JPS624655B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to an improvement in an adhesion tester for testing the adhesion of surface coatings such as plating, by scratching the surface coating with an indenter. Conventionally, in adhesion testing of surface coatings such as plating, bending test method, steel ball indentation method, polishing test method,
Many test methods have been adopted, including the BNF adhesion film test method and the heating test method. In particular, the surface of a material (hereinafter referred to as a sample) on which a surface coating such as plating has been formed is scratched with a steel rod with a spherical tip or a tool with a blunt tip such as a screwdriver to check whether or not the surface coating has peeled off. Because the observation method is simple,
often put into practice. However, the method of scratching the sample surface with a steel rod with a spherical tip or a tool with a blunt tip has the advantage that the test procedure is simple, does not require skill, and the time required for the test is short. The disadvantage is that the presence or absence of scratching largely depends on the shape of the tip of the tool used for scratching, the strength of scratching, the speed of scratching, etc., and reproducibility is poor, and judgments often differ depending on the measurer. It is also an inherently qualitative measurement;
Only a binary determination of the presence or absence of peeling could be made, and quantitative measurement was not possible. This invention was made to eliminate the above-mentioned drawbacks of the conventional indenter, and uses an indenter whose tip has an acute cross-sectional shape in the direction of travel and whose center line is inclined in the direction of travel. By providing a mechanism to apply an arbitrary load to this indenter and a mechanism to move the sample and indenter relative to each other, scratching is performed with a constant load, making semi-quantitative measurement possible and reducing individual differences among the measurers. The object of the present invention is to provide a scratch-type adhesion tester that can perform the following tests. Hereinafter, the present invention will be described in detail with reference to examples. FIG. 1 is a perspective view showing an embodiment of the present invention. In the figure, 1 is a sample, 2 is a sample stand on which the sample is placed and supported, and this sample stand 2 is attached coaxially with a knob 3. By means of a helical gear (not shown) and a helical bulkhead 5 mounted on the main body 4, it is possible to move the knob 3 in the horizontal direction by rotating it. A balance 7 having a fulcrum 6 is attached to the main body 4, and one arm of the balance 7 has a
Holds a rod-shaped indenter 8 with a processed tip and a weight 9
There is a pedestal 10 that can carry a load, and a balance weight 11 for balancing the pedestal 10 is attached to the other arm. 12 is a holder for holding the indenter 8 on the pedestal 10, and 13 is a set screw for attaching the indenter 8 to this holder. The method of operating the adhesion tester is to fix the sample 1 on the sample stand 2 and bring the tip of the indenter 8 attached to the stand 10 into contact with the surface of the sample 1. After loading the weight 9 on the pedestal 10 and applying an arbitrary load to the indenter 8, the knob 3 is rotated to move the sample stage 2 horizontally, and the surface of the sample 1 is scratched with the tip of the indenter 8. Scratch marks on the surface of the sample 1 are observed with the naked eye or with a stereomicroscope to check for peeling and determine adhesion. The indenter is a rod-shaped body with a machined tip, and the tip has an acute cross-sectional shape in the direction of travel.
Use one whose center line is inclined in the direction of travel. The shape of the tip in the direction perpendicular to the direction of movement is preferably a curve such as an arc or a straight line that makes contact with the sample surface. As long as the center line of the tip is inclined, the indenter as a whole may be installed vertically. 2 to 6 show the shape of the tip of the indenter used in the test, A is a front view, B is a side view, and the arrow indicates the direction of movement. Among these, the indenter 8 of the present invention, as shown in Fig. 2, is a bullet-shaped body with a cutout on the opposite side to the direction of travel, and is mounted vertically so that the center line α of the tip is at an angle θ in the direction of travel. Slanted claw-like ones are suitable. Table 1 shows the results of solder plating (thickness 5 μm) after applying nickel underplating (thickness 2 μm) to the phosphor bronze base material.
The results are the results of observing the presence or absence of peeling under a load of 50 to 2000 g with respect to the samples subjected to the indenter tip shape. The indenter material is tool steel with hardness H _R C63.
Using SK2, a round bar with a diameter of 3 mmφ was cut to obtain the required shape.

[Table] The above results show that the bullet-shaped indenter shown in Figure 3 or the square pyramid-shaped indenter shown in Figure 4 have a sharp tip, so they easily pierce the sample surface, and when the load is low (less than 1 kg), the indenter is thin and sharp. Only scratch marks are left and no peeling is observed, and in the case of high loads (1 kg or more), the pressure tip penetrates the sample too deeply, making it impossible to scratch or scratch smoothly. Further, in the case of a hemispherical indenter tip (FIG. 6), the sample surface is only depressed and no peeling occurs at all. The screwdriver-shaped tool shown in Figure 5 can cause delamination, and delamination can be observed even at relatively low loads, but since the indenter tip is linear, it is difficult to make uniform contact between the indenter tip and the sample surface. It is difficult and requires reproducibility. On the other hand, the claw-shaped type shown in Figure 2 can cause peeling at the lowest load, and even under high loads, the tip will not bite too deeply and become impossible to scratch, and even under a load higher than the minimum peeling load. If present, peeling was always observed. Table 2 shows the results of adhesion tests on phosphor bronze solder-plated materials under varying plating conditions using the device of the present invention equipped with the indenter shown in Figure 2, as well as the results of conventional bending tests and heating tests. This is the result. In the table, AB indicates the type of brightener, and a circle mark indicates that no peeling was observed.

[Table] No. 1 to 10 in conventional bending and heating tests
It was thought that all of the samples exhibited good adhesion with no peeling observed, but from the results in Table 2, according to the adhesion tester of the present invention, some samples peeled and the adhesion was poor. It can be seen that there is a lack of In addition, it is possible to semi-quantitatively determine the difference in adhesion depending on the type of base plating or the difference in adhesion depending on the type of brightener, which was impossible to detect with conventional methods, making the adhesion tester of the present invention useful. is clear. The adhesion tester of the present invention is equipped with a mechanism for changing the inclination angle (θ in FIG. 7) of the center line α of the tip of the indenter 8, as shown in the partial front view of FIG. Easy conditions can be found, and in this case, the driver-shaped indenter shown in FIG. 5 can also be used by adding an inclination angle. In FIG. 7, the same reference numerals indicate the same or corresponding parts as in FIG. 1, but the driver-like indenter 8 shown in FIG. 5 is used. The holder is also divided into two parts,
It is composed of an upper holder 12a fixed to the frame 10, and a lower holder 12b attached to the upper holder with a variable angle screw 14 so as to be able to change the angle. The operation of the testing machine shown in FIG. 7 is basically the same as that shown in FIG. 1, except that the indenter 8 is attached to the lower holder 12b using the set screw 13, and the inclination angle θ of the center line is adjusted using the variable angle screw 14. . In order to bring the tip of the indenter 8 into uniform contact with the sample 1, it is sufficient to loosen the set screw 13 and adjust the installation direction of the indenter 8. This improves reproducibility through uniform contact, and a screwdriver type tool can also be used. Become. The mechanism for applying a load in the adhesion tester of the present invention is not limited to a balance and a weight, but any mechanism that can apply a load, such as a spring or air pressure, can be used. Further, the mechanism for relatively moving the sample and the indenter is not limited to the combination of rack and pinion, but other similar mechanisms can be used. Except for the shape of the indenter tip, the adhesion tester of the present invention has
The structural principle is the same as that of a known scratch hardness tester, and they can be used interchangeably by replacing the indenter. Note that the present invention is applicable not only to plating but also to other surface coating adhesion testers. Since the adhesion tester of the present invention facilitates peeling of the surface film of the sample by scratching, the sensitivity of adhesion measurement is improved and semi-quantitative determination can be performed. In addition, the effects of individual differences among the measurers are reduced, and in order to achieve the above effects, it is possible to perform the work with the same ease as the conventional method of scratching with tools, etc. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the adhesion tester of the present invention;
FIG. 2 is a front view A showing the shape of the indenter tip of the present invention;
and side view B, FIGS. 3 to 6 are front views A and side views B showing the shapes of various indenter tips used in tests for comparison with the indenter of the present invention, and FIG. 7 is another indenter of the present invention. FIG. 3 is a front view showing a mechanism for changing the contact angle between an indenter and a sample in an example. In each figure, the same reference numerals indicate the same or equivalent parts, 1 is the sample, 2 is the sample stage, 3 is the knob, 4 is the main body, 5 is the bulkhead, 6 is the fulcrum, 7 is the balance, 8
1 is an indenter, 9 is a weight, 10 is a stand, 11 is a balance weight, and 14 is a variable angle screw.

Claims (1)

[Claims] 1. An indenter that scratches the surface of a sample with its tip, a mechanism that applies a load to the indenter, a sample stand, and a mechanism that moves the indenter relatively to the sample supported on the sample stand. an adhesion test for determining the adhesion of a surface coating, characterized in that the indenter has an acute cross-sectional shape in the direction of travel at the tip and a center line thereof is inclined in the direction of travel; Machine. 2. The adhesion tester according to claim 1, wherein the indenter is a vertically mounted bullet-shaped body with a cutout on the side opposite to the direction of travel. 3. The adhesion tester according to claim 1, wherein the indenter is a rod-shaped body having a cutout surface in the direction of movement and the opposite side thereof, and is attached so as to be inclined in the direction of movement.