JPH073386B2 - Ultra-small material testing equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ultrafine material testing apparatus used for testing the strength and the like of a thin film formed on the surface of a test object.

[Prior Art] In the ultra-small material testing device, the depth of the indentation is measured based on the output of the displacement detector when the indenter contacts the sample surface, and when the indenter contacts the sample surface. It is important to detect accurately. Therefore, by detecting the change rate of the displacement amount of the indenter with respect to the displacement detection of the indenter, a time point at which the change rate is large is grasped, and this time point is detected as a contact point.

[Problems to be Solved by the Invention] In order to detect the contact point described above, it is necessary to determine a displacement change point based on data of several points, and the accuracy increases as the number of data to be determined increases. improves. However, if the number of data for determination is increased, the time required for the determination processing will increase and the error included in the measurement data will increase. Moreover, since the change point of the displacement change rate is determined in real time, there is a problem that it is easily affected by a disturbance such as vibration or air vibration.

[Means for Solving the Problems] The present invention adopts the following configurations in order to solve the above problems.

That is, the ultra-fine material test apparatus according to the present invention is an ultra-fine material test apparatus that determines the characteristics of a material by pushing it into the sample surface of an indenter, and is a load that electrically generates a test load applied to the indenter. The generation means, the displacement detection means for detecting the displacement amount of the indenter, the change point determination means for reading the displacement output from the displacement detection means and determining the change point of the displacement output, and the change point determination means after the start of the test. Until it is determined that the indenter has come into contact with the sample surface, the initial data storage means including a ring memory that temporarily stores the load / displacement data from the load generation means and the displacement detection means, and the indenter actually Including the load / displacement data stored in the initial data storage means during the time required for the determination of the contact time after the contact with the sample surface, the sample surface contact determination is completed. Characterized by comprising a test data storage means for storing the load-displacement data during the test.

[Operation] After the start of the test, the load / displacement data is stored in the initial data storage means until the change point determination means completes the determination that the indenter is in contact with the sample surface. After the contact point determination, the actual test data including the load / displacement data stored in the initial data storage unit is stored in another test data storage unit during the determination process. Therefore, it is possible to supplement the data that could not be collected in the test data storage means while judging the change point of the displacement change rate in real time, and it is possible to measure the displacement change point for a long time, and the measurement error due to disturbance Can be prevented.

[Embodiment] FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention, in which an indenter 2 is pushed into a sample 1 by an electromagnetic force generating means 4 which constitutes a load means, and a displacement amount of the indenter 2 is measured by a differential transformer method. The displacement detector 3 detects the displacement. That is, CPU1
A load signal is output from 5 and a load current is supplied to the electromagnetic force generating means 4 via the D / A converter 6 and the current amplifier 5, and the indenter 2 is pushed into the sample 1 by the driving force of the electromagnetic force generating means 4.
The load current supplied by the electromagnetic force generating means 4 and the displacement signal from the displacement detector 3 are read out as voltage values, converted into frequency signals by the V / F converters 8 and 9, respectively, and are counted.
It is counted in 10,11 and input to CPU15 as load / displacement data. The load / displacement data input to the CPU15 is stored in the memory unit 1
CRT1 is stored in 6 and processed through I / O17
It is output to 8 and the relationship between the load and the indentation depth is recorded.

The CPU 15 obtains the displacement change rate of the indenter 2 based on the displacement signal from the displacement detector 3 and determines the change point of the displacement output as the contact point between the indenter 2 and the surface of the sample 1.

After the start of the test, the load / displacement data is stored in the memory until the indenter 2 descends in the air and contacts the surface of the sample 1.
It is stored in 16 initial data storage means or A memory. The A memory is a so-called ring memory, and when the storage capacity of the data is written and becomes full, the input data returns to the beginning and is overwritten, and the stored contents are sequentially updated. The memory unit 16 further includes a B memory which is a test data storage means. The B memory stores the load / displacement data of the actual test after the contact time between the indenter and the sample surface is determined. The data written in the memory A during the time required for the determination of is also stored as the actual data.

Figure 2 shows the load / displacement characteristics displayed on the CRT18.
The procedure of the storage process will be described with reference to this figure. During the time T ₁ from the start of the test until the contact point is determined, the data is stored in the A memory, which is a ring memory, and after the determination, the indenter actually contacts the sample. Then, the data of the actual test including the data during the time T ₂ required for the determination of the contact point is stored in the B memory.

FIG. 3 is a diagram conceptually showing the structure of the memory section 16.

By configuring the memory unit and performing the storage process in this way, it is possible to prevent data loss during the process of determining the contact point after the indenter actually contacts the sample surface. Therefore, since the change point can be determined in real time with a larger number of data and the displacement change rate can be measured for a long time, a measurement error is less likely to occur due to the influence of disturbance. Therefore, it is possible to reduce the number of test mistakes and prevent a situation where the measurement time becomes long due to the retest.

Further, since it is less likely to be affected by disturbance, restrictions on the environment where the apparatus is installed are loosened.

[Effects of the Invention] As is clear from the above description, according to the ultrafine material testing apparatus of the present invention, it is possible to prevent data loss in the time required for the contact determination process between the indenter and the sample surface. , It has become possible to significantly reduce judgment errors due to the effects of disturbance.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG.
FIG. 3 is a diagram showing load / displacement characteristics, and FIG. 3 is a diagram conceptually showing the configuration of the memory section. 1 ... Sample, 2 ... indenter 3 ... displacement detector, 15 ... CPU 16 ... memory section

Claims (1)

[Claims] 1. An ultra-small material testing apparatus for determining the characteristics of a material by pushing it into the sample surface of an indenter, comprising load generating means for electrically generating a test load applied to the indenter,
Displacement detection means for detecting the displacement amount of the indenter, change point determination means for reading the displacement output from this displacement detection means and determining the change point of the displacement output, and indenter after the start of the test by the change point determination means Until it is determined that the load has come into contact with the sample, the initial data storage means including a ring memory that temporarily stores the load / displacement data from the load generation means and the displacement detection means, and the indenter actually contacts the sample surface. Then, including the load / displacement data stored in the initial data storage means during the time required for the determination of the contact time, the load during the test after the completion of the sample surface contact determination
An ultrafine material testing apparatus comprising a test data storage unit for storing displacement data.