JPS63222234A - Strain/stress measuring film - Google Patents

Abstract

PURPOSE:To measure strain/stress under temp. and humidity covering a wide range, by forming a ceramic membrane to the surface of an object to be measured using a vacuum vapor deposition method and measuring the cracks generated in said membrane. CONSTITUTION:A ceramic membrane (TiN, TiC or the like) is coated to an object 1 to be measured by an apparatus 7 such as an ion plating apparatus. When external force acts on the object 1 to be measured having the ceramic membrane coated to the surface thereof and strain is generated, a large number of cracks are generated in the ceramic membrane. By counting the intervals between the cracks or the number of said cracks per unit length, the quantity of the strain in the object 1 to be measured is evaluated.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a strain/stress measurement membrane.

[Conventional technology]

Distortion that occurs in the measured object due to cracks in the film.

A coating called a "stress coating" is known as a device for measuring stress.

This type of stressed coating film is very brittle, so the interval between cracks or the number of cracks per unit length depends on the amount of strain applied to the object to be measured, so by counting this number, If the strain occurring in the object to be measured can be known, and the stress-strain characteristics of the object to be measured are known,
It is possible to know the stress generated in the object to be measured.

[Problem that the invention seeks to solve]

However, this paint film can only be used in the temperature range of 0°C to 100°C;
It has the disadvantage that it cannot be applied to components such as boilers and turbines.

The present fl Bg was proposed in view of these circumstances, and its purpose is to provide a strain/stress measurement membrane that can be used over a wide range of temperature and humidity.

[Means for solving problems]

To this end, this product is characterized by being made of a ceramic thin film that is formed on the surface of the object to be measured by vacuum evaporation, and allows stress and strain to be determined by measuring cracks that occur due to strain.

[For production]

With such a configuration, the ceramic thin film is extremely brittle (similar to "stress coatings", when a strain occurs on the object to be measured, cracks corresponding to the amount of strain will occur perpendicular to the direction of the strain). .

〔Example〕

To explain one embodiment of the present invention with reference to the drawings, the first figure is a plan view showing the procedure for coating an object to be measured with a ceramic thin film, and the second figure is a plan view showing the method of coating an object to be measured with a ceramic thin film in the manner shown in Fig. 1. FIG. 3 is a partially enlarged view of section III in FIG. 2, and FIG. 4 is a diagram showing the relationship between the number of cracks and strain in FIG. 3.

First, as shown in FIG. 1, a ceramic thin film (TjN, Tic, etc.) is coated on the object to be measured 1 using an ion blating device 7 or the like.

As shown in FIG. 2, when an external force is applied to the object to be measured 1 whose surface is coated with the ceramic thin film 2 and a strain is generated, the surface properties of the ceramic thin film 2 change.

When this is observed with a magnifying glass at a magnification of several tens to 100 times, a large number of cracks 3 can be seen perpendicular to the strain direction, as shown in FIG.

The interval between these cracks or the number of cracks per unit length has a correlation with the strain that occurs in the object to be measured 1, as shown in Figure 4, so the interval between these cracks or the number of cracks per unit length is counted. By this, the amount of strain occurring in the object to be measured 1 can be estimated.

Furthermore, since cracks occur in the direction J perpendicular to the direction of strain, the direction of strain occurring in the object to be measured 1 can also be estimated.

[Effects of Mamachi]

Ceramic thin films are not easily affected by temperature and humidity, so stress and strain can be measured even in high-temperature environments up to several hundred degrees Celsius and/or high-humidity environments up to 100%.

In short, according to the present invention, strain is formed on the surface of the object to be measured by vacuum evaporation. By using a ceramic thin film that can determine stress and strain by measuring the cracks that occur, a strain/stress measurement film that can be used over a wide range of temperature and humidity is obtained, and therefore the present invention has industrial applications. Above all, it is extremely useful.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the method of ceramic coating according to an embodiment of the present invention, FIG. FIG. 3 is a partially enlarged view showing the part ■ in FIG. 2, and FIG. 4 is a diagram showing the relationship between the number of cracks and strain in FIG. FIG. 5 is a plan view showing the occurrence of cracks in a conventional stress coating film. 1. Object to be measured, 2. Ceramic thin film, 3. Crack, 4. Amount of strain that occurred in the object to be measured, 5. Number of cracks per unit length or crack interval that occurred in the ceramic thin film. Reciprocal number, 6... Stress coating film, 7... Coating equipment agent for ion blating, etc. Patent attorney Masafumi Tsukamoto Part 1vA Figure 2 Figure 3 Figure 4 Figure 5 Procedural amendment document August 1986 3rd 1 Display of the case Patent Application No. 56010 of 1988 2 Name of the invention Strain/Stress Measuring Membrane 3 Person making the amendment Relationship to the case Applicant Postal code 100 Address No. 1 S, Marunouchi 2-chome, Chiyoda-ku, Tokyo Name (620) Mitsubishi Heavy Industries, Ltd. 4 Agent postal code 160 Address No. 3-5, 5-5 Minamimotomachi, Shinjuku-ku, Tokyo Date of amendment order May 26, 1988 7 Contents of amendment

Claims (1)

[Claims] Strain/stress measurement characterized by comprising a ceramic thin film formed on the surface of an object to be measured by vacuum evaporation and capable of determining stress/strain by measuring cracks caused by strain. film.