CN109342179B - Standard microhardness tester - Google Patents
Standard microhardness tester Download PDFInfo
- Publication number
- CN109342179B CN109342179B CN201811525568.XA CN201811525568A CN109342179B CN 109342179 B CN109342179 B CN 109342179B CN 201811525568 A CN201811525568 A CN 201811525568A CN 109342179 B CN109342179 B CN 109342179B
- Authority
- CN
- China
- Prior art keywords
- focusing
- indentation
- image
- test force
- gear
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/40—Investigating hardness or rebound hardness
- G01N3/42—Investigating hardness or rebound hardness by performing impressions under a steady load by indentors, e.g. sphere, pyramid
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses a standard microhardness meter, and belongs to the field of metering. The invention comprises a test force loading system, an indentation measuring system, a tower platform conversion system and an automatic focusing system which are connected in sequence; the test force loading system, the indentation measuring system, the tower conversion system and the automatic focusing system are all controlled by the control module; when the hardness test is carried out, the test force loading system generates a required test force value, the required test force value is applied to the surface of the sample through the pressure head, the automatic focusing system drives the sample to finish focusing, and the indentation measuring system aligns the obtained indentation to measure through the rotation of the tower platform conversion system. The test lower limit of the invention is 0.0098N, and the invention has the following advantages: (1) the device can enlarge the measuring range of the test force on the premise of ensuring the measurement precision of the test, and (2) the focusing control precision is high, so that the phenomenon of defocusing can be avoided, and the verticality in the focusing process is ensured. The invention can provide practical, effective and reliable technical guarantee for the development of new materials and processes.
Description
Technical Field
The invention belongs to the field of metering, and particularly relates to a standard microhardness meter.
Technical Field
With the development of modern material surface engineering, such as vapor deposition, sputtering, ion implantation, high-energy beam surface modification, thermal spraying, microelectronics, integrated micro-optical electromechanical systems and other fields, the thickness of a sample or a surface modification layer is smaller and smaller, and a microhardness meter which is accurate and reliable in measurement and small in test force value and cannot punch a test sample is urgently needed. At present, the lower limit of the force value of a standard-grade microhardness tester is 0.4903N, the testing force value is larger, and a sample with the characteristics of small size, thinness and the like can be punched through during testing. The lower limit of the force value of the working-grade microhardness meter is 0.0098N, so that the existing test requirements are met, but the test result and the test stability have larger deviation due to loose requirements of various indexes, so that the effective guiding significance cannot be provided. Therefore, it is very urgent to develop a standard microhardness tester with a lower limit of force value of 0.0098N.
Disclosure of Invention
The invention discloses a standard microhardness tester which aims to solve the technical problems that: the standard microhardness tester is provided, measurement of the standard microhardness to the microhardness is realized, the lower test limit is 0.0098N, and the standard microhardness tester has the following advantages: (1) under the condition that the test force range is (0.0098-9.8) N, the force value precision can be ensured as follows: when the test force value F is more than 1.961, the error of the test force is +/-0.1%; when the test force value F is less than or equal to 1.961, the error of the test force is +/-0.5 percent; (2) the focusing control precision is high, the defocusing phenomenon can be avoided, and the verticality in the focusing process is ensured. The invention can provide practical, effective and reliable technical guarantee for the development of new materials and processes.
The purpose of the invention is realized by the following technical scheme.
The invention discloses a standard microhardness tester which comprises a test force loading system, an indentation measuring system, a tower platform conversion system, an automatic focusing system and a control module. The test force loading system, the indentation measuring system, the tower conversion system and the automatic focusing system are all controlled by the control module, the test force loading system is connected with the indentation measuring system through the tower conversion system, and the three systems and the automatic focusing system are installed on the equipment body together.
When the hardness test is carried out, the test force loading system generates a required test force value, the required test force value is applied to the surface of the sample through the pressure head, the automatic focusing system drives the sample to finish focusing, and the indentation measuring system aligns the obtained indentation to measure through the rotation of the tower platform conversion system.
The tower conversion system is used for converting the force value loading system and the indentation measuring system.
Furthermore, the test force loading system is used for realizing the variable load and loading of the test force and comprises a load device seat, a variable load hand wheel, a transmission rod, an indexing disc, a load driving gear, a limiter, a change gear, a sector gear, a spur rack, a sliding plate, a ball linear guide rail, a load bowl and a weight group. The variable-load hand wheel is connected with a load driving gear through a transmission rod, an indexing disc is arranged on the transmission rod, the load driving gear is connected with a limiter, the load driving gear is meshed with a sector gear through a change gear, the sector gear is connected with a spur rack, the spur rack is connected with a load bowl through a sliding plate, a weight group is arranged in the load bowl, and the sliding plate is connected with a load device seat through a ball linear guide rail.
Furthermore, the indentation measuring system is used for collecting and measuring an indentation image and comprises a light source, an objective lens mounting surface, a primary reflector, a spectroscope, an imaging surface, a reticle, an eyepiece lens, a steering reflector, a CCD camera target surface and an indentation image measuring module. Wherein, the light source is used for the light field of illumination, makes the observation more clear, measures more accurately. The objective lens mounting surface is the initial reference surface of the optical path imaging system mechanical cylinder length, and the objective lens is used for amplifying the indentation. The main reflector is used for changing the direction of an imaging light path. The beam splitter is used for reflecting the light source to the primary reflector to reach the object plane and transmitting the primary reflector imaging light path light beam to the imaging plane. The imaging surface is used for receiving and presenting microhardness indentation images, the imaging surface does not participate in working of the reticle and is provided with two parallel scribed lines when a CCD camera is used for observing and measuring, the rotation of 360 degrees is realized and is used for respectively measuring the lengths of the diagonal lines of the indentations in the horizontal direction and the vertical direction, and the imaging surface does not participate in imaging when the CCD camera is used for observing and measuring. The eyepiece is a magnifying eyepiece lens and is used for observing and measuring the diagonal length of the micro-hardness indentation. The steering reflector is divided into two conditions according to the reality, when a CCD camera is used for observation and measurement, the imaging light beam penetrating through the spectroscope is steered and projected to the target surface of the CCD camera, and when an eyepiece is used for measurement and observation, the steering reflector does not participate in imaging work. The CCD camera target surface is used for receiving and presenting microhardness indentation images, and the indentation image measuring module is used for automatically measuring indentations and calculating to obtain hardness values.
Preferably, the dimensional parameters and positional relationships of the components of the indentation measurement system are as follows: the light source is a 5W multipoint LED area light source consisting of 15 wafers. The objective lens is a flat field objective lens with a mechanical cylinder length of 160mm, a numerical aperture of 0.65 and an amplification factor of 40. The objective lens mounting surface is a starting reference surface of the mechanical cylinder length of the optical path imaging system. The angle between the main reflector and the objective lens mounting surface is 55 degrees, and the center point of the main reflector is 20mm away from the objective lens mounting surface. The included angle between the spectroscope and the objective lens mounting surface is 55 degrees, and the center point of the spectroscope is 22mm away from the center point of the primary reflector. The imaging surface is perpendicular to the optical path direction of the primary reflector and is 140mm away from the central point of the primary reflector. The reticle is positioned on the other side of the imaging surface and is tightly connected with the imaging surface. The eyepiece is an eyepiece lens with the magnification of 10 times. The included angle between the steering reflector and the objective lens mounting surface is 55 degrees, and the center point of the steering reflector is 50mm away from the center point of the primary reflector. The target surface of the CCD camera is positioned right above the light path of the steering reflector and is 90mm away from the central point of the steering reflector.
Further, an indentation measurement module of the indentation measurement system is used for realizing measurement of the size of the indentation, and the realization method comprises the following steps:
firstly, a regular quadrangle indentation image projected by a regular rectangular pyramid on a sample is projected onto a CCD through an optical lens barrel.
And secondly, defining the obtained indentation image as a 256-level gray image map, and dividing the image into 0-255 gray levels. 0 is black, 255 is white, and the intermediate values are different gradations.
And thirdly, processing the 256-level gray level image obtained in the second step into a binary black-and-white image of 0-1 through gray level light-and-dark contrast according to a set gray level threshold value because the indentation part is darker than the background.
And fourthly, identifying the indentation and the background sundries, and comparing and distinguishing the X/Y length of one image according to the binary black-white image obtained in the third step. If the difference of X/Y is less than 10%, the image is judged to be an indentation, and the rest is omitted.
And fifthly, selecting a scanning interval for the indentation judged in the fourth step according to the precision requirement. And (4) defining a scanning interval by using a yellow frame line according to the precision requirement, and measuring a target small area.
Sixthly, scanning the target small area in the frame line area obtained in the fifth step point by point and line by line, namely obtaining the number of diagonal pixel points of X and Y of the indentation, Xpixel and Ypixel
And seventhly, calibrating the factors of the pixels and the length of the whole fluorescent screen in advance. Namely, the X axis: 1 pixel (pixel) ═ Lx (length), Y axis: 1 pixel (Ly (length))
Eighthly, calibrating the factors of the pixel and the length of the whole fluorescent screen in advance, and performing corresponding operation on the Xpixel and the Ypixel to obtain the real lengths of d1 and d2
The ninth step, substituting the average value d of d1 and d2 into HV 1.8544F/d2Wherein F is the test force/kgf, d is the average value of the indentation diagonal/mm, and the hardness value is obtainedHV。
Furthermore, the automatic focusing system is used for automatic focusing of indentation, improving the control precision of manual focusing, ensuring the lifting verticality and avoiding the phenomenon of defocusing; the auto-focusing system includes: the device comprises a workbench, a focusing gear, a small belt wheel, a lifting motor base, a stepping motor, a connecting shaft, a conveying belt, a large belt wheel, a hand wheel, a direction guide rail, a direction bearing, a focusing base, a ball bearing, a 45-degree spiral gear, a focusing shaft sleeve, a focusing shaft, a driving box and an automatic focusing module.
The method is divided into a manual mode or an automatic focusing mode according to actual use conditions, wherein the manual mode comprises the following steps: the hand wheel drives the focusing gear to rotate, and the focusing gear rotates through meshing with the 45-degree spiral gear to enable the focusing shaft to move up and down, so that the workbench above the focusing shaft is driven to move up and down to complete focusing. Automatic mode: the automatic focusing module controls the driving box, the driving box drives the stepping motor to rotate, so that the small belt wheel connected with the stepping motor through the connecting shaft is driven to rotate, the large belt wheel connected with the small belt wheel through the conveying belt is further driven to rotate, the large belt wheel drives the focusing gear to rotate, the focusing gear turns through meshing with the 45-degree spiral gear, so that the focusing shaft moves up and down, and the workbench above the focusing shaft is driven to move up and down to complete focusing.
The automatic focusing module is used for realizing automatic focusing control, and the realization method comprises the following steps:
firstly, carrying out primary indentation image focusing collection on the pressed indentation, and finding out the next more accurate focusing range through calculation; the primary indentation step distance is (+ -10 to +/-400) mu m.
Secondly, focusing and collecting secondary indentation images within a more accurate focusing range obtained after primary focusing to obtain an accurate focusing range; the secondary indentation step distance is (+/-1 to +/-9) mu m.
And thirdly, carrying out focusing collection on the final indentation image in a focal plane in an accurate focusing range obtained after secondary focusing so as to obtain the final accurate, clear and measurable indentation image. The final indentation step distance is (+ -0.4- + -0.9) mu m.
And fourthly, finding the focal plane obtained in the third step, after obtaining an accurate, clear and measurable indentation image, adjusting the state to an under-focus state, and then adjusting the state back to an parfocalization state, namely, the workbench moves downwards by the distance of the step pitch set in the third step and moves upwards, so that the lower edge of the thread of the focusing shaft moving up and down is always above the upper edge of the thread of the focusing shaft sleeve, and the defocusing phenomenon caused by the increase of the test force and the influence of gravity is eliminated.
Preferably, in order to eliminate pitch clearance and idle stroke in the process of focusing and reversing and facilitate control, the step motor needs to be subjected to preset stepping focusing operation firstly after reversing. The method of the preset step is as follows: the pitch is α μm, the magnification factor in motor control focusing is x, and the number of pulses of the motor for 360 ° per rotation is β, so that the distance δ corresponding to each pulse of the motor is α/(x · β), the idle stroke gap by the pitch is γ μm, and γ/δ is a number of pulses required to eliminate the gap.
Furthermore, the test force loading system and the indentation measuring system are connected through a tower and are jointly carried on the main board.
Furthermore, the automatic focusing system, the test force loading system, the indentation measuring system and the tower conversion system are jointly carried on the machine body.
Further, the control module is used for controlling the operation of the equipment.
Has the advantages that:
1. the invention discloses a standard microhardness meter, which is used for measuring standard microhardness, expanding the measuring range of test force on the premise of ensuring the test measuring precision, and through test verification, the range of the test force is (0.0098-9.8) N, and the force value precision is as follows: when the test force value F is more than 1.961, the error of the test force is +/-0.1%; when the test force value F is less than or equal to 1.961, the error of the test force is +/-0.5 percent. The indentation measurement precision is +/-0.2 mu m, and the hardness indication error is +/-3 percent.
2. According to the standard microhardometer disclosed by the invention, the ruler strip and the ball linear guide rail are additionally arranged in the test force loading system, so that the curve load changing mode of the existing equipment by adopting a lever structure is changed into linear load changing, and the condition that each weight in a weight group is not concentric due to load changing is changed, thus the test force error is reduced, and the stability of the test force loading system is improved.
3. The invention discloses a standard microhardness tester.A standard objective with a mechanical cylinder length of 160mm is selected in an indentation measuring system, so that the problem that the existing microhardness tester indentation measuring system can only use a non-standard objective lens with a mechanical cylinder length of 210mm is solved, the imaging quality is improved, and the production cost is reduced.
4. The invention discloses a standard microhardness tester.A manual focusing module is added in an indentation measuring system to solve the problems of poor control precision of manual focusing and errors caused by operators, and the automatic measurement of the size of an indentation is finished by utilizing the indentation automatic measuring module; the automatic focusing module is used for avoiding the defocusing phenomenon; a direction guide rail and a fixed direction bearing are added on the focusing shaft to ensure the verticality of the focusing mechanism.
5. In the indentation measurement system, a light source is changed from a conventional 50W halogen lamp into a 5W multipoint LED surface light source consisting of 15 wafers, the brightness is high, and the straightness of light is good, so that the visual field becomes clearer, and the imaging quality is improved; the 5W multipoint LED area light source used in the invention has low power, can eliminate the fault of the penetration of the mainboard, and prolongs the service life.
Drawings
FIG. 1 is a schematic diagram of a standard microhardness tester of the present invention;
FIG. 2 is a schematic diagram of a test force loading system for a standard microhardness tester of the present invention;
FIG. 3 is a schematic diagram of an indentation measurement system for a standard microhardness tester according to the present invention;
FIG. 4 is a schematic diagram A of the autofocus system of a standard microhardness tester of the present invention;
FIG. 5 is a schematic diagram B of the autofocus system of a standard microhardness tester of the present invention;
FIG. 6 is a schematic diagram C of the autofocus system of a standard microhardness tester of the present invention;
FIG. 7 is a schematic representation of hardness indentations produced by a standard microhardness tester of the present invention;
FIG. 8 is a binary black and white image of a hardness indentation produced by a standard microhardness tester of the present invention;
FIG. 9 is a schematic representation of an indentation with background inclusions produced by a standard microhardness tester of the present invention, wherein: fig. 9A is a schematic diagram of an indentation with a scratch, fig. 9B is a binary black-and-white image of the indentation with the scratch, fig. 9C is a schematic diagram of an indentation with rust, and fig. 9D is a binary black-and-white image of the indentation with rust;
FIG. 10 is a schematic diagram of an indentation showing a scan measurement interval when a standard microhardness tester of the present invention is automatically measuring, wherein: fig. 10A is a schematic diagram of the indentation in the scanning measurement interval, and fig. 10B is a binary black-and-white image of the indentation in the scanning measurement interval.
Wherein: 1-load device seat, 2-variable load hand wheel, 3-transmission rod, 4-graduated disk, 5-load driving gear, 6-position limiter, 7-direction changing gear, 8-sector gear, 9-spur rack, 10-slide plate, 11-ball linear guide rail, 12-load bowl, 13-weight group, 14-ocular, 15-reticle, 16-imaging surface, 17-CCD camera target surface, 18-steering reflector, 19-spectroscope, 20-main reflector, 21-light source, 22-objective mounting surface, 23-objective, 24-workbench, 25-focusing gear, 26-small belt wheel, 27-lifting motor seat, 28-stepping motor, 29-connecting shaft, 30-transmission belt, 31-large belt wheel, 32-hand wheel, 33-direction guide rail, 34-direction bearing, 35-focusing base, 36-ball bearing, 37-45 degree helical gear, 38-helical gear, 39-focusing gear, 39-shaft sleeve, 40-focusing axis.
Detailed Description
The present invention will be described in further detail below with reference to the accompanying drawings by way of specific embodiments.
Example 1:
as shown in fig. 1, the standard microhardness tester disclosed in this embodiment includes a test force loading system, an indentation measuring system, a turret switching system, an auto-focusing system, and a control module. The test force loading system, the indentation measuring system, the tower conversion system and the automatic focusing system are all controlled by the control module, the test force loading system is connected with the indentation measuring system through the tower conversion system, and the three systems and the automatic focusing system are installed on the equipment body together.
When the hardness test is carried out, the test force loading system generates a required test force value, the required test force value is applied to the surface of the sample through the pressure head, the automatic focusing system drives the sample to finish focusing, and the indentation measuring system aligns the obtained indentation to measure through the rotation of the tower platform conversion system.
The tower conversion system is used for converting the force value loading system and the indentation measuring system.
The test force loading system is connected with the indentation measuring system through a tower and is carried on the main board together.
The automatic focusing system, the test force loading system, the indentation measuring system and the tower conversion system are jointly carried on the machine body.
The control module is used for controlling the equipment to operate.
As shown in fig. 2, the test force loading system is used for realizing the load change and loading of the test force, and comprises a load device seat 1, a load change hand wheel 2, a transmission rod 3, an indexing disc 4, a load driving gear 5, a limiter 6, a change gear 7, a sector gear 8, a spur rack 9, a sliding plate 10, a ball linear guide rail 11, a load bowl 12 and a weight group 13. The variable-load hand wheel 2 is connected with a load driving gear 5 through a transmission rod 3, an indexing disc 4 is arranged on the transmission rod 3, the load driving gear 5 is connected with a limiter 6, the load driving gear 5 is meshed with a sector gear 8 through a change gear 7, the sector gear 8 is connected with a spur rack 9, the spur rack 9 is connected with a load bowl 12 through a sliding plate 10, a weight group 13 is arranged in the load bowl 12, and the sliding plate 10 is connected with a load device seat 1 through a ball linear guide rail 11.
As shown in fig. 3, the indentation measuring system is used for collecting and measuring an indentation image, and includes a light source 21, an objective 23, an objective mounting surface 22, a primary reflector 20, a beam splitter 19, an imaging surface 16, a reticle 15, an eyepiece 14, a steering reflector 18, and a CCD camera target surface 17. The light source 21 is a 5W multipoint LED surface light source composed of 15 wafers. The objective lens 23 is a flat field objective lens with a mechanical cylinder length of 160mm, a numerical aperture of 0.65 and an amplification factor of 40. The objective lens mounting surface 22 is a starting reference surface of the mechanical cylinder length of the optical path imaging system. The angle between the primary reflector 20 and the objective lens mounting surface 22 is 55 degrees, and the center point of the primary reflector is 2220mm away from the objective lens mounting surface. The beam splitter 19 forms an angle of 55 degrees with the objective lens installation surface 22, and the center point of the beam splitter is 22mm away from the center point of the primary reflector 20. The imaging plane 16 is perpendicular to the optical path direction of the primary mirror 20 and is 140mm from the center point of the primary mirror 20. The reticle 15 is located on the other side of the imaging plane and is closely attached to the imaging plane. The eyepiece 14 is an eyepiece lens with a magnification of 10 times. The steering mirror 18 makes an angle of 55 degrees with the objective mounting surface 22, and its center point is 50mm from the center point of the primary mirror 20. The target surface of the CCD camera is positioned right above the light path of the steering reflector and is 90mm away from the central point of the steering reflector.
The indentation measurement module of the indentation measurement system is used for realizing measurement of the size of an indentation, and the specific realization steps are as follows:
first, as shown in fig. 7, an impression image of a nearly regular quadrangle projected on a regular rectangular pyramid on a sample is projected onto a CCD through an optical tube.
And secondly, defining the obtained indentation image as a 256-level gray image map, and dividing the image into 0-255 gray levels. 0 is black, 255 is white, and the intermediate values are different gradations.
Third, since the indented portion is usually darker than the background, the 256-level gray image obtained in the second step is processed into a binary black-and-white image of 0 to 1 by gray level contrast according to a set gray level threshold, as shown in fig. 8.
And a fourth step of recognizing the indentations and the background foreign matter, and comparing and distinguishing the X/Y length of one image according to the binary black-and-white image obtained in the third step, as shown in FIG. 9. If the difference of X/Y is less than 10%, the image is judged to be an indentation, and the rest is omitted.
And a fifth step, as shown in fig. 10, of selecting a scanning interval for the indentation determined in the fourth step according to the accuracy requirement. And (4) defining a scanning interval by using a frame line according to the precision requirement, and measuring a target small area.
And sixthly, scanning the target small area in the frame line area obtained in the fifth step point by point line by line, namely obtaining the number of diagonal pixel points of X and Y of the indentation, Xpixel and Ypixel.
And seventhly, calibrating the factors of the pixels and the length of the whole fluorescent screen in advance. Namely, the X axis: 1 pixel (pixel) ═ Lx (length), Y axis: 1 pixel (Ly) is equal to Ly (length).
And eighthly, calibrating the factors of the pixels and the length of the whole fluorescent screen in advance, and performing corresponding operation on the Xpixel and the Ypixel to obtain the real lengths of d1 and d 2.
The ninth step, substituting the average value d of d1 and d2 into HV 1.8544F/d2Wherein F is the test force/kgf, and d is the average value of the indentation diagonal/mm, to obtain the hardness value HV.
As shown in fig. 4, 5 and 6, the automatic focusing system is used for automatic focusing of indentation, improving manual focusing control precision, ensuring lifting verticality and avoiding a defocusing phenomenon; the automatic focusing system comprises a workbench 24, a focusing gear 25, a small belt wheel 26, a lifting motor base 27, a stepping motor 28, a connecting shaft 29, a conveying belt 30, a large belt wheel 31, a hand wheel 32, a direction guide rail 33, a direction bearing 34, a focusing base 35, a ball bearing 36, a 45-degree spiral gear 37, a spiral gear 38, a focusing shaft sleeve 39, a focusing shaft 40, a driving box and an automatic focusing module.
The method is divided into a manual mode or an automatic focusing mode according to actual use conditions, wherein the manual mode comprises the following steps: the hand wheel 32 drives the focusing gear 25 to rotate, the focusing gear 25 rotates through meshing with the 45-degree spiral gear 37, so that the focusing shaft 40 moves up and down, and the workbench 24 above the focusing shaft 40 is driven to move up and down to complete focusing. Automatic mode: the automatic focusing module controls the driving box, the driving box drives the stepping motor 28 to rotate, so as to drive the small belt wheel 26 connected with the stepping motor 28 through the connecting shaft 29 to rotate, further drive the large belt wheel 31 connected with the small belt wheel 26 through the conveying belt 30 to rotate, the large belt wheel 31 drives the focusing gear 25 to rotate, the focusing gear 25 rotates through the meshing steering of the 45-degree spiral gear 37, so that the focusing shaft 40 moves up and down, and the workbench 24 above the focusing shaft 40 is driven to move up and down to complete focusing.
The automatic focusing module is used for realizing automatic focusing control, and comprises the following specific implementation steps:
firstly, carrying out primary indentation image focusing collection with the step pitch of +/-10 mu m on the pressed indentation, and finding out the next more accurate focusing range through calculation.
And secondly, carrying out secondary indentation image focusing collection with the step pitch of +/-1 mu m in a more accurate focusing range obtained after primary focusing to obtain an accurate focusing range.
And thirdly, focusing and collecting the final indentation image with the step pitch of +/-0.4 mu m within the accurate focusing range obtained after secondary focusing so as to obtain the accurate, clear and measurable indentation image.
And fourthly, finding the focal plane obtained in the third step, after obtaining the accurate, clear and measurable indentation image, firstly adjusting the state to the under-focus state, then adjusting the state back to the parfocal state found in the third step, firstly moving the workbench 24 downwards by the distance of the step distance set in the third step, and moving the workbench 24 upwards, so that the lower edge of the thread of the focusing shaft 40 which moves up and down is always above the upper edge of the thread of the focusing shaft sleeve 39, the defocusing phenomenon which is caused along with the increase of the test force and the influence of gravity is eliminated, and the accurate, clear and measurable indentation image which is free of the defocusing phenomenon is obtained finally.
In order to eliminate the pitch clearance in the process of focusing and reversing, 27 pulses of stepping are firstly carried out on the motor after reversing and then focusing is carried out, so that the influence of idle stroke caused by the pitch clearance after reversing on subsequent focusing is reduced.
Through detection, the technical indexes of the standard microhardness tester disclosed by the embodiment are as follows:
test force value detection data table
Detection data table of indentation measurement system
Hardness meter indicating value detection data table
The test result shows that the standard microhardness meter disclosed by the embodiment completely meets the requirements of related verification regulations, the test force range is (0.0098-9.8) N, and the force value precision is as follows: when the test force value F is more than 1.961, the error of the test force is +/-0.1%; when the test force value F is less than or equal to 1.961, the error of the test force is +/-0.5 percent. The indentation measurement precision is +/-0.2 mu m, and the hardness indication error is +/-3 percent.
The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (9)
1. A standard microhardness meter, comprising: the device comprises a test force loading system, an indentation measuring system, a tower conversion system and an automatic focusing system which are connected in sequence; the test force loading system, the indentation measuring system, the tower conversion system and the automatic focusing system are all controlled by the control module, the test force loading system is connected with the indentation measuring system through the tower conversion system, and the three systems and the automatic focusing system are installed on the equipment body together;
when a hardness test is carried out, the test force loading system generates a required test force value, the required test force value is applied to the surface of the sample through the pressure head, the automatic focusing system drives the sample to finish focusing, and the indentation measuring system aligns the obtained indentation to measure through the rotation of the tower platform conversion system;
the tower platform conversion system is used for converting the force value loading system and the indentation measuring system;
the test force loading system is used for realizing the variable load and loading of test force and comprises a load device seat (1), a variable load hand wheel (2), a transmission rod (3), an indexing disc (4), a load driving gear (5), a limiter (6), a change gear (7), a sector gear (8), a spur rack (9), a sliding plate (10), a ball linear guide rail (11), a load bowl (12) and a weight group (13); the variable-load hand wheel (2) is connected with a load driving gear (5) through a transmission rod (3), an indexing disc (4) is arranged on the transmission rod (3), the load driving gear (5) is connected with a limiter (6), the load driving gear (5) is meshed with a sector gear (8) through a change gear (7), the sector gear (8) is connected with a spur rack (9), the spur rack (9) is connected with a load bowl (12) through a sliding plate (10), a weight group (13) is arranged in the load bowl (12), and the sliding plate (10) is connected with a load device seat (1) through a ball linear guide (11).
2. A standard microhardness tester according to claim 1, wherein: the indentation measuring system is used for collecting and measuring an indentation image and comprises a light source (21), an objective lens (23), an objective lens mounting surface (22), a primary reflector (20), a spectroscope (19), an imaging surface (16), a reticle (15), an ocular lens (14), a steering reflector (18), a CCD camera target surface (17) and an indentation image measuring module; the light source (21) is used for illuminating a light field, so that observation is clearer and measurement is more accurate; the objective lens (23) is used for amplifying the indentation; the objective lens mounting surface (22) is a starting reference surface of the optical path imaging system mechanical cylinder length; the main reflector (20) is used for changing the imaging light path direction; the beam splitter (19) is used for reflecting the light source (21) to the primary reflector (20) to reach the object plane on one hand, and is used for transmitting the imaging optical path beam of the primary reflector (20) to the imaging plane (16) on the other hand; the imaging surface (16) is used for receiving the image presenting the microhardness indentation, and the imaging surface (16) does not participate in imaging work when a CCD camera is used for observing and measuring; the dividing plate (15) is provided with two parallel scribed lines, and can rotate 360 degrees to respectively measure the length of the diagonal line of the indentation in the horizontal direction and the indentation in the vertical direction, and the dividing plate does not participate in imaging work when a CCD camera is used for observing and measuring; the eyepiece (14) is a magnifying eyepiece lens and is used for observing and measuring the diagonal length of the microhardness indentation; the steering reflector (18) is divided into two conditions according to the reality, when a CCD camera is used for observation and measurement, the imaging light beam transmitted through the spectroscope (19) is steered and projected to a target surface (17) of the CCD camera, and when an eyepiece (14) is used for measurement and observation, the steering reflector (18) does not participate in imaging work; the CCD camera target surface (17) is used for receiving an image presenting microhardness indentation.
3. A standard microhardness tester according to claim 2, wherein: the preferable dimensional parameters and the position relationship of the parts of the indentation measuring system are as follows: the light source (21) is a 5W multipoint LED surface light source consisting of 15 wafers; the objective lens (23) is a flat field objective lens with a mechanical cylinder length of 160mm, a numerical aperture of 0.65 and an amplification factor of 40 times; the objective lens mounting surface (22) is a starting reference surface of the optical path imaging system mechanical cylinder length; the included angle between the main reflector (20) and the objective lens mounting surface (22) is 55 degrees, and the center point of the main reflector is 20mm away from the objective lens mounting surface (22); the beam splitter (19) and the objective lens mounting surface (22) form an included angle of 55 degrees, and the center point of the beam splitter is 22mm away from the center point of the primary reflector (20); the imaging surface (16) is vertical to the optical path direction of the main reflector (20) and is 140mm away from the central point of the main reflector (20); the reticle (15) is positioned on the other side of the imaging surface (16) and is tightly connected with the imaging surface (16); the eyepiece (14) is an eyepiece lens with the magnification of 10 times; an included angle of 55 degrees is formed between the steering reflector (18) and the objective lens mounting surface (22), and the center point of the steering reflector is 50mm away from the center point of the main reflector (20); the CCD camera target surface (17) is positioned right above the light path of the steering reflector (18) and is 90mm away from the central point of the steering reflector (18).
4. A standard microhardness tester according to claim 2 or claim 3, wherein: the indentation measuring module of the indentation measuring system is used for realizing the automatic measurement of the size of the indentation, and the realization method comprises the following steps,
firstly, projecting an orthoquadrangular impression image projected by an orthoquadrangular pyramid on a sample to a CCD (charge coupled device) through an optical lens cone;
secondly, defining the obtained indentation image as a 256-level gray image, and dividing the image into 0-255 gray levels; 0 is black, 255 is white, the intermediate values are different gray levels;
thirdly, because the indentation part is darker than the background, the 256-level gray level image obtained in the second step is processed into a binary black-and-white image of 0-1 through gray level light-dark contrast according to a set gray level threshold value;
fourthly, identifying the indentation and the background sundries, and comparing and distinguishing the X/Y length of one image according to the binary black-white image obtained in the third step; if the difference value of X/Y is less than 10%, the image is judged to be an indentation, and the rest is omitted;
fifthly, selecting a scanning interval for the indentation judged in the fourth step according to the precision requirement; according to the precision requirement, a yellow frame line is used for defining a scanning interval, and target small area measurement is carried out;
sixthly, scanning the target small area in the frame line area obtained in the fifth step point by point and line by line, namely obtaining the number of diagonal pixel points of X and Y of the indentation, Xpixel and Ypixel;
seventhly, calibrating the factors of the pixels and the length of the whole fluorescent screen in advance; namely, the X axis: 1 pixel (pixel) ═ Lx (length), Y axis: 1 pixel (Ly (length))
Eighthly, calibrating the factors of the pixel and the length of the whole fluorescent screen in advance, and performing corresponding operation on the Xpixel and the Ypixel to obtain the real lengths of d1 and d2
The ninth step, substituting the average value d of d1 and d2 into HV 1.8544F/d2Wherein F is a test force/kgf and d is an average value of diagonal lines of the indentation/mm, to obtain a hardness value HV.
5. A standard microhardness tester according to claim 2 or claim 3, wherein: the automatic focusing system is used for automatic focusing of the indentation, improving the manual focusing control precision, ensuring the lifting verticality and avoiding the defocusing phenomenon; the automatic focusing system comprises a workbench (24), a focusing gear (25), a small belt wheel (26), a lifting motor base (27), a stepping motor (28), a connecting shaft (29), a conveying belt (30), a large belt wheel (31), a hand wheel (32), a direction guide rail (33), a direction bearing (34), a focusing base (35), a ball bearing (36), a 45-degree spiral gear (37), a spiral gear (38), a focusing shaft sleeve (39), a focusing shaft (40) driving box and an automatic focusing module;
the method is divided into a manual mode or an automatic focusing mode according to actual use conditions, wherein the manual mode comprises the following steps: the hand wheel (32) drives the focusing gear (25) to rotate, the focusing gear (25) rotates through meshing with the 45-degree spiral gear (37) to enable the focusing shaft (40) to move up and down, and therefore the workbench (24) above the focusing shaft (40) is driven to move up and down to finish focusing; automatic mode: the automatic focusing module controls the driving box, the driving box drives the stepping motor (28) to rotate, so that the small belt wheel (26) connected with the stepping motor (28) through the connecting shaft (29) is driven to rotate, the large belt wheel (31) connected with the small belt wheel (26) through the conveying belt (30) is further driven to rotate, the large belt wheel (31) drives the focusing gear (25) to rotate, the focusing gear (25) rotates to enable the focusing shaft (40) to move up and down through meshing and steering with the 45-degree spiral gear (37), and the workbench (24) above the focusing shaft (40) is driven to move up and down to finish focusing.
6. A standard microhardness tester according to claim 5, wherein: the automatic focusing module is used for realizing automatic focusing control, and the realizing method comprises the following steps,
firstly, carrying out primary indentation image focusing acquisition with the step pitch of +/-10 to +/-400 mu m on the pressed indentation, and finding out the next more accurate focusing range through calculation;
secondly, carrying out secondary indentation image focusing collection with the step pitch of +/-1 to +/-9 mu m in a more accurate focusing range obtained after primary focusing to obtain an accurate focusing range;
thirdly, focusing and collecting the final indentation image with the step pitch of +/-0.4 to +/-0.9 mu m within the accurate focusing range obtained after secondary focusing so as to obtain an accurate, clear and measurable indentation image;
and fourthly, finding the focal plane obtained in the third step, after obtaining an accurate, clear and measurable indentation image, firstly adjusting the state to an under-focus state, and then adjusting the state back to the parfocal state found in the third step, namely, the working table moves downwards firstly by the distance of the step pitch set in the third step and then moves upwards, so that the lower edge of the thread of the focusing shaft (40) moving up and down is always above the upper edge of the thread of the focusing shaft sleeve (39), the defocusing phenomenon occurring along with the increase of the test force and the influence of gravity is eliminated, and the accurate, clear and measurable indentation image without the defocusing phenomenon is obtained finally.
7. A standard microhardness tester according to claim 6, wherein: in order to eliminate pitch clearance and idle stroke in the process of focusing and reversing and facilitate control, a stepping motor needs to perform preset stepping focusing operation after reversing; the method of the preset step is as follows: the pitch is α μm, the magnification factor in motor control focusing is x, and the number of pulses of the motor for 360 ° per rotation is β, so that the distance δ corresponding to each pulse of the motor is α/(x · β), the idle stroke gap by the pitch is γ μm, and γ/δ is a number of pulses required to eliminate the gap.
8. A standard microhardness tester according to claim 2 or claim 3, wherein: the test force loading system is connected with the indentation measuring system and the tower and is carried on the main board together.
9. A standard microhardness tester according to claim 2 or claim 3, wherein: the automatic focusing system, the test force loading system, the indentation measuring system and the tower conversion system are jointly carried on the machine body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811525568.XA CN109342179B (en) | 2018-12-13 | 2018-12-13 | Standard microhardness tester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811525568.XA CN109342179B (en) | 2018-12-13 | 2018-12-13 | Standard microhardness tester |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109342179A CN109342179A (en) | 2019-02-15 |
| CN109342179B true CN109342179B (en) | 2021-04-06 |
Family
ID=65304546
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811525568.XA Active CN109342179B (en) | 2018-12-13 | 2018-12-13 | Standard microhardness tester |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109342179B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110047343B (en) * | 2019-03-27 | 2021-07-20 | 北京市理化分析测试中心 | Method for operating VR (virtual reality) simulation microhardness meter |
| CN110082231B (en) * | 2019-05-27 | 2024-04-26 | 平湖莱顿光学仪器制造有限公司 | Multi-connecting rod loading device and microscope |
| CN110864987B (en) * | 2019-11-29 | 2022-03-29 | 中国航空工业集团公司北京长城计量测试技术研究所 | Two-section type electromagnetic force application system of high-precision microhardness tester |
| CN112014205A (en) * | 2020-10-09 | 2020-12-01 | 中国航空工业集团公司北京长城计量测试技术研究所 | Microhardness meter with multi-sample automatic calibration function |
| CN112098191A (en) * | 2020-10-09 | 2020-12-18 | 中国航空工业集团公司北京长城计量测试技术研究所 | Special fixture for multi-sample microhardness block test |
| CN113720264B (en) * | 2021-07-19 | 2024-04-26 | 湘潭大学 | Focusing measurement method and device for camera of sclerometer |
| CN114383963A (en) * | 2021-12-15 | 2022-04-22 | 迈格仪器(苏州)有限公司 | Indentation reading method of micro Vickers hardness tester |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4611487A (en) * | 1984-03-16 | 1986-09-16 | Anton Paar, Kg | Micro hardness testing device |
| CN1310334A (en) * | 2001-04-05 | 2001-08-29 | 上海恒一电子测试设备有限公司 | Guide rail type loader for microscopic hardness meter |
| CN101526452A (en) * | 2009-04-16 | 2009-09-09 | 莱州华银试验仪器有限公司 | Automatic turret type electronic mainshaft measuring unit of Brinell hardness tester |
| CN201322709Y (en) * | 2008-12-22 | 2009-10-07 | 沈阳天星试验仪器有限公司 | Portable hardness tester |
| CN103353431A (en) * | 2013-07-12 | 2013-10-16 | 吉林大学 | In-situ indentation mechanical testing device based on tensile compression and fatigue combined load mode |
| CN203519441U (en) * | 2013-10-21 | 2014-04-02 | 上海研润光机科技有限公司 | Intelligent metallographic analysis and hardness measurement system |
| CN204064831U (en) * | 2014-08-29 | 2014-12-31 | 上海奥龙星迪检测设备有限公司 | Accurate microhardness testers |
| CN205067206U (en) * | 2015-08-04 | 2016-03-02 | 上海尚材试验机有限公司 | Vickers |
| CN205067207U (en) * | 2015-08-04 | 2016-03-02 | 上海尚材试验机有限公司 | Brinell hardness tester |
| CN107045176A (en) * | 2017-02-22 | 2017-08-15 | 上海钜晶精密仪器制造有限公司 | Microhardness testers automatic lifting focusing mechanism |
-
2018
- 2018-12-13 CN CN201811525568.XA patent/CN109342179B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4611487A (en) * | 1984-03-16 | 1986-09-16 | Anton Paar, Kg | Micro hardness testing device |
| CN1310334A (en) * | 2001-04-05 | 2001-08-29 | 上海恒一电子测试设备有限公司 | Guide rail type loader for microscopic hardness meter |
| CN201322709Y (en) * | 2008-12-22 | 2009-10-07 | 沈阳天星试验仪器有限公司 | Portable hardness tester |
| CN101526452A (en) * | 2009-04-16 | 2009-09-09 | 莱州华银试验仪器有限公司 | Automatic turret type electronic mainshaft measuring unit of Brinell hardness tester |
| CN103353431A (en) * | 2013-07-12 | 2013-10-16 | 吉林大学 | In-situ indentation mechanical testing device based on tensile compression and fatigue combined load mode |
| CN203519441U (en) * | 2013-10-21 | 2014-04-02 | 上海研润光机科技有限公司 | Intelligent metallographic analysis and hardness measurement system |
| CN204064831U (en) * | 2014-08-29 | 2014-12-31 | 上海奥龙星迪检测设备有限公司 | Accurate microhardness testers |
| CN205067206U (en) * | 2015-08-04 | 2016-03-02 | 上海尚材试验机有限公司 | Vickers |
| CN205067207U (en) * | 2015-08-04 | 2016-03-02 | 上海尚材试验机有限公司 | Brinell hardness tester |
| CN107045176A (en) * | 2017-02-22 | 2017-08-15 | 上海钜晶精密仪器制造有限公司 | Microhardness testers automatic lifting focusing mechanism |
Non-Patent Citations (1)
| Title |
|---|
| 智能加载激光洛氏硬度标准装置;石伟 等;《计测技术》;20150411;第41-49页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109342179A (en) | 2019-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109342179B (en) | Standard microhardness tester | |
| EP2135030B1 (en) | Method and device for optically measuring external threads | |
| CN101387761B (en) | Center aligning assembling and regulating apparatus and method for optical system | |
| CN101261234B (en) | Surface flaw detection device | |
| CN106814546B (en) | Focal plane detection device, focal plane scaling method and silicon wafer exposure method | |
| US20190025048A1 (en) | Three-dimensional measuring device | |
| CN108254853B (en) | Microscopic imaging system and real-time focusing method thereof | |
| CN104317041A (en) | Self-focusing light path system | |
| CN114113114A (en) | Automatic process method for detecting and repairing micro-defects on surface of large-diameter element | |
| DE3339970A1 (en) | DEVICE FOR AUTOMATIC FOCUSING OF OPTICAL DEVICES | |
| CN208421371U (en) | Improve the device of high definition zoom lens dress school efficiency and image quality | |
| US7636466B2 (en) | System and method for inspecting workpieces having microscopic features | |
| CN114113115A (en) | High-precision automatic positioning method for micro-defects on surface of large-diameter element | |
| CN114858817A (en) | Detection device and method for protective lens of galvanometer | |
| CN110006921B (en) | Automatic pose adjusting method and device for large-curvature-radius spherical optical element | |
| CN117092113A (en) | Camera mould welding quality detection device and system thereof | |
| CN115825078A (en) | Resin lens defect detection device and method | |
| CN106896109A (en) | Systems for optical inspection and its detection method | |
| CN114111578B (en) | Automatic pose determining method for large-caliber element | |
| JP2001013388A (en) | Optical axis adjustment method for lens system and optical axis adjustment device for lens system | |
| DE10244767A1 (en) | Method and device for determining the distance between a reference plane and an inner or outer optical interface of an object, and use thereof for determining a surface profile of an, in particular metallic, object, autofocus module, microscope and method for autofocusing a microscope | |
| TWI685639B (en) | Shape measuring device and coating device equipped with the device | |
| CN115278072A (en) | Automatic focusing method and system for Micro LED detection | |
| DE3916385C2 (en) | Method and arrangement for geometric height measurement | |
| CN109471253B (en) | Automatic focusing system of microhardometer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |