System and method for detecting thermal deformation of powder metallurgy component

Abstract

The invention discloses a thermal deformation detection system and method for a powder metallurgy component, and relates to the technical field of thermal deformation detection, and the method comprises the following steps: filling a detection cavity with inert gas, debugging a resistance furnace, calibrating a temperature control system, clamping a powder metallurgy component sample in the detection cavity, monitoring the internal and surface temperatures of the powder metallurgy component, and adjusting the heating rate. Cooling after heating; measuring coordinates of feature points on three arcs with the standard axis point as the circle center on the sections of the upper end and the lower end of the powder metallurgy component, calculating coordinates of measured axis points of the upper end and the lower end of the powder metallurgy component, calculating the axis point offset distance of the powder metallurgy component, calculating the axis offset angle and calculating the axis offset index; the height difference between the feature points and the standard plane is obtained, the flatness coefficient of the powder metallurgy component is calculated, the expansion and shrinkage coefficient of the powder metallurgy component is calculated, and the surface deformation index of the powder metallurgy component is calculated; and the axis deviation index and the surface deformation index of the powder metallurgy component are obtained, and the thermal deformation index of the powder metallurgy component is calculated.

Description

Technical Field

[0001] The invention relates to the technical field of thermal deformation detection, and in particular to a system and method for detecting thermal deformation of a powder metallurgy part. Background Art

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

[0003] In a Chinese invention application with application publication number CN119188417A, a method for detecting 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 turned on, and calculating the initial center coordinates of the standard ball at each measurement position when the machine tool is turned on; entering the axis rotation 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 during the cycle stage, and calculating the thermal deformation value of the A-axis, judging whether the cooling condition is met, if so, entering the cooling stage, otherwise executing the axis rotation cycle stage; entering the cooling 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, and calculating the thermal deformation value of the A-axis, judging whether the interruption measurement condition is met, if so, the thermal deformation value detection result of the A-axis is obtained, thereby improving the detection accuracy and realizing 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 coordinates of the center of the standard sphere 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. However, it is impossible to effectively judge the surface deformation of the measured part. Only the axial center offset of the measured part is calculated and judged, which cannot effectively and comprehensively reflect the thermal deformation of the measured part.

[0005] To this end, the present invention provides a powder metallurgy parts thermal deformation detection system and method. Summary of the invention

[0006] 1. Technical issues to be resolved In view of the shortcomings of the prior art, the present invention provides a powder metallurgy thermal deformation detection system and method, which accurately controls the heating of the powder metallurgy parts to ensure that they are not affected by improper heating, analyzes the surface deformation of the powder metallurgy parts, and calculates the axis point offset distance of the powder metallurgy parts. , calculate the axis offset angle , calculate the axis deviation index , analyze and calculate the flatness coefficient of powder metallurgy parts by axial deviation , calculate the expansion and contraction coefficient of powder metallurgy parts , calculate the surface deformation index of powder metallurgy parts , and finally calculate the thermal deformation index of the powder metallurgy part The thermal deformation of the powder metallurgy parts is comprehensively evaluated, thereby solving the problems recorded in the background technology.

[0007] (II) Technical solution To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for detecting thermal deformation of powder metallurgy parts, comprising the following steps: 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 .

[0008] Furthermore, the detection chamber is filled with inert gas, and the material of the powder metallurgy part is selected. Ar , Or debug the resistance furnace in a vacuum environment, calibrate the temperature control system to keep the temperature error within 5°C, and ensure the accuracy of temperature control.

[0009] Furthermore, a laser scanner is used 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 part. , , , , , , 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.

[0010] Furthermore, the coordinates of the measuring axis points of the upper and lower ends of the powder metallurgy part are obtained. , , calculate the axis point offset distance of the powder metallurgy part : ; The axis point offset distance The calculation formula is as above.

[0011] Furthermore, a laser scanner is used to measure the lateral distance between the measuring axis points at the upper and lower ends of the 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.

[0012] Furthermore, the axis point offset distance of the powder metallurgy part is obtained 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.

[0013] Furthermore, a laser scanner is used 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 .

[0014] Furthermore, the circumference of the upper section of the powder metallurgy part is measured 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.

[0015] Further, obtain the flatness coefficient of the powder metallurgy part 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.

[0016] 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 .

[0017] Furthermore, the axis deviation index of the powder metallurgy part is obtained and surface deformation index , calculate the thermal deformation index of powder metallurgy parts : ;When the thermal deformation index When ≥1, it indicates that the thermal deformation of the powder metallurgy part is more serious.

[0018] A powder metallurgy parts thermal deformation detection system, comprising: 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 .

[0019] (III) Beneficial effects The present invention provides a powder metallurgy parts thermal deformation detection system and method, which has the following beneficial effects: By filling the test 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 sample in the test cavity, using thermocouples and infrared thermometers to monitor the internal and surface temperature of the powder metallurgy part, adjusting the heating rate so that the temperature difference is less than 30°C, and cooling after heating, it can ensure the precise control of the temperature of the powder metallurgy part during the heating process, and avoid the influence of the uneven temperature distribution of the powder metallurgy part on the thermal deformation test results.

[0020] The laser scanner is used to measure the coordinates of the characteristic points on the 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 , can effectively judge the axial deviation of powder metallurgy parts after thermal deformation, and avoid the failure of the final product due to the axial deviation of powder metallurgy parts.

[0021] 3. 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 It can comprehensively detect and evaluate the surface flatness, circumference and area of ​​powder metallurgy parts, which helps to understand the deformation of the surface of powder metallurgy parts.

[0022] 4. Obtain the axis deviation index of powder metallurgy parts and surface deformation index , calculate the thermal deformation index of powder metallurgy parts , the thermal deformation of powder metallurgy parts can be comprehensively evaluated in terms of axial deviation and surface deformation, which helps to make a more comprehensive judgment on the thermal deformation of powder metallurgy parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a method for detecting thermal deformation of a powder metallurgy part according to the present invention; Figure 2 The present invention is a schematic structural diagram of a powder metallurgy parts thermal deformation detection system. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1 The present invention provides a method for detecting thermal deformation of a powder metallurgy part, comprising the following steps: Step 1: 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 so that the temperature difference is less than 30°C, and cool after heating.

[0026] Step 101: Fill the detection chamber with inert gas and select the material of the powder metallurgy part. Ar , Or debug the resistance furnace in a vacuum environment, calibrate the temperature control system to keep the temperature error within 5°C, and ensure the accuracy of temperature control.

[0027] Step 102, clamp the powder metallurgy sample in the detection chamber, use a thermocouple and an infrared thermometer to monitor the internal and surface temperature of the powder metallurgy part, adjust the heating rate so that the temperature difference is less than 30°C to avoid local overburning leading to inaccurate thermal deformation detection, and cool after heating.

[0028] When using, combine the contents in step 101 to step 102: By filling the test 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 sample in the test cavity, using thermocouples and infrared thermometers to monitor the internal and surface temperature of the powder metallurgy part, adjusting the heating rate so that the temperature difference is less than 30°C, and cooling after heating, it can ensure the precise control of the temperature of the powder metallurgy part during the heating process, and avoid the influence of the uneven temperature distribution of the powder metallurgy part on the thermal deformation test results.

[0029] Step 2: Use a laser scanner to measure the coordinates of the characteristic points on the 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 .

[0030] Step 201: 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 part. , , , , , , 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 cross section of the powder metallurgy part.

[0031] Step 202: Obtain the coordinates of the measuring axis points of the upper and lower ends of the powder metallurgy part , , calculate the axis point offset distance of the powder metallurgy part :

[0032] Step 203: Use a laser scanner to measure the lateral distance between the measuring axis points at the upper and lower ends of the powder metallurgy part. , measure the distance between the upper and lower sections , calculate the axis offset angle :

[0033] Step 204: Obtain 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 an axial deviation problem.

[0034] 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.

[0035] When used, combine the contents in step 201 to step 204: The laser scanner is used to measure the coordinates of the characteristic points on the 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 , can effectively judge the axial deviation of powder metallurgy parts after thermal deformation, and avoid the failure of the final product due to the axial deviation of powder metallurgy parts.

[0036] Step 3: Use a laser scanner to scan the feature points on the same horizontal plane of the powder metallurgy part before heating to obtain the height difference between the feature 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 .

[0037] Step 301: 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 :

[0038] 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 .

[0039] Step 302: Measure the circumference of the upper section of the powder metallurgy part and area , calculate the expansion and contraction coefficient of powder metallurgy parts :

[0040] in, Indicates the standard value of the circumference of a powder metallurgy part. Indicates the standard value of the area of ​​powder metallurgy parts.

[0041] Step 303: Obtain the flatness coefficient of the powder metallurgy part and expansion coefficient , calculate the surface deformation index of powder metallurgy parts :

[0042] When the surface deformation index + When , it indicates that the surface deformation of the powder metallurgy part is obvious.

[0043] 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 .

[0044] When used, combine the contents in step 301 to step 303: By using a laser scanner to scan the characteristic points on the same horizontal plane of the powder metallurgy part before heating, the height difference between the characteristic points and the standard plane is obtained. , 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 , the surface flatness, circumference and area of ​​powder metallurgy parts can be comprehensively tested and evaluated, which helps to understand the deformation of the surface of powder metallurgy parts.

[0045] Step 4: Obtain the axis deviation index of the powder metallurgy part and surface deformation index , calculate the thermal deformation index of powder metallurgy parts .

[0046] Step 401: Obtaining the axis deviation index of the powder metallurgy part and surface deformation index , calculate the thermal deformation index of powder metallurgy parts : ; When the thermal deformation index When ≥1, it indicates that the thermal deformation of the powder metallurgy part is more serious.

[0047] When using, combine the content in step 401: By obtaining the axis deviation index of the powder metallurgy part and surface deformation index , calculate the thermal deformation index of powder metallurgy parts , the thermal deformation of powder metallurgy parts can be comprehensively evaluated in terms of axial deviation and surface deformation, which helps to make a more comprehensive judgment on the thermal deformation of powder metallurgy parts.

[0048] See also Figure 2 The present invention provides a powder metallurgy part thermal deformation detection system, comprising: 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 .

[0049] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product. A person of ordinary skill in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution.

[0050] 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 distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0051] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present 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 cross 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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