JPH07104245B2 - Indentation hardness test method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an indentation hardness test method in which a test load is applied to an indenter and the hardness of the sample is obtained from the indentation depth of the indenter into the sample surface at that time. .

[Prior Art] In the conventional indentation hardness test method, a preset load is applied to an indenter to indent the sample surface, and the indentation depth at that time is obtained to calculate the sample hardness.

[Problems to be Solved by the Invention] When obtaining the indentation depth of an indenter under a constant load as in the conventional test method, the indentation depth changes depending on the hardness of the sample. For example, as shown in the characteristic diagram of FIG. 2, sample A indentation depth D ₁ at a load P _2, the indentation depth Sample B with the same load P ₂
It shows that it becomes D ₂ . FIGS. 3 (a) and 3 (b) show how the indentation depth differs depending on the sample.
When the film thickness is of the same thickness h of, as shown in FIG. (B) D ₂
Since / h is close to 1, the measurement of the sample B is greatly affected by the substrate E. Especially in the case of thin film samples,
Since the ratio of the indentation depth to the film thickness changes and the influence of the substrate E becomes so large that it cannot be ignored, there is a problem that the hardness comparison of the samples cannot be performed accurately.

Therefore, an object of the present invention is to provide an indentation hardness test method capable of performing accurate evaluation and the like in measuring the hardness of thin film samples or the like and comparing the hardness.

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

That is, the indentation hardness test method according to the present invention is the indentation hardness test method for obtaining the hardness of a sample from the test load applied to the indenter and the indentation depth of the indenter pushed by the test load. The indentation depth from the sample surface is set beforehand, and the indentation depth of the indenter is detected by the indentation depth measuring means, and the load increase speed is decreased from the front by a predetermined amount of the set depth, When the set indentation depth is reached, the test load applied to the indenter is measured, and the hardness of the sample is obtained from the measured test load and the preset indentation depth.

[Operation] The indentation depth is set in advance as a depth that is less affected by the substrate on which the sample is placed, and the indenter indentation depth is detected by the indentation depth measuring means, and the indentation depth is determined by a predetermined distance The hardness is calculated by decreasing the load increase acceleration and measuring the test load when the indenter reaches this set indentation depth, so for example the ratio of the indentation depth to the film thickness of a thin film sample becomes constant, and the hardness of the sample The comparison can be done accurately.

[Example] In the test method according to the present invention, for example, as shown in FIG. 3 (a), the indentation depth D ₁ which is less affected by the substrate E is set as a preset indentation depth, and then the electronic balance or the like is used. The load is applied to the indenter by the load means of, and the load is sequentially increased. The displacement of the indenter from the time when the indenter contacts the sample is detected, and the test load at the time when the displacement reaches the set indentation depth is measured. In this case, if the holding time of the load after reaching the set indentation depth is set, the displacement often increases, so the load at the moment when the indentation depth reaches the set value is measured and taken as the dynamic hardness.

If the measured load is P, the set indentation depth is D, and the coefficient depending on the indenter shape is K, the hardness H is calculated as H = K · P / D ² .

In order to perform more accurate measurement in consideration of the increase in displacement of the indenter after loading, as shown in Fig. ₁ , change the load increasing speed from the point of depth D ₀ before reaching the set indentation depth D _1. Decrease and increase the load so that the indentation depth becomes D ₁ between t ₂ −t ₁ = t ₃ for the time t ₂ for reaching D ₁ and the time t ₁ for reaching D _0. Then, measure the indentation depth and load at the time of t ₃ hours. That is, the test is performed by setting D ₁ and D ₀ / D ₁ and t ₃ .

As described above, in the present invention, a load is applied so that the deformation (indentation depth) applied to the sample becomes equal, and the hardness is compared by the difference in the load, so that the influence of the substrate on which the sample is placed is equalized. The hardness can be accurately compared.

[Effects of the Invention] As is clear from the above description, according to the indentation hardness test method of the present invention, the influence from the base on which the sample is placed is equalized while considering the displacement increase of the indenter after the load is applied. Then, the hardness of the sample can be measured. In particular, even in the case of a thin film sample, the hardness comparison can be accurately performed.

[Brief description of drawings]

FIG. 1 is a diagram for explaining setting elements when a test is performed in consideration of an increase in indenter displacement in the embodiment of the present invention, and FIG.
FIG. 3 and FIGS. 3A and 3B are diagrams for explaining the conventional method. A, B …… Sample, E …… Base D ₁ , D ₂ … Indentation depth, h …… Sample thickness

Claims (1)

[Claims] 1. An indentation depth from a sample surface of an indenter in an indentation hardness test method for obtaining a hardness of a sample from a test load applied to the indenter and an indentation depth of the indenter pushed into the sample surface by the test load. Is set in advance, and the pushing depth of the indenter is detected by the pushing depth measuring means.
Decrease the load increasing speed from a predetermined amount before the set depth, measure the test load applied to the indenter when the indenter reaches the set indentation depth, and measure the measured test load and preset indentation. A method for testing indentation hardness, which comprises determining the hardness of a sample from the depth.