, calculating the center coordinates of the standard ball at each measurement position, and calculating the thermal deformation value of the A-axis, it is determined whether to enter the cooling stage or interrupt the test, but it is unable to effectively evaluate the surface deformation of the measuring piece, and only calculates and evaluates the axial center offset of the measuring piece, and cannot effectively and comprehensively reflect the thermal deformation of the measuring piece.

[0005] Therefore, the present invention provides a thermal deformation detection system and method for powder metallurgy parts. Summary of the Invention

[0006] (I) Technical Problems to be Solved

[0007] Aiming at the deficiencies of the prior art, the present invention provides a thermal deformation detection system and method for powder metallurgy parts. By precisely controlling the heating of the powder metallurgy parts to ensure that they are not affected by improper heating, analyzing the surface deformation of the powder metallurgy parts and calculating the axial center point offset distance of the powder metallurgy parts and calculating the axial center offset angle , calculate the axis offset index , analyze the axis offset and calculate the flatness coefficient of the powder metallurgy part , calculate the expansion and contraction coefficient of the powder metallurgy part , calculate the surface deformation index of the powder metallurgy part , finally calculate the thermal deformation index of the powder metallurgy part Comprehensively evaluate the thermal deformation of the powder metallurgy part, thus solving the problems described in the background technology.

[0008] (II) Technical solution

[0009] To achieve the above objectives, the present invention is realized through the following technical solutions: A method for detecting the thermal deformation of a powder metallurgy part, including the following steps:

[0010] Fill the detection chamber with inert gas, debug the resistance furnace, calibrate the temperature control system so that the temperature error remains within 5°C, clamp the powder metallurgy part specimen in the detection chamber, use a thermocouple and an infrared thermometer to monitor the internal and surface temperatures of the powder metallurgy part, adjust the heating rate so that the temperature difference is less than 30°C, and cool it after heating;

[0011] Use a laser scanner to measure the coordinates of the feature points on three arcs centered on the standard axis point on the upper and lower cross-sections of the powder metallurgy part , , , , , , calculate the measured axis point coordinates of the upper and lower ends of the powder metallurgy part , , calculate the axis point offset distance of the powder metallurgy part , measure the distance between the upper and lower cross-sections , calculate the axis offset angle , calculate the axis offset index ;

[0012] Use a laser scanner to scan the feature points on the same horizontal plane of the powder metallurgy part before heating, and obtain the height difference between the feature points and the standard plane , calculate the flatness coefficient of the powder metallurgy part , measure the perimeter of the upper cross-section of the powder metallurgy part and the area , calculate the expansion and contraction coefficient of the powder metallurgy part , calculate the surface deformation index of the powder metallurgy part ;

[0013] Obtain the axis offset index and the surface deformation index , calculate the thermal deformation index of the powder metallurgy part 。

[0014] Furthermore, inert gas is filled into the detection chamber, and the resistance furnace is debugged according to the material selection of the powder metallurgy part Ar 、 or in a vacuum environment to calibrate the temperature control system so that the temperature error is kept within 5°C, ensuring the accuracy of temperature control.

[0015] Furthermore, a laser scanner is used to measure the coordinates of the feature points on three arcs centered on the standard axis point on the upper and lower cross-sections of the powder metallurgy part , , , , , ,and calculate the measured axis point coordinates of the upper and lower ends of the powder metallurgy part , :

[0016] ;

[0017] ;

[0018] ;

[0019] wherein, represents the number of each powder metallurgy part, = 1, 2, …, m, m is a positive integer, the standard axis point coordinates are (0, 0), , , , represents the coordinates in the upper cross-section of the powder metallurgy part, , , , represents the coordinates in the lower cross-section of the powder metallurgy part.

[0020] Furthermore, obtain the measured axis point coordinates of the upper and lower ends of the powder metallurgy part , ,and calculate the axis point offset distance of the powder metallurgy part :

[0021] ; The calculation formula of the axis point offset distance is as above.

[0022] Furthermore, use a laser scanner to measure the lateral distance between the measured axis points at the upper and lower ends of the powder metallurgy part ,measure the distance between the upper and lower cross-sections ,and calculate the axis offset angle : ; The axis offset angle has the above calculation formula.

[0023] Further, obtain the axis point offset distance and the axis offset angle of the powder metallurgy part, and calculate the axis offset index :

[0024] ; When the axis offset index ≥ 1, it indicates that the powder metallurgy part has an axis offset problem;

[0025] Among them, represents the maximum allowable axis offset distance for processing the powder metallurgy part, represents the maximum allowable axis offset angle for processing the powder metallurgy part.

[0026] Further, use a laser scanner to scan the feature points on the same horizontal plane of the powder metallurgy part before heating, and obtain the height difference between the feature points and the standard plane, and calculate the flatness coefficient of the powder metallurgy part:

[0027] ; Among them, j represents the number of each feature point, j = 1, 2,..., n, n is a positive integer, represents the average value of the height differences between all feature points and the standard plane.

[0028] Further, measure the perimeter and area of the upper cross-section of the powder metallurgy part, and calculate the expansion and contraction coefficient of the powder metallurgy part:

[0029] ; Among them, represents the standard value of the perimeter of the powder metallurgy part, represents the standard value of the area of the powder metallurgy part.

[0030] Further, obtain the flatness coefficient and the expansion and contraction coefficient of the powder metallurgy part, and calculate the surface deformation index of the powder metallurgy part:

[0031] ; When the surface deformation index + , it indicates that the surface of the powder metallurgy part is significantly deformed.

[0032] Among them, represents the mean value of the surface deformation indices of all powder metallurgy component specimens before heating in the same batch , represents the standard deviation of the surface deformation indices of all powder metallurgy component specimens before heating in the same batch .

[0033] Furthermore, obtain the axial center offset index and the surface deformation index of the powder metallurgy component, and calculate the thermal deformation index of the powder metallurgy component: ; when the thermal deformation index ≥1, it indicates that the thermal deformation of the powder metallurgy component is relatively serious.

[0034] A thermal deformation detection system for powder metallurgy components, comprising:

[0035] A metallurgy component heating module, including a heating control unit and a temperature uniformity control unit, for accurately controlling the temperature during the heating process of the powder metallurgy component, and avoiding affecting the thermal deformation detection result due to uneven temperature distribution of the powder metallurgy component;

[0036] An axial center offset evaluation module, including an offset distance evaluation unit, an offset angle evaluation unit and an offset comprehensive evaluation unit, for analyzing the axial center point position and axial center angle of the powder metallurgy component to obtain the axial center point offset distance , the axial center offset angle and the axial center offset index ;

[0037] A surface deformation evaluation module, including a flatness evaluation unit, a swelling and shrinking degree evaluation unit and a surface deformation evaluation unit, for analyzing the surface flatness, perimeter and area of the powder metallurgy component to obtain the flatness coefficient , the swelling and shrinking coefficient and the surface deformation index of the powder metallurgy component;

[0038] A thermal deformation evaluation module, including a thermal deformation evaluation unit, for comprehensively analyzing the axial center offset index and the surface deformation index of the powder metallurgy component to obtain the thermal deformation index .

[0039] (III) Beneficial effects

[0040] The present invention provides a thermal deformation detection system and method for powder metallurgy components, having the following beneficial effects:

[0041] By filling the detection chamber with inert gas, debugging the resistance furnace, and calibrating the temperature control system to keep the temperature error within 5°C, clamping the powder metallurgy part specimen in the detection chamber, using a thermocouple and an infrared thermometer to monitor the internal and surface temperatures of the powder metallurgy part, adjusting the heating rate to make the temperature difference less than 30°C, and cooling after heating, it is possible to ensure precise control of the temperature during the heating process of the powder metallurgy part and avoid affecting the thermal deformation detection results due to uneven temperature distribution of the powder metallurgy part.

[0042] By using a laser scanner to measure the coordinates of the feature points on three arcs centered on the standard axis point on the upper and lower cross-sections of the powder metallurgy part , , , , , , calculating the measured axis point coordinates of the upper and lower ends of the powder metallurgy part , , calculating the axis point offset distance of the powder metallurgy part , measuring the distance between the upper and lower cross-sections , calculating the axis offset angle , calculating the axis offset index , it is possible to effectively judge the axis offset situation of the powder metallurgy part after thermal deformation and avoid the unqualified final product caused by the axis offset of the powder metallurgy part.

[0043] 3. By using a laser scanner to scan the feature points on the same horizontal plane of the powder metallurgy part before heating, obtaining the height difference between the feature points and the standard plane , calculating the flatness coefficient of the powder metallurgy part , measuring the perimeter of the upper cross-section of the powder metallurgy part and area , calculating the expansion and contraction coefficient of the powder metallurgy part , calculating the surface deformation index of the powder metallurgy part , it is possible to comprehensively detect and evaluate the surface flatness, perimeter, and area of the powder metallurgy part, which helps to understand the deformation situation on the surface of the powder metallurgy part.

[0044] 4. By obtaining the axis offset index and surface deformation index of the powder metallurgy part, calculating the thermal deformation index of the powder metallurgy part, it is possible to comprehensively evaluate the thermal deformation situation of the powder metallurgy part from two aspects of axis offset and surface deformation, which helps to more comprehensively judge the thermal deformation situation of the powder metallurgy part. Description of the Drawings

[0045] Figure 1Schematic flow chart of a method for detecting thermal deformation of a powder metallurgy part according to the present invention;

[0046] Figure 2 Schematic structural diagram of a system for detecting thermal deformation of a powder metallurgy part according to the present invention. Specific embodiments

[0047] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0048] Please refer to Figure 1 , the present invention provides a method for detecting thermal deformation of a powder metallurgy part, including the following steps:

[0049] Step 1: Fill the detection cavity with inert gas, debug the resistance furnace, calibrate the temperature control system to keep the temperature error within 5°C, clamp the powder metallurgy part sample in the detection cavity, use a thermocouple and an infrared thermometer to monitor the internal and surface temperatures of the powder metallurgy part, adjust the heating rate to make the temperature difference less than 30°C, and perform cooling after heating.

[0050] Step 101: Fill the detection cavity with inert gas, select Ar , or a vacuum environment to debug the resistance furnace, calibrate the temperature control system to keep the temperature error within 5°C, and ensure the accuracy of temperature control.

[0051] Step 102: Clamp the powder metallurgy part sample in the detection cavity, use a thermocouple and an infrared thermometer to monitor the internal and surface temperatures of the powder metallurgy part, adjust the heating rate to make the temperature difference less than 30°C, avoid inaccurate thermal deformation detection caused by local overheating, and perform cooling after heating.

[0052] During use, combine the contents of steps 101 to 102:

[0053] By filling the detection cavity with inert gas, debugging the resistance furnace, calibrating the temperature control system to keep the temperature error within 5°C, clamping the powder metallurgy part sample in the detection cavity, using a thermocouple and an infrared thermometer to monitor the internal and surface temperatures of the powder metallurgy part, adjusting the heating rate to make the temperature difference less than 30°C, and performing cooling after heating, it is possible to ensure accurate temperature control during the heating process of the powder metallurgy part and avoid affecting the thermal deformation detection result due to uneven temperature distribution of the powder metallurgy part.

[0054] Step 2: Use a laser scanner to measure the coordinates of the feature points on three arcs centered on the standard axis point on the upper and lower cross-sections of the powder metallurgy part , , , , , , calculate the coordinate of the measurement center point at the upper and lower ends of the powder metallurgy part , , calculate the offset distance of the center point of the powder metallurgy part , measure the distance between the upper and lower cross-sections , calculate the center offset angle , calculate the center offset index .

[0055] Step 201: Use a laser scanner to measure the coordinates of the feature points on three arcs centered at the standard center point on the upper and lower cross-sections of the powder metallurgy part , , , , , , calculate the coordinate of the measurement center point at the upper and lower ends of the powder metallurgy part , :[[]]

[0056] ;

[0057] ;

[0058] ; where represents the number of each powder metallurgy part, = 1, 2,..., m, m is a positive integer, the standard center point coordinate is (0,0), , , , represents the coordinate in the upper cross-section of the powder metallurgy part, , , , represents the coordinate in the lower cross-section of the powder metallurgy part.

[0059] Step 202: Obtain the coordinate of the measurement center point at the upper and lower ends of the powder metallurgy part , , calculate the offset distance of the center point of the powder metallurgy part :[[]]

[0060]

[0061] Step 203: Use a laser scanner to measure the lateral distance between the measurement center points at the upper and lower ends of the powder metallurgy part , measure the distance between the upper and lower cross-sections , calculate the axis offset angle :

[0062]

[0063] Step 204: Obtain the axis point offset distance of the powder metallurgy part and the axis offset angle , calculate the axis offset index :

[0064] ; When the axis offset index ≥1, it indicates that the powder metallurgy part has an axis offset problem.

[0065] Among them, represents the maximum allowable axis offset distance for processing the powder metallurgy part, represents the maximum allowable axis offset angle for processing the powder metallurgy part.

[0066] When in use, combine the content in Steps 201 to 204:

[0067] By using a laser scanner to measure the coordinates of the feature points on three arcs centered on the standard axis point on the upper and lower cross-sections of the powder metallurgy part , , , , , , calculate the measured axis point coordinates of the upper and lower ends of the powder metallurgy part , , calculate the axis point offset distance of the powder metallurgy part , measure the distance between the upper and lower cross-sections , calculate the axis offset angle , calculate the axis offset index , it can effectively judge the axis offset situation of the powder metallurgy part after thermal deformation, and avoid the unqualified final product caused by the axis offset of the powder metallurgy part.

[0068] Step 3: Use a laser scanner to scan the feature points on the same horizontal plane of the powder metallurgy part before heating, and obtain the height difference between the feature points and the standard plane , calculate the flatness coefficient of the powder metallurgy part , measure the perimeter and area of the upper cross-section of the powder metallurgy part, calculate the expansion and contraction coefficient of the powder metallurgy part, calculate the surface deformation index .

[0069] Step 301: Use a laser scanner to scan the feature points on the same horizontal plane of the powder metallurgy part before heating, obtain the height difference between the feature points and the standard plane, and calculate the flatness coefficient of the powder metallurgy part. : :

[0070]

[0071] Wherein, j represents the number of each feature point, j = 1, 2, …, n, n is a positive integer, represents the mean value of the height differences between all feature points and the standard plane .

[0072] Step 302: Measure the perimeter and area of the upper cross-section of the powder metallurgy part, and calculate the expansion and contraction coefficient of the powder metallurgy part :

[0073]

[0074] Wherein, represents the standard value of the perimeter of the powder metallurgy part, represents the standard value of the area of the powder metallurgy part.

[0075] Step 303: Obtain the flatness coefficient and the expansion and contraction coefficient of the powder metallurgy part, and calculate the surface deformation index of the powder metallurgy part :

[0076]

[0077] When the surface deformation index + , it indicates that the surface deformation of the powder metallurgy part is obvious.

[0078] Wherein, represents the mean value of the surface deformation indices of all powder metallurgy part specimens in the same batch before heating , represents the standard deviation of the surface deformation indices of all powder metallurgy part specimens in the same batch before heating .

[0079] When in use, combine the content in Steps 301 to 303:

[0080] By using a laser scanner to scan the feature points on the same horizontal plane of the powder metallurgy part before heating, obtain the height difference between the feature points and the standard plane , and calculate the flatness coefficient of the powder metallurgy part , measure the perimeter and area of the upper cross-section of the powder metallurgy part, calculate the expansion and contraction coefficient of the powder metallurgy part, calculate the surface deformation index of the powder metallurgy part,

[0081] Step 4. Obtain the axial center offset index and surface deformation index of the powder metallurgy part, and calculate the thermal deformation index

[0082] Step 401. Obtain the axial center offset index and surface deformation index of the powder metallurgy part, and calculate the thermal deformation index

[0083] ; when the thermal deformation index ≥1, it indicates that the thermal deformation of the powder metallurgy part is relatively serious.

[0084] During use, combine the content in Step 401:

[0085] By obtaining the axial center offset index and surface deformation index of the powder metallurgy part, calculate the thermal deformation index

[0086] Please refer to Figure 2 , the present invention provides a thermal deformation detection system for powder metallurgy parts, including:

[0087] A metallurgy part heating module, including a heating control unit and a temperature uniformity control unit, which is used to accurately control the temperature during the heating process of the powder metallurgy part to avoid affecting the thermal deformation detection result due to uneven temperature distribution of the powder metallurgy part;

[0088] An axial center offset evaluation module, including an offset distance evaluation unit, an offset angle evaluation unit and an offset comprehensive evaluation unit, which is used to analyze the axial center point position and axial center angle of the powder metallurgy part to obtain the axial center point offset distance , axial center offset angle and axial center offset index ;

[0089] The surface deformation evaluation module, including a flatness evaluation unit, a swelling and shrinkage degree evaluation unit, and a surface deformation evaluation unit, is used to analyze the surface flatness, perimeter, and area of the powder metallurgy part to obtain the flatness coefficient and the swelling and shrinkage coefficient and the surface deformation index of the powder metallurgy part ;

[0090] The thermal deformation evaluation module, including a thermal deformation evaluation unit, is used to comprehensively analyze the axial center offset index and the surface deformation index of the powder metallurgy part to obtain the thermal deformation index .

[0091] The above embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution.

[0092] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0093] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered within the protection scope of this application.

Claims

1. A method for detecting thermal deformation of powder metallurgy parts, characterized in that: The following steps are involved: Fill the test cavity with inert gas, debug the resistance furnace, calibrate the temperature control system to keep the temperature error within 5°C, clamp the powder metallurgy sample in the test cavity, use thermocouples and infrared thermometers to monitor the internal and surface temperatures of the powder metallurgy parts, adjust the heating rate to make the temperature difference less than 30°C, and cool after heating; Use a laser scanner to measure the coordinates of the characteristic points on three arcs with the standard axis point as the center on the upper and lower cross sections of the powder metallurgy parts , , , , , , calculate the coordinates of the measuring axis points of the upper and lower ends of the powder metallurgy parts , , calculate the axis point offset distance of the powder metallurgy part , measure the distance between the upper and lower sections , calculate the axis offset angle , calculate the axis deviation index ; Use a laser scanner to scan the characteristic points on the same horizontal plane of the powder metallurgy part before heating to obtain the height difference between the characteristic points and the standard plane , calculate the flatness coefficient of powder metallurgy parts , measure the circumference of the upper section of the powder metallurgy part and area , calculate the expansion and contraction coefficient of powder metallurgy parts , calculate the surface deformation index of powder metallurgy parts ; Obtaining the axis deviation index of powder metallurgy parts and surface deformation index , calculate the thermal deformation index of powder metallurgy parts .

2. A method for detecting thermal deformation of powder metallurgy parts according to claim 1, characterized in that: Use a laser scanner to measure the coordinates of the characteristic points on three arcs with the standard axis point as the center on the upper and lower cross sections of the powder metallurgy parts , , , , , , calculate the coordinates of the measuring axis points of the upper and lower ends of the powder metallurgy parts , : ； ； ； in, Indicates the number of each powder metallurgy part, =1, 2, …, m,m is a positive integer, the standard axis point coordinates are (0,0), , , , represents the coordinates in the upper section of the powder metallurgy part, , , , Represents the coordinates in the lower section of the powder metallurgy part.

3. A method for detecting thermal deformation of powder metallurgy parts according to claim 1, characterized in that: Obtain the coordinates of the measuring axis points of the upper and lower ends of the powder metallurgy parts , , calculate the axis point offset distance of the powder metallurgy part : ; The axis point offset distance The calculation formula is as above.

4. A method for detecting thermal deformation of powder metallurgy parts according to claim 1, characterized in that: Use a laser scanner to measure the lateral distance between the measuring axis points at the upper and lower ends of a powder metallurgy part , measure the distance between the upper and lower sections , calculate the axis offset angle : ; The axis offset angle The calculation formula is as above.

5. The method for detecting thermal deformation of powder metallurgy parts according to claim 1, characterized in that: Get the axis point offset distance of the powder metallurgy part and the axis offset angle , calculate the axis deviation index : ; When the axis offset index When ≥1, it means that the powder metallurgy part has the problem of axial deviation; in, Indicates the maximum allowable axis offset distance for machining powder metallurgy parts. Indicates the maximum allowable axis deviation angle for machining powder metallurgy parts.

6. A method for detecting thermal deformation of powder metallurgy parts according to claim 1, characterized in that: Use a laser scanner to scan the characteristic points on the same horizontal plane of the powder metallurgy part before heating to obtain the height difference between the characteristic points and the standard plane , calculate the flatness coefficient of powder metallurgy parts : ;in, j Indicates the number of each feature point. j =1, 2, …, n,n is a positive integer, Indicates the height difference between all feature points and the standard plane The mean of .

7. A method for detecting thermal deformation of powder metallurgy parts according to claim 1, characterized in that: Measuring the circumference of the upper section of a powder metallurgy part and area , calculate the expansion and contraction coefficient of powder metallurgy parts : ;in, Indicates the standard value of the circumference of a powder metallurgy part. Indicates the standard value of the area of ​​powder metallurgy parts.

8. The method for detecting thermal deformation of powder metallurgy parts according to claim 1, characterized in that: Obtain the flatness coefficient of powder metallurgy parts and expansion coefficient , calculate the surface deformation index of powder metallurgy parts : ； When the surface deformation index + When , it indicates that the surface deformation of the powder metallurgy part is obvious; in, Indicates the surface deformation index of all powder metallurgy specimens in the same batch before heating The mean of Indicates the surface deformation index of all powder metallurgy specimens in the same batch before heating The standard deviation of .

9. A method for detecting thermal deformation of powder metallurgy parts according to claim 1, characterized in that: Obtaining the axis deviation index of powder metallurgy parts and surface deformation index , calculate the thermal deformation index of powder metallurgy parts : ; When the thermal deformation index is ≥1, it indicates that the thermal deformation of the powder metallurgy part is more serious.

10. A powder metallurgy parts thermal deformation detection system, characterized in that: include: The metallurgical parts heating module includes a heating control unit and a temperature uniformity control unit, which are used to accurately control the temperature of the powder metallurgy parts during the heating process to avoid the influence of the uneven temperature distribution of the powder metallurgy parts on the thermal deformation detection results; The axis offset evaluation module includes an offset distance evaluation unit, an offset angle evaluation unit, and an offset comprehensive evaluation unit, which is used to analyze the axis point position and axis angle of the powder metallurgy part to obtain the axis point offset distance. , Axis offset angle and axis misalignment index ; The surface deformation evaluation module includes a flatness evaluation unit, a swelling and shrinkage evaluation unit, and a surface deformation evaluation unit, which is used to analyze the surface flatness, perimeter, and area of ​​powder metallurgy parts to obtain the flatness coefficient of powder metallurgy parts. , expansion coefficient and surface deformation index of powder metallurgy parts ; Thermal deformation evaluation module, including thermal deformation evaluation unit, used to evaluate the axis deviation index of powder metallurgy parts and surface deformation index Comprehensive analysis to obtain thermal deformation index .

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