Full-automatic sample preparation method of impact sample

Abstract

The invention belongs to the technical field of sample impact tests, and discloses a full-automatic sample preparation method of an impact sample, which is characterized in that an original sample is automatically cut by a numerical control sawing machine, a blank is automatically clamped and overturned by combining a multi-station clamping device, and the full-automatic sample preparation method of the impact sample is realized by cooperating with the cooperative work of a visual detection device, a touch probe and a high-precision cutter. The high-precision automatic processing of the blank is realized; sawing, clamping, overturning, machining and detecting functions are integrated in the numerical control sawing machine and the numerical control milling machine, the structure is compact, the occupied space is small, key operations such as automatic recognition and positioning, automatic tool setting, automatic overturning and automatic error correction are completed through the method, the consistency and machining quality of samples are remarkably improved, unattended operation can be achieved, and the working efficiency is improved. Manual intervention is obviously reduced, and labor cost and operation risks are reduced. The space waste and the flow redundancy caused by the traditional multi-equipment series layout are avoided, and the actual requirements of high-efficiency preparation and high-precision control of the current impact sample are practically met.

Description

Technical Field

[0001] The present invention relates to the technical field of sample impact testing, and in particular to a fully automatic sample preparation method for an impact sample. Background Art

[0002] Specimen impact testing assesses the mechanical properties of materials or workpiece specimens by applying impact loads to determine their impact resistance, such as key indicators like brittleness and toughness. This test method has become an essential and fundamental part of quality control in the daily production and new material development processes of my country's steel companies and related research institutes. Almost all metallurgical products must undergo impact performance testing before leaving the factory to ensure their safety and reliability in practical applications. Consequently, the processing and testing of impact specimens has become increasingly onerous, especially in large steel companies, where hundreds or even thousands of specimens must be processed daily.

[0003] However, the current preparation of impact specimens still relies primarily on traditional multi-step machining processes, often requiring the coordinated operation of multiple machine tools of various types. This process is not only complex and space-consuming, but also suffers from low processing efficiency, high labor dependency, and poor specimen consistency, making it difficult to meet current demands for efficient and high-precision specimen preparation. Summary of the Invention

[0004] The purpose of the present invention is to provide a fully automatic sample preparation method for impact specimens, which has a high degree of automation, simple operation, small footprint, high processing efficiency, low dependence on manpower, significantly improving the consistency and processing quality of the specimens, and meeting the current actual needs for efficient preparation and high-precision control of impact specimens.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] The fully automatic sample preparation method of the impact specimen comprises the following steps:

[0007] S1: The required sample preparation parameters are set through the control mechanism, and the original sample is automatically cut by the CNC sawing machine to obtain blanks of multiple standard sizes;

[0008] S2: The plurality of cut blanks are sequentially placed in a plurality of clamping stations of a multi-station clamping device of a CNC milling machine. When the clamping station detects that the blank is in place, the clamping action is automatically performed;

[0009] S3: Starting the visual inspection device and the touch sensor head of the CNC milling machine, the visual inspection device performs an overall scan on the blanks in each of the clamping stations to obtain the initial position information of each of the blanks; at the same time, the touch sensor head, driven by the XYZ three-axis servo motor, sequentially contacts the reference surface and edge of each of the blanks to obtain its three-dimensional coordinate data for size measurement and deviation calibration;

[0010] S4: Based on the data collected by the visual inspection device and the touch sensor head, the tool coordinates are corrected, and the processing starting position and path compensation value of each clamping station are automatically calculated; the tool is driven by the XYZ three-axis servo motor and moves to the upper surface of each blank in sequence according to the optimized path to perform high-precision processing; during the processing, the visual inspection device monitors the tool movement trajectory and the status of the blank in real time;

[0011] S5: After the upper surface of the blank is processed, the multi-station clamping device is driven to flip, so that the blank on each clamping station is flipped 180 degrees in sequence, so that the lower surface faces upward;

[0012] S6: After the flipping is completed, the visual inspection device and the touch sensor are started again to perform position and size verification on the flipped lower surface of the blank, and update the tool processing coordinates and error compensation value accordingly, and then repeat step S4 to perform high-precision processing on the lower surface of the blank and process the notch;

[0013] S7: After all the processing is completed, the multi-station clamping device is adjusted to release the clamping state, and the blanks that have been completed are taken out in sequence.

[0014] Furthermore, the CNC milling machine also includes an automatic loading device and an automatic unloading device. The automatic loading device is arranged on one side of the multi-station clamping device, and can sequentially deliver the blanks cut by the CNC sawing machine into each of the clamping stations; the automatic unloading device is arranged on the opposite side of the automatic loading device, and is used to automatically take out the blanks that have completed sampling in each of the clamping stations.

[0015] Furthermore, the clamping stations on the multi-station clamping device are arranged in a matrix.

[0016] Furthermore, 36 clamping stations are provided on the multi-station clamping device, and the clamping stations are arranged in a matrix of 4 rows in the longitudinal direction and 9 columns in the transverse direction.

[0017] Furthermore, the clamping station includes an electric clamp, a position sensor and a flipping mechanism. The position sensor is installed on the electric clamp to detect whether the blank is in place; the electric clamp is used to clamp the blank, and the flipping mechanism is installed on the multi-station clamping device, and the output end of the flipping mechanism is connected to the electric clamp to drive the electric clamp to flip.

[0018] Furthermore, the multi-station clamping device also includes a main control unit, and the electric clamp, the position sensor and the flipping mechanism are all electrically connected to the main control unit. The main control unit is used to receive information from the position sensor to control the clamping or loosening of the electric clamp, and to control the flipping of the electric clamp through the flipping mechanism.

[0019] Furthermore, the CNC milling machine is provided with a plurality of the visual detection devices and a plurality of the touch sensing heads, and a corresponding visual detection device and a touch sensing head are provided above each of the clamping stations for monitoring the blank on the corresponding clamping station.

[0020] Furthermore, the visual detection device includes a camera and an image processing mechanism, and the camera, the image processing mechanism and the control mechanism are electrically connected.

[0021] Furthermore, the CNC sawing machine includes a fixed-length cutting device and a PLC control unit. The PLC control unit is electrically connected to the fixed-length cutting device and is used to control the fixed-length cutting device to cut the original sample into the blanks of standard size.

[0022] Furthermore, the standard size of the blank is 14 mm×20 mm×60 mm.

[0023] Beneficial effects of the present invention:

[0024] The present invention provides a fully automatic sample preparation method for impact specimens, which automatically cuts the original sample through a CNC sawing machine, automatically clamps and flips the blank in combination with a multi-station clamping device, and cooperates with a visual detection device, a touch sensor head and a high-precision tool to achieve high-precision automated processing of the blank. The above process completes key operations such as automatic identification and positioning, automatic tool setting, automatic flipping and automatic error correction during the whole process of sample preparation of the original sample. The overall system can achieve unattended operation, significantly reducing manual intervention, reducing labor costs and operational risks. The operator only needs to place the original sample and set the sample preparation parameters, and the rest of the processing can be automatically performed throughout the process, which is simple and efficient to operate. The multi-station clamping device is provided with multiple clamping stations, supports the parallel processing of multiple blanks, and has an automatic flipping function, so that the upper and lower surface processing of the blank can be completed continuously in the same equipment, avoiding mid-transfer and manual flipping operations, and effectively improving processing efficiency. The combined use of visual inspection devices and touch sensors enables precise three-dimensional positioning, dimensional inspection, and deviation correction of each blank. Tool paths can also be automatically compensated to ensure highly consistent machining accuracy for each blank, significantly reducing machining deviations caused by clamping errors or material differences, and improving machining consistency and sample quality. Furthermore, during the cutting process, tool status and machining quality can be monitored in real time, enhancing stability and reliability. The fully automated impact specimen preparation method integrates sawing, clamping, flipping, machining, and inspection functions into two types of equipment: CNC saws and CNC milling machines. This compact structure and minimal footprint avoid the space waste and process redundancy associated with traditional multi-device serial layouts, effectively meeting the current demands for efficient impact specimen preparation and high-precision control. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of the fully automatic sample preparation method for impact specimens in the present invention;

[0026] Figure 2 Schematic diagram of a clamping station of a multi-station clamping device in the present invention;

[0027] Figure 3 This is a schematic diagram of the blank structure with a V-shaped notch after processing in the present invention;

[0028] Figure 4 It is a schematic diagram of the blank structure with a U-shaped notch after processing in the present invention.

[0029] In the picture:

[0030] 100, blank;

[0031] 1. Multi-station clamping device; 2. Clamping station. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0033] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0034] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0036] Please refer to Figures 1 to 4 As shown, this embodiment provides a fully automatic method for preparing an impact specimen, comprising the following steps:

[0037] S1: The required sample preparation parameters are set by a control mechanism, and the original sample is automatically cut by a CNC sawing machine to obtain blanks 100 of multiple standard sizes;

[0038] S2: A plurality of cut blanks 100 are sequentially placed into a plurality of clamping stations 2 in the multi-station clamping device 1 of the CNC milling machine. When the clamping station 2 detects that the blank 100 is in place, it automatically performs the clamping action.

[0039] S3: The visual inspection device and the touch sensor head of the CNC milling machine are activated. The visual inspection device performs an overall scan of the blanks 100 in each clamping station 2 to obtain the initial position information of each blank 100. Simultaneously, the touch sensor head, driven by the XYZ three-axis servo motor, sequentially contacts the reference surface and edge of each blank 100 to obtain its three-dimensional coordinate data for size measurement and deviation calibration.

[0040] S4: Based on the data collected by the visual inspection device and the touch sensor head, the tool coordinates are corrected and the machining starting position and path compensation value of each clamping station 2 are automatically calculated; the tool is driven by the XYZ three-axis servo motor and moves to the upper surface of each blank 100 in sequence according to the optimized path to perform high-precision machining; during the machining process, the visual inspection device monitors the tool trajectory and the status of the blank 100 in real time;

[0041] S5: After the upper surface of the blank 100 is processed, the multi-station clamping device 1 is driven to flip, so that the blank 100 on each clamping station 2 is flipped 180 degrees in sequence, so that the lower surface faces upward;

[0042] S6: After the flipping is completed, the visual inspection device and the touch sensor head are started again to check the position and size of the lower surface of the flipped blank 100, and the tool processing coordinates and error compensation values ​​are updated accordingly. Then, step S4 is repeated to perform high-precision processing on the lower surface of the blank 100 and process the notch;

[0043] S7: After all the processing is completed, the multi-station clamping device 1 is adjusted to release the clamping state, and the blanks 100 that have been completed are taken out in sequence.

[0044] The original sample is automatically cut by a CNC sawing machine, and the blank 100 is automatically clamped and flipped in combination with a multi-station clamping device 1. The coordinated work of the visual inspection device, the touch sensor head and the high-precision tool realizes the high-precision automated processing of the blank 100. The above process completes key operations such as automatic identification and positioning, automatic tool setting, automatic flipping and automatic error correction during the whole process of sample preparation of the original sample. The overall system can realize unattended operation, significantly reducing manual intervention, reducing labor costs and operational risks. The operator only needs to place the original sample and set the sample preparation parameters. The rest of the processing can be automatically performed throughout the process, which is simple and efficient to operate. The multi-station clamping device 1 is provided with multiple clamping stations 2, which supports the parallel processing of multiple blanks 100 and has an automatic flipping function. The upper and lower surface processing of the blank 100 can be completed continuously in the same device, avoiding mid-transfer and manual flipping operations, and effectively improving processing efficiency. By combining visual inspection devices with touch sensors, each blank 100 can be precisely positioned in three dimensions, dimensionally inspected, and corrected for deviations. Tool paths can also be automatically compensated to ensure highly consistent machining accuracy for each blank 100, significantly reducing machining deviations caused by clamping errors or material differences, and improving machining consistency and sample quality. Furthermore, during the cutting process, tool status and machining quality can be monitored in real time, enhancing stability and reliability. This fully automated impact specimen preparation method integrates sawing, clamping, flipping, machining, and inspection functions into two types of equipment: a CNC saw and a CNC milling machine. This compact structure and minimal footprint avoid the space waste and process redundancy associated with traditional multi-device serial layouts, effectively meeting the current practical needs for efficient impact specimen preparation and high-precision control.

[0045] For example, the size of the standard-sized blank 100 is 14 mm×20 mm×60 mm, so that each blank 100 can meet the subsequent clamping and milling requirements.

[0046] In some optional embodiments, the CNC sawing machine includes a fixed-length cutting device and a PLC control unit. The PLC control unit is electrically connected to the fixed-length cutting device and is used to control the fixed-length cutting device to cut the original sample into standard-sized blanks 100; wherein, the cutting length parameters are automatically set by the PLC control unit without manual measurement, positioning or intervention, and automatic feeding and automatic cutting can be achieved, supporting batch continuous cutting; the fixed-length cutting device is precisely controlled by the PLC control unit, and its position accuracy and stroke control error are extremely small, which can ensure that the size error of each blank 100 is extremely low.

[0047] In some optional embodiments, the CNC milling machine also includes an automatic loading device and an automatic unloading device. The automatic loading device is arranged on one side of the multi-station clamping device 1, and can sequentially deliver the blanks 100 cut by the CNC sawing machine into each clamping station 2; the automatic unloading device is arranged on the opposite side of the automatic loading device, and is used to automatically take out the blanks 100 that have completed sample preparation in each clamping station 2; wherein, the automatic loading device and the automatic unloading device are respectively arranged on both sides of the multi-station clamping device 1, which can realize the full-process automatic loading and unloading of the blanks 100 without manual intervention in loading and unloading, thereby completing the closed-loop connection of the entire process and improving work efficiency.

[0048] It is understandable that the automatic loading device and the automatic unloading device can be, but are not limited to, a robotic arm, etc., which is not specifically limited here. The robotic arm is a prior art and will not be described in detail here.

[0049] In some embodiments, the clamping stations 2 on the multi-station clamping device 1 are arranged in a matrix. Compared with the linear single-row arrangement, the matrix form is more compact and symmetrical, which reduces the overall size of the equipment and the space occupied. At the same time, it can facilitate the visual inspection device, the tool and the touch sensor head to quickly traverse the positions of each blank 100 along the path, reduce the round-trip time, optimize the path planning, and improve efficiency.

[0050] like Figure 2 As shown, exemplarily, 36 clamping stations 2 are provided on the multi-station clamping device 1 , and the clamping stations 2 are arranged in a matrix of 4 rows in the longitudinal direction and 9 columns in the transverse direction.

[0051] Specifically, the clamping station 2 includes an electric clamp, a position sensor and a flipping mechanism. The position sensor is installed on the electric clamp to detect whether the blank 100 is in place; the electric clamp is used to clamp the blank 100, and the flipping mechanism is installed on the multi-station clamping device 1, and the output end of the flipping mechanism is connected to the electric clamp to drive the electric clamp to flip; wherein, each electric clamp is equipped with a position sensor, which can detect in real time whether the blank 100 is correctly placed in place to prevent problems such as empty clamping, crooked clamping, and misprocessing; the flipping mechanism enables the blank 100 to be automatically flipped 180° in the middle of processing, supports continuous processing of the upper and lower surfaces of the blank 100, without manual flipping or transfer, reducing interruption links, and improving process continuity.

[0052] Furthermore, the multi-station clamping device 1 also includes a main control unit, and the electric clamp, position sensor and flip mechanism are all electrically connected to the main control unit. The main control unit is used to receive information from the position sensor to control the clamping or loosening of the electric clamp, and to control the flipping of the electric clamp through the flip mechanism; wherein, the clamping state of the electric clamp, the information received from the position sensor and the flipping action of the electric clamp can be controlled by the main control unit; when the blank 100 is placed in the electric clamp, the position sensor detects the position of the blank 100 and transmits the information to the main control unit, and the main control unit controls the electric clamp to clamp the blank 100; when the upper surface of the blank 100 is processed, the main control unit uniformly controls each electric clamp to rotate 180° and continue to process the lower surface of the blank 100; if the position sensor does not detect the blank 100, the main control unit prohibits the electric clamp from clamping and flipping, thereby preventing empty clamping and misprocessing. In addition, the main control unit can also preset the clamping force, flip angle and detection sensitivity parameters of each electric clamp to achieve personalized control of the processing strategy.

[0053] Optionally, the electric clamp may be, but is not limited to, a hydraulic wrench or an electric clamp, which is not specifically limited here.

[0054] Among them, the flipping mechanism includes a rotating motor and a swing arm. The rotating motor is installed on the multi-station clamping device 1. The output end of the rotating motor is connected to the swing arm for controlling the rotation of the swing arm. The swing arm is installed on the electric clamp, and the output end of the swing arm is connected to the electric clamp. The swing arm can control the rotation of the electric clamp; the rotating motor is electrically connected to the main control unit so that the main control unit can control its startup.

[0055] like Figure 3 and Figure 4 As shown, optionally, when processing the lower surface of the blank 100, a notch can be further processed on the lower surface according to sample requirements, and the shape of the notch is V-shaped or U-shaped.

[0056] In some embodiments, the CNC milling machine is provided with multiple visual detection devices and multiple touch-sensitive probes, and a corresponding visual detection device and a touch-sensitive probe are arranged above each clamping station 2 for monitoring the blank 100 on the corresponding clamping station 2. In this way, each clamping station 2 is provided with a visual detection device and a touch-sensitive probe, so that independent detection of all stations can be achieved. Each clamping station 2 can complete identification and measurement in parallel, thereby improving detection efficiency; moreover, each set of detection devices only serves its corresponding clamping station 2, with a clear detection range and small interference, thereby avoiding mispositioning, misidentification or cross-station measurement deviation when multiple stations share the detection device.

[0057] Specifically, the visual inspection device includes a camera and an image processing mechanism, and the camera, image processing mechanism and control mechanism are electrically connected; the camera is used to collect image information of the blank 100 on the clamping station 2, and transmit it to the image processing mechanism for analysis and processing. The control mechanism corrects the tool coordinates according to the image processing results, and automatically calculates the processing starting position and path compensation value of each clamping station 2, so as to achieve precise positioning of the blank 100, coordinate calibration and visual tracking of the processing process.

[0058] It should be noted that the XYZ three-axis servo motor is an existing technology and will not be described in detail here. High-precision motion control is achieved through linkage with the tool XYZ three-axis servo motor.

[0059] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A fully automatic method for preparing impact specimens, characterized in that: The following steps are involved: S1: setting the required sample preparation parameters through the control mechanism, and automatically cutting the original sample through the CNC sawing machine to obtain a plurality of standard size blanks (100); S2: The plurality of cut blanks (100) are sequentially placed in a plurality of clamping stations (2) in a multi-station clamping device (1) of a CNC milling machine, and when the clamping station (2) detects that the blank (100) is in place, the clamping action is automatically performed; S3: starting the visual inspection device and the touch sensing head of the CNC milling machine, wherein the visual inspection device performs an overall scan on the blank (100) in each of the clamping stations (2) to obtain initial position information of each of the blanks (100); at the same time, the touch sensing head, driven by the XYZ three-axis servo motor, sequentially contacts the reference surface and edge of each of the blanks (100) to obtain its three-dimensional coordinate data for size measurement and deviation calibration; S4: Based on the data collected by the visual detection device and the touch sensor head, the tool coordinates are corrected, and the processing starting position and path compensation value of each clamping station (2) are automatically calculated; the tool is driven by the XYZ three-axis servo motor and moves to the upper surface of each blank (100) in sequence according to the optimized path to perform high-precision processing; during the processing, the visual detection device monitors the tool running trajectory and the status of the blank (100) in real time; S5: After the upper surface of the blank (100) is processed, the multi-station clamping device (1) is driven to flip, so that the blank (100) on each clamping station (2) is flipped 180 degrees in sequence, so that the lower surface faces upward; S6: After the flipping is completed, the visual inspection device and the touch sensor head are started again to perform position and size verification on the lower surface of the flipped blank (100), and the tool processing coordinates and error compensation values ​​are updated accordingly, and then step S4 is repeated to perform high-precision processing on the lower surface of the blank (100) and process the notch; S7: After all the processing is completed, the multi-station clamping device (1) is adjusted to release the clamping state, and the blanks (100) that have been completed are taken out in sequence.

2. The fully automatic sample preparation method for impact specimens according to claim 1, characterized in that: The CNC milling machine further comprises an automatic loading device and an automatic unloading device. The automatic loading device is arranged on one side of the multi-station clamping device (1) and is capable of sequentially feeding the blanks (100) cut by the CNC sawing machine into each of the clamping stations (2); the automatic unloading device is arranged on the opposite side of the automatic loading device and is used to automatically take out the blanks (100) that have been sampled in each of the clamping stations (2).

3. The fully automatic sample preparation method for impact specimens according to claim 1, characterized in that: The clamping stations (2) on the multi-station clamping device (1) are arranged in a matrix.

4. The fully automatic impact specimen preparation method according to claim 3, characterized in that: The multi-station clamping device (1) is provided with 36 clamping stations (2), and the clamping stations (2) are arranged in a matrix with 4 rows in the longitudinal direction and 9 columns in the transverse direction.

5. The fully automatic method for preparing impact specimens according to claim 3, characterized in that: The clamping station (2) includes an electric clamp, a position sensor and a flipping mechanism, wherein the position sensor is mounted on the electric clamp and is used to detect whether the blank (100) is in place; the electric clamp is used to clamp the blank (100), and the flipping mechanism is mounted on the multi-station clamping device (1), and the output end of the flipping mechanism is connected to the electric clamp to drive the electric clamp to flip.

6. The fully automatic impact specimen preparation method according to claim 5, characterized in that: The multi-station clamping device (1) further comprises a main control unit, the electric clamp, the position sensor and the flipping mechanism are all electrically connected to the main control unit, and the main control unit is used to receive information from the position sensor to control the clamping or loosening of the electric clamp, and to control the flipping of the electric clamp through the flipping mechanism.

7. The fully automatic impact specimen preparation method according to claim 1, characterized in that: The CNC milling machine is provided with a plurality of the visual detection devices and a plurality of the touch sensing heads. A corresponding visual detection device and a touch sensing head are provided above each of the clamping stations (2) for monitoring the blank (100) on the corresponding clamping station (2).

8. The fully automatic impact specimen preparation method according to claim 7, characterized in that: The visual detection device includes a camera and an image processing mechanism, and the camera, the image processing mechanism and the control mechanism are electrically connected.

9. The fully automatic impact specimen preparation method according to claim 1, characterized in that: The numerically controlled sawing machine comprises a fixed-length cutting device and a PLC control unit. The PLC control unit is electrically connected to the fixed-length cutting device and is used to control the fixed-length cutting device to cut the original sample into the blank (100) of standard size.

10. The fully automatic method for preparing impact specimens according to any one of claims 1 to 9, characterized in that: The standard size of the billet (100) is 14mm x 20mm x 60mm.

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