JP2000146793A - Hardness testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hardness testing machine by which a hollow can be formed in a proper size. SOLUTION: In this hardness testing machine, a hollow formed by applying a prescribed testing force to the surface of a sample through an indenter is observed via an optical system including an optical microscope having two objective lenses, and the hardness of the sample is found on the basis of its size. In the hardness testing machine, an up-key and a down-key, at an operator panel 50, which input a hardness estimated value are provided. In addition, a ROM 23 in which testing-force data as data on a testing force and data on a hollow decided for every objective lens as data on the size of a hollow in a range suitable for observing the performance of the optical system are stored is provided. In addition, a CPU 21 in which the size of a hollow capable of being formed actually on the sample is computed on the basis of the estimated value and the testing force, in which the size of the hollow obtained by this computation is compared with the hollow data and which sets a proper testing force and proper objective lenses is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for observing a recess formed by applying a predetermined test force to a sample surface by an indenter through an optical system including an optical microscope, and determining the size of the sample from the size thereof. The present invention relates to a hardness tester for determining hardness.

[0002]

2. Description of the Related Art A hardness tester for measuring the hardness of a sample based on the size of a depression formed by applying a test force by an indenter is provided with an optical microscope for observing the depression. The measurement range of this optical microscope is mainly limited by the magnification of the objective lens. For example, when observation is performed with a 10 × objective lens, the maximum length of the observable range is about 500 μm. Further, in the case of a type with a TV monitor, which has been increasing in recent years, the measurement is performed within a range of about 200 μm even with a 10 × objective lens. When measuring hardness with the hardness tester, the tester sets the sample on the stage, determines the test force arbitrarily, performs indentation with an indenter, observes the formed indentations, and measures the size. However, in general, if the size of the depression is about one-half to two-thirds of the measurable range as described above, measurement is easy and an error hardly occurs.

[0003]

However, if the test force is too large compared to the hardness of the sample, a depression larger than the measurement range of the optical system may be formed.
In such a case, it is necessary to change the test force and perform the hollow again, which requires time and labor. Conversely, if the test force is too small with respect to the hardness of the sample to be tested, the pits formed will be small, making accurate observation and measurement difficult, and possibly causing errors.

In view of the above problems, the present invention is capable of forming a recess of an appropriate size within a measurement range limited by the performance of an optical system provided in a hardness tester, It is an object of the present invention to provide a hardness tester that can measure quickly and accurately.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention according to the first aspect is directed to an optical microscope in which a depression formed by applying a predetermined test force to a sample surface by an indenter is used. Observed through the optical system including
In a hardness tester for obtaining the hardness of the sample from the size of the recess, an expected value input means for inputting an expected value of the hardness of the sample, and based on the expected value input by the expected value input means. Setting means for setting the test force such that a recess having a size suitable for observation in terms of performance of the optical system is formed; and Test force control means for controlling the test force so as to press the sample.

The tester can predict the hardness of the sample to be measured, unless the material is very unknown, and the present invention utilizes this point.
That is, according to the first aspect of the present invention, the value of the hardness of the sample expected by the tester is input by the expected value input means. In response to this, the test force is set by the setting means so that a recess having a size in a range suitable for observation in terms of the performance of the optical system is formed, and during the test, the test force is set by the test force control means. The test force is controlled such that the indenter presses the sample with the test force. Therefore, when a test is performed with this hardness tester, a depression having a size suitable for observation due to the performance of the optical system is formed, and a depression that is too large beyond the measurement range of the optical system is formed. And the measurement error becomes large because a dent that is too small is formed, so that measurement can be performed quickly and accurately.

Here, the "range suitable for observation in terms of the performance of the optical system" is, for example, about 1/2 to 2/2 of the measurable range determined by the magnification of the objective lens. However, the size is not limited to this, and is determined to be appropriate in view of the performance of the optical system related to the observation of the sample in the hardness tester comprehensively. The expected value input means is provided on an operation panel or the like, and includes, for example, an up / down key capable of continuously changing a number by operating, and a numeric keypad capable of directly inputting a number. .

According to a second aspect of the present invention, there is provided an optical microscope having a plurality of objective lenses, wherein a depression formed by applying a predetermined test force which can be set within a certain range to a sample surface by an indenter is provided. In a hardness tester for observing through an optical system including, and obtaining the hardness of the sample from the size of the depression, an expected value input means for inputting an expected value of the hardness of the sample, and a configurable test A memory for storing test force data as force value data and dent data defined for each of the plurality of objective lenses as dent size data in a range suitable for observation in terms of performance of the optical system. Means, and a size of a recess that can be formed in the sample for each value of the test force based on the expected value input by the expected value input means and the test force data stored in the storage means. Is calculated, and the size of the depression obtained by the calculation is compared with the depression data, and based on the comparison result, setting means for setting an appropriate test force and an objective lens, and setting by the setting means With the set test force, the objective lens is driven so that the indenter presses the sample so that the observation is performed using a test force control unit that controls a test force and an objective lens set by the setting unit. And an objective lens driving means.

According to the second aspect of the present invention, the value of the hardness of the sample expected by the tester is input by the expected value input means. In response to this, the setting means calculates the size of the pit that can be actually formed in the sample from the test force data and the expected value for each value that can be applied as the test force, and then calculates the size by this calculation. The size of the dent and the data of the size of the dent in a range suitable for observation on the performance of the optical system, and the dent data determined for each of the plurality of objective lenses are compared, and based on the comparison result, The appropriate test force and objective lens are set. During the test, the test force is controlled such that the indenter presses the sample with the test force set by the test force control means, and a recess having a size suitable for observation in terms of the performance of the optical system is formed. The objective lens set by the setting means
It is driven by the objective lens driving means, and can be observed using this objective lens. Therefore, when a test is performed with this hardness tester, a depression having a size appropriate for the performance of the optical system is formed in consideration of the magnification of the objective lens, so that the size exceeds the measurement range of the optical system. It is less likely that a too large depression is formed and redoing is performed again, and that a too small depression is formed and a measurement error becomes large, so that measurement can be performed quickly and accurately.

Here, the expected value input means or "the size of the range suitable for observation in terms of the performance of the optical system" is the same as in claim 1.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a Vickers tester as an example of the hardness tester of the present invention. The Vickers testing machine 1 performs a test in which the surface of a sample is pressed with a predetermined test force by a square pyramid diamond indenter, and the hardness of the sample is determined from the size of the formed depression (indentation). , A main body 10, a TV monitor 30, and an operation panel 50. The TV monitor 30 is connected to the TV camera 12 by a cable 31, and the operation panel 50 is connected to the main body 1 by a cable 51.

The main body 10 includes a sample stage 11, a TV camera 12, a halogen lamp 13, and the like. The sample stage 11, on which a sample is placed, can be adjusted in XY directions in a horizontal plane. The halogen lamp 1
Reference numeral 3 denotes a light source for irradiating the sample with light when observing the hollow.
6 (see FIG. 2), the light amount is adjusted.

Further, a quadrangular pyramid diamond indenter (not shown) is provided at a position facing the sample stage 11. This diamond indenter is configured to be movable in the up-down direction, and is positioned at an opposing position under the control of the test force control mechanism 27 with the test force set by the CPU 21 or the test force set by the tester with the test force setting knob 14. Is placed,
The depression is formed by pressing the sample surface. The test force that can be applied to the sample is within a certain range, for example, from 9.807 N to 490.3 N (1 kgf
５０50 kgf), or 1.96 kgf).
The range is 1N to 196.1N (0.2 kgf to 20 kgf).

Further, the main body 10 incorporates an optical microscope (not shown) for observing the sample placed on the sample stage 11. This optical microscope is a digital type microscope equipped with a 10 × eyepiece and two 10 × and 20 × objective lenses. The two objective lenses are automatically switched by an objective lens driving mechanism 25 described later. The image of the sample surface enlarged by the optical microscope is photographed by the TV camera 12 and displayed on the TV monitor 30 via the cable 51.

The operation panel 50 is used by the tester to issue a command at the time of measurement and displays various information during the test.
The touch panel type has a CD (liquid crystal display) screen and is operated by various switches displayed on the screen.

As shown in FIG. 3, the operation panel 50 is provided with an up key 51 and a down key 52, and the tester operates the two keys in advance to operate the two keys.
An expected value (expected value) of the hardness of the sample can be input, and the value is displayed on the hardness value display section 53 in a state as shown in FIG. 3, for example. I have.
The up key 51 and the down key 52 serve as expected value input means of the present invention. When the tester touches the start switch 54, the test starts, and when the test is completed and the hardness value is calculated, the hardness value display unit 53 displays a value different from the expected value on the hardness value display unit 53, for example, as shown in FIG. It is displayed in the state as shown. In addition, the operation panel 50 is provided with a depression value display section 55 for displaying the size of the depression, a test force display section 56, a test force holding time display section 57, and the like.

The main body 10 has a built-in control system 20 for controlling the operation of the Vickers tester 1 as shown in FIG. The control system 20 includes a CPU (central process).
sing unit) 21, I / O port 22, ROM (read on)
ly memory) 23, RAM (ramdom access memory) 2
4 and so on. The CPU 21 executes RA processing according to programs and data stored in the ROM 23.
The driver of each section of the tester 1 is controlled via the I / O port 22 while using the M24 as a memory area. The ROM 23 (storage means) stores test force data that is data of a value that can be taken as a test force within the above-described predetermined range. Further, depression data, which is data of the size of the depression in a range suitable for observation in view of the performance of the entire optical system including the optical microscope, is also stored for each of the two objective lenses.

When an expected value of hardness is input from the operation panel 50 by the up key 51 and the down key 52, the CPU 21 sets an appropriate test force and an objective lens according to the hardness, that is, , CPU 21 are setting means of the present invention.

The procedure for setting the test force and the objective lens will be described below. Up key 51 or Down key 5
When the expected value of the hardness of the sample is input by the
From the predicted value and the test force data stored in the ROM 23, the size of the pit that can be formed in the sample is calculated for each test force value that can be taken as the test force. The size of the depression for each test force obtained by this calculation is
The test force at the time when the size of the recess overlapping with the recess data is compared with the above-described recess data for each objective lens is set as the test force in the measurement. Also, the objective lens having the overlapping depression data is set as an observation objective lens. For example, if the size of the depression at a certain test force (a (N)) calculated by the CPU 21 and the value of the depression data in the 10 × objective lens overlap, a (N) is used as the test force. Is set, and a 10 × objective lens is set.

Depending on the hardness of the sample, the indentation data and
In the case where the ranges of the sizes of the depressions obtained by the calculation of the CPU 21 considerably overlap, that is, there are a plurality of test forces that can be set, or there are cases where both objective lenses can be set, Rules are appropriately set so that the test force and the objective lens are finally set as appropriate. For example, if multiple test forces can be selected, select a large test force so that a larger depression is formed. If either objective lens is acceptable, give priority to a 10x lens. Etc.

During the test, the diamond indenter is controlled by the test force control mechanism (test force control means) 27 under the control of the CPU 21 so as to press the sample with the test force set as described above. Thereafter, the objective lens driving mechanism (objective lens driving means) 25 is driven so that the objective lens set as described above comes to a position facing the sample.

The dent observation unit 28 is composed of an eyepiece of an optical microscope and the like, observes the dent of the sample surface under the control of the CPU 21, further measures the size of the dent, and obtains an image of the obtained sample surface. The measured data is sent to CPU 2
1 is output. The CPU 21 outputs the transmitted image to the TV monitor 30 via the TV camera 12 (FIG. 1), calculates the hardness from the measured data, and displays the hardness on the hardness value display unit 53 of the operation panel 50. It is displayed.

The main body 10 has a test force switching knob 14.
The tester can set the test force by himself when an appropriate test force can be predicted in advance or when a test such as JIS is performed. .

Next, the procedure of a hardness test using the Vickers testing machine 1 having the above configuration will be described. First, the tester operates the up key 51 and the down key 5 on the operation panel 50.
2 is operated to input the expected value of the hardness of the sample to be tested. As shown in FIG.
3 is displayed. As described above, the CPU 21 sets an appropriate test force and an objective lens suitable for observation based on the input predicted value, as described above.

When the tester places a sample on the sample stage 11 and presses the start switch 54 of the operation panel 50,
Under the control of the test force control mechanism 27, the diamond indenter advances downward, presses the sample surface with the set test force, and after a predetermined time elapses, the indenter rises and separates from the sample surface. As a result, indentations (dents) are formed on the sample surface by the quadrangular pyramid of the indenter. Next, the objective lens driving mechanism 2
By the control of 5, the previously set objective lens is located above the sample. The state of the sample surface is observed through this objective lens, and the image is
The image is displayed on the V monitor 30. Also, the hollow observation unit 28
The size of the dent is automatically measured, and the value of the hardness is calculated from the size and the value of the applied test force by the existing calculation formula. The actual hardness value is shown in FIG. As shown, it is displayed on the hardness display section 53 of the operation panel 50.

According to the Vickers tester 1 described above, the CP
By U21, the size of the pit that can actually be formed in the sample from the test force data and the expected value is obtained by calculation for each test force that can be added as the test force, and the size of the pit obtained by this calculation and the optical system Data of the size of the dents in a range suitable for observation in terms of the performance of
The depression data determined for each of the objective lenses is compared with each other, and the test force and the objective lens when they overlap are set as the test force in the measurement and the objective lens used for observation. During the test, the indenter presses the sample with the set test force to form a recess having a size suitable for observation due to the performance of the optical system. At the time of observation, observation is performed using the set objective lens.

Therefore, when a test is carried out with this hardness tester, a depression having a size suitable for observation is formed due to the performance of the optical system in consideration of the magnification of the objective lens. In this case, it is difficult to cause a situation in which a dent that is too large is formed and the dent formation is redone, or a dent that is too small is formed to increase the measurement error. Therefore, measurement can be performed quickly and accurately.

In the hardness tester of the present invention, the type and the number of the attached objective lenses are not limited. In this case, the recess data is stored in the ROM 23 for each of the attached objective lenses. Become. Further, the number of objective lenses may be one, and in that case, there is only one kind of depression data, and it may be configured such that an appropriate test force is set when an expected value is input.

Further, the Vickers tester 1 of the type for observing the depression with a TV monitor has been exemplified.
The present invention is not limited to this. For example, as shown in FIG.
A Vickers tester 100 of a type to which an operation panel 103 similar to the operation panel 50 is connected and in which the depression is directly observed by an eyepiece provided in the main body 101.
It may be.

[0030]

According to the first aspect of the present invention, the value of the hardness of the sample expected by the tester is input by the expected value input means. In response to this, the test force is set by the setting means so that a recess having a size in a range suitable for observation in terms of the performance of the optical system is formed, and during the test, the test force is set by the test force control means. The test force is controlled such that the indenter presses the sample with the test force. Therefore, when a test is performed with this hardness tester, a depression having a size suitable for observation due to the performance of the optical system is formed, and a depression that is too large beyond the measurement range of the optical system is formed. And the measurement error becomes large because a dent that is too small is formed, so that measurement can be performed quickly and accurately.

According to the second aspect of the present invention, the value of the hardness of the sample expected by the tester is input by the expected value input means. In response to this, the setting means calculates the size of the pit that can be actually formed in the sample from the test force data and the expected value for each value that can be applied as the test force, and then calculates the size by this calculation. The size of the dent and the data of the size of the dent in a range suitable for observation on the performance of the optical system, and the dent data determined for each of the plurality of objective lenses are compared, and based on the comparison result, The appropriate test force and objective lens are set. Therefore, when a test is performed with this hardness tester, a depression having a size suitable for observation due to the performance of the optical system is formed, and a depression that is too large beyond the measurement range of the optical system is formed. And the measurement error becomes large because a dent that is too small is formed, so that measurement can be performed quickly and accurately.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a hardness tester of the present invention.

FIG. 2 is a block diagram showing a configuration of a control system of the hardness tester of FIG.

FIG. 3 is a plan view showing a state where an expected value of hardness is input to the operation panel of FIG. 1;

FIG. 4 is a plan view showing a state where actual values of hardness are displayed on the operation panel of FIG. 1;

FIG. 5 is a perspective view showing another example of the hardness tester of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 100 Hardness tester 10, 101 Main body 20 Control system 21 CPU (setting means) 23 RAM 24 ROM (storage means) 25 Objective lens drive mechanism (objective lens drive means) 27 Test force control mechanism (test force control means) Reference Signs List 30 TV monitor 50, 103 Operation panel 51 Up key (expected value input means) 52 Down key (expected value input means) 53 Hardness value display unit 54 Start switch 55 Indentation value display unit

Claims (2)

[Claims] 1. A depression formed by applying a predetermined test force to a sample surface by an indenter is observed through an optical system including an optical microscope, and the hardness of the sample is determined from the size of the depression. In the hardness tester to be determined, an expected value input means for inputting an expected value of hardness of the sample, and based on the expected value input by the expected value input means, suitable for observation in terms of performance of the optical system. Setting means for setting the test force so that a depression having a size of a range is formed; and a test for controlling the test force so that the indenter presses the sample with the test force set by the setting means. A hardness tester comprising: a force control unit. 2. A depression formed by applying a predetermined test force, which can be set within a certain range, to a sample surface by an indenter, is formed through an optical system including an optical microscope having a plurality of objective lenses. In a hardness tester for observing and obtaining the hardness of the sample from the size of the depression, an expected value input means for inputting an expected value of the hardness of the sample, and data of a settable test force value. Test force data,
Storage means for storing, as the data of the size of the depression in a range suitable for observation in terms of the performance of the optical system, depression data determined for each of the plurality of objective lenses, and input by the expected value input means Based on the expected value and the test force data stored in the storage means, calculate the size of the recess that can be formed in the sample for each value of the test force, and calculate the size of the recess obtained by the calculation. Setting means for setting an appropriate test force and an objective lens based on the comparison result with the indentation data, and the test force set by the setting means, so that the indenter presses the sample, Test force control means for controlling a test force; and objective lens driving means for driving the objective lens so that the observation is performed using the objective lens set by the setting means. Hardness tester, characterized in that.