JPH0475763A - Surface treated fiber reinforced metal and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain highly reliable fiber reinforced metal with no detachment of film by forming metallic matrix, reinforcing fibers embedded in this metallic matrix and projecting a part thereof on the matrix surface and the film on the matrix surface so as to embed the fibers. CONSTITUTION:This surface treated FRM 1 is produced by etching the surface over one or more layers as fiber layer form the surface in the range that the reinforcing fiber 2 on the FRM surface is not detached, in the etching process, and after that, in the film forming process, forming the film 4 with plating, etc., and embedding the projecting reinforcing fiber in there. In the surface treated FRM 6 manufactured in such way the film replaces the metallic matrix on the surface layer of FRM, i.e., the FRM 6 is formed integrally in a mechanically engaging condition that the film with the fiber by embedding the projecting reinforcing fiber in the film. Therefore, the joined strength of film becomes sum of stuck strength between the film and the metallic matrix and mechanical engagement force between the film and the reinforcing fiber, and even to heat cycle and heat impact, the detachment of film is not developed and the high reliability can be obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a surface-treated fiber-reinforced metal (hereinafter referred to as FRM) in which a film is formed on the surface thereof, and a method for producing the same. The present invention relates to a surface-treated fiber-reinforced metal that is highly reliable as a material for parts related to aircraft, space, and electronics, and a method for producing the same.

[Conventional technology]

FRM is a metal matrix reinforced with reinforcing fibers made of one or more types of carbon fibers or ceramic fibers such as silicon carbide, silicon nitride, and alumina.
Compared to conventional metal parts, it is lighter and has superior strength and rigidity, and is highly expected to be used in the fields of aviation, space, and engineering/ctronics. Among the materials used in the electronics field, those that require reliability in terms of electrical conductivity, conductivity, corrosion resistance, bondability, etc. usually undergo surface treatment on the material surface, and FRM is used in other fields. In this case, surface treatment is also required. However, no surface treatment suitable for FRM has been developed; for example, surface treatments for metals and alloys that have been used in the past, as shown in "Plating Technology Handbook" (Nikkan Kogyo Shimbun), pages 143-149, have not been developed. It is generally left as is.

FIGS. 4 and 5 are cross-sectional views schematically showing conventional surface-treated FRMs, respectively. In the figure, (1) is FR
In M, reinforcing fibers (2) made of carbon fibers or ceramic fibers are embedded and integrated into a metal matrix (3) made of a single metal or alloy matrix. 6 (4) is a plating layer as a film, which is formed directly on the surface of FRM (1) in Fig. 4, and is formed directly on the surface of FRM (1) in Fig. 5.
It is formed on the matrix single layer (5) formed on the surface of (1). (6) is a surface treated FRM formed by these.

The formation of the plating layer (4) is performed by a conventional surface treatment method consisting of steps such as ■polishing, ■degreasing, ■etching, ■activation, ■base plating, and zero-line plating.
As shown in the figure, it is usually formed directly on the surface of the FRH. Such a plating layer (4) has a low bonding strength with the reinforcing fiber (2) made of carbon fiber or ceramic fiber. Therefore, peeling occurs between the plating layer (4) and the FRM (1) due to thermal cycles and thermal shock.

Further, as shown in FIG. 5 4r, FRM manufacturing stage N12.
- When a single 71 helix layer (5) is formed on the surface and a plating layer (4) is formed on the surface, it is effective for parts with relatively simple shapes, but it is effective for parts with relatively simple shapes. When molding a shaped FRM (1), secondary processing is unavoidable, and as a result, the reinforcing fibers (2) are exposed and a plating layer (4) is formed on its surface. . Therefore, in such a portion, peeling occurs between the plating layer (4) and the FRM (1), as described above.

In this way, conventional surface-treated FRM
There was a problem in that the film formed on the RH, such as the plating layer (4), lacked reliability.

[Problem to be solved by the invention]

The present invention was made to solve the above-mentioned problems, and the bonding strength between the film formed by surface treatment and the FRH is high, and the film does not peel off even when subjected to thermal cycles or thermal shock. The object of the present invention is to provide a highly reliable surface-treated fiber-reinforced metal and a method for producing the same.

[Means to solve the problem]

The present invention is the following surface-treated fiber-reinforced metal and its manufacturing method.

(1) A metal matrix, reinforcing fibers embedded in the metal matrix and partially protruding from the surface of the metal matrix, and a metal 7 such that the protruding reinforcing fibers are embedded.
(2) the diameter of the reinforcing fibers so that the reinforcing fibers protrude from the surface of the fiber-reinforced metal in which the reinforcing fibers are embedded in the metal matrix; A surface treatment consisting of an etching process in which the metal matrix is etched to an etching depth of 1.5 to 6 times the etching depth, and a film forming process in which a film is formed on the surface of the fiber-reinforced metal so as to embed the protruding reinforcing fibers. In the method for producing fiber-reinforced metal of the present invention, examples of the metal matrix include aluminum, aluminum alloys, magnesium, magnesium alloys, titanium, titanium alloys, single metals, and alloys thereof.

In addition to carbon fibers, ceramic fibers such as silicon carbide, silicon nitride, and alumina are preferable as reinforcing fibers.
Other fibers may also be used.

The film may be any film that has good bonding properties with the metal matrix, and is generally a plating layer, but may also be a metallizing layer or other film.

The surface-treated FRM of the present invention is an FRM in which reinforcing fibers are embedded in a metal matrix so that some of them protrude from the surface.
A film is formed on the surface of the RH so that the protruding reinforcing fibers are embedded in the film.8 In the manufacturing method of the present invention, various methods and techniques are used in the etching process of the FRM depending on the type of FRM. Although conditions can be adopted, this etching process is performed so that the reinforcing fibers protrude from the FRM surface. At this time, processing is performed such that the amount of etching is increased to the extent that one reinforcing fiber does not fall off compared to conventional etching.

Methods for this include increasing the etching time compared to the conventional etching time for single metals, changing the concentration of the etching solution, increasing the humidity of the etching oil compared to the conventional method, and (2).

A method that combines these methods can be adopted. At this time, the etching depth from the surface of the FRM is 1.5 of the diameter of the 5 reinforcing fibers.
1. So that the range is -6 times. : Etching the metal matrix.

If the etching depth is less than 1.5 times the diameter of the reinforcing fibers, peeling will occur between the reinforcing fibers and the film due to AJ and thermal shock, similar to conventional surface treatment methods.

Furthermore, when the etching depth exceeds 6 times, although no peeling due to thermal shock is observed, reinforcing fibers fall off during surface treatment and reinforcing fiber numbers on the FRM surface become disordered.

In the present invention, after performing the above etching process,
In this film forming process, a film is formed to replace the metal matrix removed by etching, and the protruding reinforcing fibers are embedded in the film. , plating and other methods can be employed.

For example, when plating is not applied to FRM that uses aluminum or aluminum alloy as a metal matrix, zinc substitution can be performed and a nickel base plated (
zincate method). In addition to this zincate method, surface treatments including etching steps such as bondal method, anodizing method, and galvanizing method can also be applied. Pre-treatments such as these can be performed. In addition, before the film formation process, 9 surface activation treatments, adhesion improvement treatments,
Pretreatment such as base plating can be applied.

[For production]

The surface-treated FRM according to the present invention has the following characteristics: in the etching process, the reinforcing fibers on the FRM surface do not fall off;
One or more fiber layers are etched from the surface, and then in a film forming step, a film is formed by plating or the like, and the protruding reinforcing fibers are embedded in the film.

The surface-treated FRM manufactured in this way has a form in which the film replaces the metal matrix on the surface layer of the FRH, that is, the film embeds the protruding reinforcing fibers and is integrated in a mechanically engaged state. . Therefore, the bonding strength of the coating is the sum of the bonding strength between the coating and the metal matrix, as well as the mechanical engagement force between the coating and the reinforcing material, and is much greater than that of the conventional method.

〔Example〕

Examples of the present invention will be described below.

Figure 2 is a cross-sectional view schematically showing the surface-treated FRM of the example. In Figure 2, the same reference numerals as in Figures 4 and 5 indicate the same or equivalent parts.
The FRM (1) is formed by reinforcing fibers (2) embedded in a metal matrix (3), and the FRM (1) is formed so as to embed reinforcing fibers (2a) protruding from the surface of the FRM (1). It is formed from a plating layer (4) as a coating.

FIG. 2 is a process diagram showing the manufacturing method according to the Jingu l-method of the example.

The manufacturing method of the surface-treated FRM (6) includes a polishing step (11) of the surface of the FRM (1), a water washing step (12), a degreasing step (13) of the FRM (1) after polishing, and a water washing step (14). ,
Etching process (15), water washing process (16), surface activation process (17), water washing process (18), FR after activation
Surface treatment FRM (
6) is manufactured.

Next, 1 reinforcing fiber (2
) as carbon fiber (manufactured by Toshiku Co., Ltd., M406 product name),
FRM (1) is made by high pressure casting method (molten metal forging method) using industrial pure aluminum as the metal matrix (3).
The fiber volume fraction (Vf) was 60%. Using this FRM, nickel plating was performed by the zincate method shown in Fig. 2 to form a plating layer (4).
The surface-treated FRM (6) shown in FIG. 1 was manufactured.

First, in the polishing step (11), the surface of the FRM (1) is polished with #600 emery paper, and then the water washing step (1
In 2), cleaning was performed using an ultrasonic cleaner. The FRM (1) after cleaning was washed in trichlorethylene in a degreasing step (13), and after a water washing step (14), an etching step (15) was performed. Etching was performed by heating a mixed solution of sodium carbonate and sodium phosphate as an etching agent, and immersing the FRM in the mixed solution. At this time, experiments were carried out by changing the etching agent to various mixing ratios, heating temperature and dipping time under various conditions, and examining the influence of etching depth to find appropriate conditions. After etching, an activation step (17) was carried out by immersing it in 50% nitric acid for 30 seconds at room temperature, followed by a zinc substitution step (19), in which it was subjected to a Jingu 1 treatment. After the Jingu 1 treatment, in the plating step (20), nickel plating was performed using the same method as conventional chemical nickel plating.

FIG. 3 is a micrograph showing the metal structure of the obtained surface-treated FRM (6). When surface treatment is performed using the above method under appropriate etching conditions, as shown in Figure 3,
A splicing layer is embedded over several reinforcing fiber layers from the FRM surface so as to wrap each reinforcing fiber, and a metal matrix is replaced to form a surface-treated FRM.

The etching conditions at this time were to heat a mixed solution of 20 to 50 g/Q of each of sodium carbonate and monolithium phosphate to 50 to 90°C, and immerse it for 1 to 5 minutes.

Ta. The plated layer obtained under such etching conditions has a thickness of 1.5 to 6 times the diameter of the reinforcing fiber.

Next, the results of testing the bonding strength of plating on the surface-treated FRH obtained will be explained.

The test conditions are as follows.

■Heat sanitization test: After holding at a temperature of 150°C for 1 hour, it was placed in cold water.

■Peel-off test: A metal with an area of 4 nm2 is soldered onto the plated surface, and after introducing a cut with a sharp knife, the peel-off load is measured.

As a result, as a condition regarding the etching depth, the S degree of 1-lium carbonate and 1-lium phosphate was 20-5.
0g/Q, keep the cup temperature at 50=90'CLn,
FRM was immersed in the solution for 5 minutes and then surface treated.
Even when the surface of RM was observed using a looper in the thermal sanitary test, no blisters were observed on the surface of the plating layer.

In addition, in the peeling test, a value of 2-2.6 kgf/m2 of garden was obtained.

From the above results, the above surface treatment FR1'! The bonding strength of the plating layer is high, and it is formed by a surface treatment method that is different from that of conventional FRMl, and it has a significantly superior bonding strength compared to the peeling test of 0°1-0°5kgf/7. It can be seen that it is. Such surface treatment F
RM can be put into practical use by further applying gold plating.Next, another example 1. Explain about the knee.

As reinforcing fibers, carbon fibers are cut into lengths of 0°6 mm on average and randomly oriented in three dimensions (VfO
73) was used as an FRM with aluminum as a matrix. In this example, the same etching process was applied, as in the case of the above-mentioned actual case, in which the material was polished and washed, then washed in 1-lichlorethylene, and then washed with water. We conducted experiments using various mixing ratios and concentrations of etching agents, as well as heating temperatures and immersion times, and investigated the effects of etching depth to find the best conditions.

The etching depth increases as the etching agent concentration, heating temperature, immersion time, etc. increase, but if the etching depth is not adjusted properly, the fibers will fall off or the orientation will be disturbed.

As a result, the conditions regarding the T-zing depth were such that the concentrations of 1-lium carbonate and 1-lium phosphate were 20 to 20%.
The plating layer obtained by immersing the FRM in a solution containing 30 g/U and maintained at a temperature of 50 to 70°C for 1 to 2 minutes shows no blistering on the surface of the plating layer even when the surface is observed with a magnifying glass in the heat #1 test. In addition, in peel test number -4, values of 2.3 to 3 kHz/111 m2 were obtained. In the case of this example, it is thought that the existence of short fibers in the plating layer with an orientation close to perpendicular to the surface of the plating layer caused a pinning effect and improved the bonding strength between the plating layer and the FRH. .

From the above results, the surface treatment according to the present invention is practically very effective not only for continuous fiber FRM but also for short fiber FRH, and is effective for plating layers produced by conventional surface treatment methods for FR. Compared to.

It can be seen that the bonding strength is excellent. This surface treatment FR
Similarly to the case of continuous fibers, M can be further applied with gold plating for practical use.

In the above example, the reinforcing fibers were made to protrude by etching, but it can also be applied to surfaces where the fibers have already been evaporated, and it can also be applied to parts cut into complex shapes by cutting. be.

〔Effect of the invention〕

In the surface-treated FRM of the present invention, the reinforcing fibers protrude from the metal matrix and are embedded in the film, so that the reinforcing fibers protrude from the metal matrix and are embedded in the film.
The bonding strength of RM is high, and the film does not peel off even under thermal cycles and thermal shocks, providing high reliability.

Further, the method for manufacturing a surface-treated FRH of the present invention can easily and efficiently manufacture an excellent surface-treated FRM as described in 6.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view schematically showing the surface-treated FRM of the example, Fig. 2 is a manufacturing process diagram, Fig. 3 is a micrograph showing the metal structure, and Figs. 4 and 5 are conventional surface-treated FRMs. It is a sectional view showing typically. In each figure, the same reference numerals indicate the same or corresponding parts, (1)
is FRM, (2) and (2a) are reinforcing fibers, (3) is metal matrix. (4) is plating layer,

Claims (2)

[Claims] (1) A metal matrix, reinforcing fibers embedded in the metal matrix and partially protruding from the surface of the metal matrix, and a film formed on the surface of the metal matrix to embed the protruding reinforcing fibers. A surface-treated fiber-reinforced metal characterized by: (2) Etching in which the metal matrix is etched to an etching depth of 1.5 to 6 times the diameter of the reinforcing fibers so that the reinforcing fibers protrude from the surface of the fiber-reinforced metal in which the reinforcing fibers are embedded in the metal matrix. 1. A method for producing a surface-treated fiber-reinforced metal, comprising a step of forming a film on the surface of the fiber-reinforced metal so as to embed the protruding reinforcing fibers.