JPH0720050A - Device for evaluating abrasion resistance of aluminum alloy containing silicon - Google Patents

Abstract

PURPOSE:To quickly and nondestructively evaluate the abrasion resistance of an aluminum alloy containing silicon by detecting aluminum alloy areas and silicon areas on a surface to be measured as gray-level signals based on the difference between the light reflectivity of the aluminum alloy and that of silicon. CONSTITUTION:The internal surface of a cylinder block 1 is irradiated with the light from a light source 2 and reflected light from the internal surface is passed through a wavelength selection filter 3 and changed in optical path by a reflecting mirror 4. The reflected light is received by means of a light receiving sensor 8 after passing through a photoreceptor 12 and convex lens 7 and converted into gray-level signals based on the difference between the light reflectivity of an aluminum alloy and that of silicon. Since a turntable 6 turns in the circumferential direction around a center axis 13, the linear light receiving sensor 8 can detect the the gray-level signals from the internal surface of the block 1 over the entire circumference. The detected gray-level signals can be directly observed on a monitor 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for evaluating the wear resistance of silicon-containing aluminum alloys, and more specifically, non-destructive evaluation of the wear resistance of sliding surfaces of silicon-containing aluminum alloys constituting automobile engines and the like. The present invention relates to a wear resistance evaluation apparatus for a silicon-containing aluminum alloy that can be used.

[0002]

2. Description of the Related Art Conventionally, a wear resistance test of a metal material has been performed by a test method using a mechanical means, and the wear resistance of the metal material has been measured to evaluate the wear resistance. Abrasion resistance test methods using mechanical means can be roughly classified into two types. One of them is a method of evaluating wear resistance by performing a test in which an actual product is reproduced or simulated and measuring the amount of wear at that time. The other one is based on a test piece [see, for example, Material Testing Handbook (edited by Japan Society for Testing and Materials), pages 293 to 295], conditions under which a test piece having a predetermined size and shape is prepared and an actual product is used. It is a method of evaluating the abrasion resistance by performing a rubbing test with and then measuring the amount of abrasion of the test piece.

In addition to the above two methods, it is known that the wear resistance depends on the distribution state of primary crystal silicon, especially in the case of a silicon-containing aluminum alloy. An evaluation method has been adopted in which the wear resistance is evaluated by visually observing the distribution state of primary crystal silicon. In this case, it is known that if the primary crystal silicon is uniformly distributed in the aluminum alloy with a constant grain size without segregation, the wear resistance is high, and if segregated, the wear resistance is low. The wear resistance is evaluated by visually observing the distribution state of primary crystal silicon in a predetermined region of the sample. That is, if the primary crystal silicon shows a biased distribution due to segregation, a so-called spot pattern of light and dark appears on the surface to be measured, and the measurer judges the wear resistance of the object from this degree.

[0004]

Of the above two methods, the abrasion resistance test using a product is suitable for evaluating an actual product. However, in this test method, factors of wear such as the structure of the product and the temperature of the sliding surface have a complicated influence at the same time, and it is almost impossible to analyze these factors individually. For this reason, there is a problem that it may be difficult to correctly evaluate the wear resistance of the material itself constituting the product.

On the other hand, the wear resistance test method using the test piece can evaluate the wear resistance of the material itself of the test piece.
In this case, the test piece can be manufactured by a method in which the test piece is manufactured under the same conditions as the product, or by cutting the test piece from the product. However, in the case of a silicon-containing aluminum alloy, the distribution state of silicon varies, so that the wear resistance test results also vary. Further, it takes a lot of labor and time to manufacture the test piece, set the abrasion resistance test conditions, and perform the abrasion resistance test.

Further, since the above two methods are so-called destructive tests, it is impossible to inspect all products by any method. Therefore, the two methods are performed on sampled products. In this case, the wear resistance of the whole product (population) is estimated by the sampled wear resistance test result of the product. This estimation is reliable if it consists of normal metal material, the product has almost uniform wear resistance, and the wear resistance test is highly reproducible, and therefore should be performed normally. It is possible. However, as in the case of a silicon-containing aluminum alloy, wear occurs by a microscopic mechanism, and, for example, locally generated wear causes chained wear in the peripheral area, or there is variation in the population. Considering the case, a more excellent abrasion resistance evaluation method is desired in order to guarantee the abrasion resistance of the product or evaluate it with higher reliability.

On the other hand, the method of visually observing the distribution state of the primary crystal silicon of the specimen is essentially a sensory evaluation method,
There may be differences in results depending on the observer, and there may be cases where proper evaluation cannot be performed, such as when the observer is tired or when the measured surface of the subject is contaminated.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a non-destructive, simple and quick evaluation of the wear resistance of a silicon-containing aluminum alloy. To provide a sex evaluation device.

[0009]

A wear resistance evaluation apparatus for a silicon-containing aluminum alloy of the present invention to achieve the above object is to irradiate a smooth surface to be measured made of a silicon-containing aluminum alloy with light from a light source. Then, based on the distribution information about the silicon and the aluminum alloy of the measured surface obtained by detecting the reflected light reflected by the measured surface with the light receiver, for evaluating the wear resistance of the silicon-containing aluminum alloy An apparatus, based on a difference in light reflectance between an aluminum alloy and silicon, a gray level signal detecting means for detecting an aluminum alloy area and a silicon area of a surface to be measured as a gray level signal, and a detected gray level. The level signal represents the numerical value representing the aluminum alloy area and the silicon area based on a predetermined threshold value. By binarizing means for binarizing the measured value and the surface to be measured one-dimensionally, the width A of the aluminum alloy region along the scanning line and the width A of the aluminum region following the aluminum alloy region The width S and the binarized data are measured, and the measured value A, S
Two-dimensional histogram H (A, S) with S as a parameter
And a wear resistance evaluation value calculation means for calculating a wear resistance evaluation value X by applying a predetermined weighting function to the created two-dimensional histogram H (A, S). Display means for displaying the abrasion resistance evaluation value X thus obtained.

The gray level signal detecting means in the device of the present invention irradiates the surface to be measured of the object made of a silicon-containing aluminum alloy with light from a light source, and the light reflected by each part of the surface to be measured is converted into a gray level signal by a detector. To detect. The detected gray level signal is a signal that continuously represents a gray state due to the difference in light reflectance between aluminum and silicon. This signal is a signal corresponding to the surface occupancy of aluminum and silicon on the surface to be measured, and therefore reflects the distribution state of primary crystal silicon in the aluminum alloy.

The binarizing means divides the gray level signal into two values, one representing the aluminum alloy region and the other representing the primary silicon region, with reference to a predetermined threshold value.
Quantify. As a method of setting the threshold value, there are a method of setting from the maximum value and the minimum value of the gray level signal, a method of creating a histogram of the gray level signal and obtaining the threshold value from this histogram. In the method of setting the threshold value from the maximum value and the minimum value of the gray level signal, the signal value becomes maximum when the measured region is occupied by the aluminum alloy region, and conversely, the measured region becomes the primary crystal silicon. When the area is occupied, the signal value becomes the minimum.
Therefore, a threshold value is defined between the maximum value and the minimum value. In this case, the threshold value is set so that the two binarized regions have a ratio of the actual aluminum region and the primary crystal silicon region.

On the other hand, when defects such as scratches are present on the surface to be measured, the maximum value and the minimum value may not be values corresponding to the aluminum alloy region and the primary crystal silicon region, respectively. In order to prevent this, a histogram of gray level signals is created, and the threshold value is set so that the ratio of the aluminum alloy region and the primary crystal silicon region in the entire measurement region becomes a predetermined value. The predetermined value is obtained from the content rate of each component in the silicon-containing aluminum alloy. By this method, the probability that the surface to be measured is the aluminum alloy region and the probability that it is the silicon region can be obtained. When the surface to be measured is large, the proportion occupied by each of the aluminum alloy region and the silicon region is actually the above probability. Therefore, when the surface to be measured is large, the method of obtaining the threshold value from the histogram is excellent. Further, according to this method, since it is not affected by defects such as scratches on the surface to be measured, the gray level signal can be accurately binarized into a numerical value representing the aluminum alloy region and a numerical value representing the silicon region.

In the histogram creating means, as described above, the surface to be measured is one-dimensionally scanned (that is, the surface to be measured is divided into a large number of linear stripes, and each linear stripe is scanned). The width A of the aluminum alloy region along the scanning line and the width S of the silicon region following the width A of the aluminum alloy region are measured as binarized data, and the measured values A, S A two-dimensional histogram H (A, S) with S as a parameter is created.

The wear resistance evaluation value calculation means calculates a wear resistance evaluation value X by applying a predetermined weighting function to the created two-dimensional histogram H (A, S). The form of the weighting function is not particularly limited as long as the wear resistance evaluation value X can be calculated from the two-dimensional histogram H (A, S). The abrasion resistance evaluation value X can be expressed by, for example, the following formula (1): X = [ΣΣA ² / (A + S) · H (A, S)] / ΣΣH (A, S) (1).

The wear resistance evaluation value X represented by the above equation (1) is derived from the following items. That is, the following relationship is established between the microscopic silicon distribution in the aluminum alloy region and the wear resistance. The smaller the ratio A / (A + S) occupied by the aluminum alloy region, the higher the wear resistance of the silicon-containing aluminum alloy. The smaller the width A of the aluminum alloy region, the higher the wear resistance of the silicon-containing aluminum alloy.

From the above two viewpoints, A ² / (A + S)
By acting as a weighting function for the two-dimensional histogram H (A, S), the wear resistance evaluation value X can be obtained. In this case, smaller X means higher wear resistance (harder to be worn), and larger X means lower wear resistance (more likely to wear).

The display means for displaying the abrasion resistance evaluation value X is
For example, it is not particularly limited as long as it can display the abrasion resistance evaluation value X such as a digital display or a personal computer. A plurality of display means may be used together.

In the apparatus of the present invention, the light source is a light source that emits light including an infrared wavelength region, the light receiver is a light receiver that can image reflected light from the surface to be measured, and the light source or the light receiver is It is preferable that a wavelength selection filter is provided, and the light source and the light receiver are arranged so as to be in a position of regular reflection with respect to the surface to be measured.

In the device of the present invention, the light source is a light source for irradiating parallel light including an infrared wavelength region, and is provided with a mask pattern, the mask pattern is a mask pattern which also serves as a wavelength selection filter, and the light receiver is a mask. It is also preferable to use a device that is a light receiver that detects the size and position of the pattern and can determine the position of the light source and the regular reflection with respect to the surface to be measured based on this information.

The shape of the surface to be measured is not particularly limited as long as it is smooth and applicable to this apparatus. An originally sufficiently smooth surface, for example, an inner surface of a cylinder of a cylinder block of an automobile engine can be measured as it is using the present apparatus.

The light source used in the device of the present invention is not particularly limited as long as it is a light source containing light of any wavelength from the visible light to the infrared wavelength range. For example, an LED, a normal fluorescent lamp, an incandescent lamp, or the like can be used. Since the difference in reflectance between aluminum and silicon becomes particularly large with respect to light having a wavelength in the infrared wavelength region, the light source that includes the infrared wavelength region is preferable as the light source.
In this case, a wavelength selection filter that transmits only light in the infrared wavelength region may be incorporated in the optical system so that only infrared light is transmitted.

The light source in the infrared wavelength range has a wavelength of 0.8 μm.
It is a light source that emits light containing electromagnetic waves of about -1000 μm, and the infrared wavelength range is 0.8 μm-2.5 μm.
m near infrared region, wavelength 2.5 μm-25 μm (normal) infrared region and wavelength 25 μm-1000 μm
Although it is subdivided into the far infrared region, a light source that emits light including the near infrared region or the (normal) infrared region is particularly preferable. In addition, a light source that emits parallel light is easy to use in practice.

Specific examples of the light source include lamps commonly used as a light source for generating light including an infrared wavelength region, such as a tungsten lamp, a glow bar lamp, and a Nernst lamp. The size and shape of the light source are appropriately selected in consideration of the size and shape of the surface to be measured.

The light receiver is not particularly limited as long as it is a light receiver capable of picking up an image of the reflected light from the surface to be measured. May be provided. As the light receiver, a commonly used image pickup device such as a CCD camera, or a one-dimensional light receiving element can be used. The size and shape of the light receiver are also optimally determined according to the surface to be measured.

If the light intensity of the light source is uneven, or if a uniform gray level signal cannot be obtained due to the characteristics of the light receiver such as the image pickup device, shading correction may be performed.

At least one type of wavelength selection filter may be provided in either the light source or the light receiver, but it is preferable that the wavelength selection filter is provided in the light source.

In using the apparatus of the present invention, when the surface to be measured is moving, for example, the surface to be measured is one surface on an article which is placed on a belt conveyor and sequentially conveyed, or the surface to be measured is When changing the irradiation angle from the light source to the surface to be measured according to the properties, the positional relationship between the light source, the surface to be measured, and the light receiver is set so that the light source and the light receiver are An attitude control mechanism capable of positioning so as to take the position of specular reflection is required.

The posture control mechanism is not particularly limited as long as it can achieve the object of the present invention, but as described above, for example, a suitable mask pattern may be provided on the light source. That is, the mask pattern imaged by the light receiver from the light source through the surface to be measured is matched with the mask pattern when the light source and the light receiver have positions of regular reflection with respect to the surface to be measured. Or by changing the position of the receiver,
The light source and the light receiver can be positioned so as to take the position of regular reflection with respect to the surface to be measured by following the movement of the surface to be measured. The drive means of the attitude control mechanism may be a conventional drive means.

It is very convenient that the mask pattern is a mask pattern which also serves as a wavelength selection filter.

[0030]

The gray level signal detecting means, the binarizing means, the histogram creating means, the wear resistance evaluation value calculating means, and the displaying means having the above-described constructions can be used to detect the wear resistance of the silicon-containing aluminum alloy and destroy the test object. Without doing
Easy and quick evaluation is possible.

[0031]

Embodiments of the present invention will be described below in more detail with reference to the drawings.

FIG. 1 shows a schematic configuration diagram of an embodiment of the device of the present invention. In FIG. 1, a light source 2 made of a fluorescent lamp is provided in the center of a cylinder block 1 which is an object to be inspected, and a wavelength selection for transmitting light in the infrared region also serving as a prism installed near the inner surface of the cylinder block 1 is selected. A filter 3 and a reflecting mirror 4 composed of a plane mirror that is installed so as to be inclined with respect to the inner surface of the cylinder block 1 are provided, and these are connected to a rotary table 6 that rotates according to a command from a computer 5.
A signal detecting device 9 including a convex lens 7 and a light receiving sensor 8 including a line sensor is further connected to the turntable 6 on the side opposite to the light source 2. The above-described elements (excluding the subject) constitute gray level signal detection means. The light receiving sensor 8 is electrically connected to a monitor 10 including a CRT, and a computer 5 including a binarizing unit (not shown), a histogram creating unit, an abrasion resistance evaluating unit, and a displaying unit.

A case will be described below in which the apparatus of the present embodiment having the above-mentioned structure is used for evaluating the wear resistance of the inner surface of the cylinder block 1 of a silicon-containing aluminum alloy automobile engine. In FIG. 1, a cylinder block 1 is provided by a light source 2.
The inner surface is illuminated, and the light reflected on the inner surface passes through the wavelength selection filter 3 and is further changed in optical path by the reflecting mirror 4. After that, the reflected light 11 enters the light receiver 12, passes through the convex lens 7, is received by the light receiving sensor 8, and becomes a gray level signal. Since the rotary table 6 rotates in the circumferential direction around the central axis 13 as indicated by an arrow, the linear light receiving sensor 8 can obtain a gray level signal for the entire circumference of the inner surface of the cylinder block 1. The obtained gray level signal is
It can be observed directly on the monitor 10.

The gray level signal is digitally converted by an A / D converter (not shown) and binarized by the binarizing means included in the computer 5. The resolution of the signal after digital conversion is 16 dots / mm and the gradation width is 16 bits. Further, a histogram gradation method was used to set the threshold value for binarization, and the ratio between the aluminum alloy region and the silicon region was set to 1: 2.

FIG. 2 shows a still image of the inner surface of the cylinder block 1 after binarization. In FIG. 2, the white area represents the aluminum alloy area 14, and the black area represents the silicon area 1.
Represents 5.

Next, in the histogram creating means, the surface to be measured is one-dimensionally scanned, so that the width A of the aluminum alloy region 14 along the scan line and the silicon region 15 following the width A of the aluminum alloy region 14 are scanned. A width S and a two-dimensional histogram H obtained by measuring the binarized data and using the measured values A and S as parameters based on the measured values A and S.
Create (A, S). This method will be specifically described.
That is, for example, as shown in FIG.
By scanning along a ', the one-dimensional scanning data shown in FIG. 3 is obtained as the binarized data. Focusing on the w region in the one-dimensional scan data, the silicon region 15 and the aluminum alloy region 14 are arranged in the order of widths S ₁ , A ₁ , S ₂ and A ₂ . Therefore, in this case H
One is added to (A ₁ , S ₁ ) and H (A ₂ , S ₂ ).
Using the same method, the above scanning is repeated along the scanning lines set at predetermined intervals to obtain the two-dimensional histogram H (A, S) for the entire area shown in FIG.

In the abrasion resistance evaluation value calculation means, A ² / (A is calculated for the two-dimensional histogram H (A, S).
The wear resistance evaluation value X is calculated by the following equation (1) which performs weighting calculation with + S) as a weight. X = [ΣΣA ² / (A + S) · H (A, S)] / ΣΣH (A, S) (1)

The abrasion resistance evaluation value X is displayed on the display device.
In this case, the display device used is appropriately selected from those capable of displaying the abrasion resistance evaluation value, such as a digital display or a personal computer.

<Abrasion resistance evaluation test> In the same manner as described above, a wear resistance evaluation test was performed on the inner surface of the cylinder of a plurality of silicon-containing aluminum alloy automobile engine blocks having different properties using the apparatus of this embodiment. It was That is,
Twelve kinds of silicon-containing aluminum alloy automobile engine blocks having a predetermined silicon content ratio and different silicon distribution states were prepared, and the inner surface of the cylinder block was scanned using the apparatus of the present embodiment to evaluate the wear resistance. I asked for X. The scanning region was the entire circumference of 64 mm in the depth direction from the vicinity of the piston ring top dead center of the cylinder block. Next, an engine was constructed with the engine block, and a bench test was conducted under predetermined conditions. After that, the stepped wear depth of the inner surface of the cylinder block was measured at a position near the top dead center of the piston ring with a surface roughness measuring device and used as the wear amount.

FIG. 4 shows the wear resistance evaluation value X (vertical axis) and the wear depth of the cylinder block inner surface after the bench test (horizontal axis).
Shows the relationship with. As is clear from FIG. 4, there is a correlation between them (correlation coefficient r = 0.731). From this, it is understood that it is possible to non-destructively evaluate the wear resistance of the silicon-containing aluminum alloy using the apparatus of this example.

[0041]

As described above, the wear resistance evaluation apparatus for a silicon-containing aluminum alloy of the present invention has a gray level signal detection means, a binarization means, a histogram creation means, and a wear resistance evaluation value calculation having a predetermined configuration. Since it is provided with the means and the display means, the wear resistance of the silicon-containing aluminum alloy can be easily and quickly evaluated without destroying the specimen, which is useful for product development and product quality control.

Further, when the apparatus of the present invention is used, it is not necessary to touch the surface to be measured at the time of measurement, and the geometrical restriction on the surface to be measured is greatly reduced. Therefore, the device of the present invention can be widely applied to various industrial fields.

Further, the wear resistance evaluation data of the silicon-containing aluminum alloy measured by using the apparatus of the present invention is as follows:
For example, since it can be stored in a memory of a computer and subjected to arbitrary processing, it has a great effect on analysis and research of an object to be measured, and it is easy to copy, transmit, store, manage, etc. the information.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a wear resistance evaluation apparatus for a silicon-containing aluminum alloy of the present invention.

FIG. 2 is a micrograph of a metal structure of an inner surface of a silicon-containing aluminum alloy cylinder block after binarization using the apparatus of the present invention.

FIG. 3 is a diagram showing binarized one-dimensional scan data taken along the scanning line aa ′ in FIG.

FIG. 4 is a diagram showing a relationship between a wear resistance evaluation value X and a wear depth of an inner surface of a cylinder block after a bench test.

[Explanation of symbols]

 1 Cylinder Block 2 Light Source 3 Wavelength Selection Filter 4 Reflector 5 Computer 6 Rotating Table 7 Convex Lens 8 Light-Reception Sensor 9 Signal Detection Device 10 Monitor 11 Reflected Light 12 Light-Receiver 13 Center Axis 14 Aluminum Alloy Region 15 Silicon Region

Front Page Continuation (72) Inventor Takashi Wada, Nagakute-cho, Aichi-gun, Aichi Prefecture 1-41 Yokomichi, Yokosuka, Central Research Institute of Toyota Corporation (72) Inventor, Morihiro Matsuda 41, Nagakute, Nagakute-machi, Aichi-gun, Aichi Address 1 Inside Toyota Central R & D Co., Ltd. (72) Inventor Ryuichi Masuda 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd. (72) Inventor Yoshio Yukino 1 Toyota Town, Aichi Prefecture Toyota Auto Vehicle Incorporated (72) Inventor Tadashi Oyama 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (2)

[Claims] 1. A surface to be measured obtained by irradiating a smooth surface to be measured made of an aluminum alloy containing silicon with light from a light source and detecting reflected light reflected by the surface to be measured with a light receiver. A device for evaluating the wear resistance of a silicon-containing aluminum alloy based on distribution information on silicon and aluminum alloys, which is based on the difference in light reflectance between the aluminum alloy and silicon A gray level signal detecting means for detecting an alloy region and a silicon region as a gray level signal, and a detected gray level signal with a numerical value representing an aluminum alloy region and a numerical value representing a silicon region with reference to a predetermined threshold value. Binarizing means for binarizing the and, and the aluminum surface along the scanning line by one-dimensionally scanning the surface to be measured. The width A of the alloy region and the width S of the silicon region following the width A of the aluminum alloy region are measured from the binarized data, and the measured values A and S are used as parameters based on the measured values A and S. 2 Dimensional histogram H
Histogram creating means for creating (A, S), and wear resistance evaluation value for calculating wear resistance evaluation value X by applying a predetermined weighting function to the created two-dimensional histogram H (A, S) A wear resistance evaluation apparatus for a silicon-containing aluminum alloy, comprising: a calculation means and a display means for displaying the calculated wear resistance evaluation value X. 2. A wear resistance evaluation value X is expressed by the following equation (1): X = [ΣΣA ² / (A + S) · H (A, S)] / ΣΣH (A, S) (1) The wear resistance evaluation device for a silicon-containing aluminum alloy according to claim 1.