JPH01222030A - Fiber reinforced member - Google Patents

Abstract

PURPOSE:To obtain a fiber reinforced member of high strength by imbedding into a matrix the reinforced fiber consisting of the ultrahigh strength metal fine wire of the fiber like fine metal structure of a specified microcell obtd. by executing the cold wire drawing of a wire rod. CONSTITUTION:The wire rod composed of a Fe-C-Si-Mn ferrous alloy, etc., is strongly worked at about >=4 working distortion by cold wire drawing after the heat treatment cooling it by heating at about 700-1,100 deg.C. The fine wire having the fiber like fine metal structure in which the ultrafine cell of 5-100Angstrom is fiber likely arranged in one direction at fiber intervals 50-1,000Angstrom and <=160mum wire diameter and 300-600kgf/mm<2> is obtd. This ultrahigh strength metal fine wire, the stranded wire twisting it in plural pieces or the yarn doubling subjected to sizing processing is taken as the reinforcing fiber. Either of this monofiber like reinforced fiber, the reinforced cloth weaving it or the reinforced net made in a wire gauze is embedded in a matrix resin or metal. The FRP, FRM drastically improving the strength by using the reinforced fiber improving the tensile strength are thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a fiber reinforced member, that is, a fiber reinforced resin (F R
P) or fiber reinforced metal (FRM), FRP, FRM, which has significantly improved strength by using ultrafine metal wires with a new fibrous fine metal structure as reinforcing fibers.
Regarding RM.

[Conventional technology]

Glass fibers, carbon fibers, aramid fibers, alumina fibers, boron fibers, piano ultra-fine wires, stainless steel ultra-fine wires, etc. have traditionally been used as reinforcing fibers for FRP and FRM, and epoxy resins and phenol resins have been used as matrix resins. , polyimide resin, etc., and A1°Mg, Ti, Cu, etc. are used as the matrix metal.

Such reinforcing fibers for FRP and FRM have several uses:
It is necessary to make the tensile strength as high as possible, and various reinforcing fibers with improved tensile strength have been proposed.
For example, the aramid fiber mentioned above.

Piano m-wire has a tensile strength of 300 kgf/mm2.

[Problem that the invention seeks to solve]

By the way, recently, FRP and FRM have been used in a very wide range of applications, and in some cases, those reinforced with the various reinforcing fibers mentioned above may not be strong enough, so it is recommended to use reinforcing fibers with higher tensile strength. is requested.

The present invention was made in response to the above-mentioned conventional demands, and an object of the present invention is to provide FRP and FRM with significantly improved strength by improving the tensile strength of reinforcing fibers.

[Means for solving problems]

In order to achieve the above object, the present inventors have continued to conduct extensive research on metal structures that can significantly improve the tensile strength of the reinforcing fibers, and have discovered the following points.

That is, the wire is made of a Fe-C-3i-Mn iron-based alloy and has a composite metal structure in which a low-temperature transformation phase consisting of acicular martensite, bainite, or a mixed structure thereof is uniformly dispersed in a ferrite phase. has excellent strong workability, and by using a wire having such a metal structure, it is possible to easily and reliably obtain an ultrafine wire with a wire diameter of 160 μm or less by cold wire drawing.

If such a wire is strongly worked to a working strain of 4 or more by cold wire drawing, a uniform fibrous fine metal structure in which the above-mentioned ferrite phase and low-temperature transformation formed phase are combined and extends in one direction is formed. The ultra-fine wires formed and having such a metal structure have a tensile strength of 300-600 kg f/m
” and found that the toughness was comparable to that of conventional piano wire and stainless steel wire.

Such a fibrous fine metal structure is a completely new structure that has not been previously known. The present inventors believe that the fibrous fine metal Mi weave is the main reason for improving the tensile strength. As a result of further research on the reinforcing mechanism, it was found that in the metal structure with ultra-high strength as described above, the spacing between the fibers is 50 to 1000, and the fibrous composite structure has a spacing of 5 to 100. It was discovered that it is composed of human ultrafine cells.

Therefore, the present invention provides a method for embedding either a monofilament reinforcing fiber, a reinforcing woven fabric obtained by woven the reinforcing fiber, or a reinforcing net formed by reticulating the reinforcing fiber into a matrix resin or a matrix metal. In the fiber-reinforced member, the reinforcing fibers are formed by strongly processing a wire rod by cold wire drawing, and 5 to 100 ultrafine cells produced by the strong processing are arranged in a fibrous shape in one direction, And the fiber spacing is 50 to 50 to 100% fibrous fine metal & wire diameter 160μ- with 11 weaves.
The following is an ultra-high strength metal wire with a tensile strength of 300 to 600 kgf/m''.

It is characterized by being a stranded wire made by twisting a plurality of the ultrafine wires together, or a doubled yarn made by combining a plurality of the ultrafine metal wires and subjecting them to sizing treatment.

Matrix resin of reinforcing fibers in the present invention.

There are various ways to bury the wire in the metal, for example, as a single wire,
Alternatively, this can be made into twisted wires or double yarns and buried, or even single wires, twisted wires, and double yarns can be made into woven fabrics.

Alternatively, it may be buried in a netted state, and not only the ultrafine metal wire of the present invention may be buried, but also a combination with conventional stainless steel wire, piano wire, etc. may be buried.

Here, a method for manufacturing ultra-high strength metal ultrafine wire for reinforcing fibers in FRP and FRM of the present invention will be explained.

First, in weight percent, C: 0.01 to 0.50%, Si: 3
．． 0% or less, Mn: 5.0% or less, the balance is Fe and unavoidable impurities, and the wire diameter is 3.5W or less.
After heating to a temperature in the range of 1100°C, the mixture is cooled (this heating and cooling may be performed multiple times) to produce martensite, bainite, or a mixture thereof, which may contain some residual austenite. A wire rod having a composite structure in which a low-temperature transformation-generated phase consisting of a structure is uniformly dispersed in a ferrite phase at a volume fraction in the range of 15 to 75% is manufactured. This manufacturing method is disclosed in Japanese Patent Application Laid-Open No. 62-20824.
It is stated in the No.

Next, the composite texture wire rod obtained in this way is subjected to strong processing by cold wire drawing to a processing strain of 4 or more, preferably 5 or more, to combine the ferrite phase and the low-temperature transformation generation phase,
Forms a fine fibrous structure that extends continuously in one direction as a metallographic structure. By increasing the degree of processing in this way, the fibrous &ll; weave becomes finer, the fiber spacing becomes narrower, and finally the size of the cells generated during processing as described above.

A fibrous fine metal structure is obtained in which the fiber spacing is 5 to 100 people and 50 to 100 people, respectively. Note that in a thin wire obtained by wire drawing with a processing strain of less than 4, the fibrous structure is in the middle of development and the structure is incomplete, and therefore the strength is low.

FIG. 8 compares the tensile strength and toughness of the ultra-high-strength metal wire for reinforcing fibers of FRP and FRM of the present invention with conventional piano wire, etc. From the figure, it can be seen that the metal wire of the present invention has the following properties: Its tensile strength has been dramatically improved compared to piano wire, etc.
Moreover, it can be seen that the toughness is equivalent to that of piano wire, etc. Moreover, FIG. 9 is a scanning electron micrograph of the ultrafine metal wire for reinforcing fiber of the present invention that has been strongly processed to a processing strain of 5 or more (area reduction rate of 99.5%) by the above method, and is continuous in one direction. ~
A fibrous fine metal structure extending in the area is observed. 1st
Figure 0 is a photograph of the above fibrous structure observed using an ultra-high voltage electron microscope (3MV).
Ultra-fine human cells can be seen.

Next, the reasons for setting various conditions in the above manufacturing method will be explained.

C: In order to obtain the fibrous fine metal structure according to the present invention and the above tensile strength, it is necessary to control the amount of C added,
As a result of experiments, it was found that a range of 0.01 to 0.50% is appropriate.

Si: Si is effective as a reinforcing element for the ferrite phase, but if it is added in excess of 3.0%, the transformation temperature will shift to a significantly higher temperature side, and decarburization of the wire surface will likely occur, so the amount added is The upper limit is 3.0%.

Mn: Mn has the effect of strengthening ultra-fine wires and increasing the hardenability of both of the above phases, but this effect is saturated if added in excess of 5.0%, so the upper limit of the amount added is It shall be 5.0%.

In addition, elements whose content is preferably regulated, elements that may be added, unavoidable impurities, etc. will be explained.

H is a harmful element that embrittles steel, and the higher the strength, the greater the effect, so in the present invention, H
It is best to limit the amount to I PPM or less, particularly preferably 0.5 PPM. Methods for reducing the amount of H include degassing treatment in molten steel, hot rolling into wire rods, cooling control after heat treatment, and low temperature. Measures such as dehydrogenation control are effective.

In the present invention, in order to refine the metal structure of ultrafine wires, N
At least one element selected from b, V, and Ti can be added. Each of these elements needs to be added in an amount of 0.005% or more in order to refine the structure.
If added in excess, the effect will be saturated and it will be economically disadvantageous, so the upper limit is set at 0.5%.

Unavoidable impurities include S, P, N, and AI.

etc.

In order to reduce the amount of MnS, S is preferably set to 0.005% or less, thereby further improving ductility. On the other hand, it is also preferable to adjust the shape of the MnS inclusions by adding rare earth elements such as Ca and Ce.

Since P is an element with significant grain boundary segregation, it is preferable that its content be 0.01% or less.

N is the element that is most easily aged when it exists in a solid solution state, and it ages during processing and inhibits workability, and ages after processing and deteriorates the ductility of the ultra-m wire obtained by wire drawing. , preferably 0.003% or less.

AI forms oxide-based inclusions, and these inclusions are difficult to deform and impede the workability of the wire, so it is usually 0.01
% or less, and the Si/
When the AJ ratio increases, the number of silicate inclusions increases. In particular, when the amount of 611 is small, the number of silicate inclusions increases rapidly, which not only deteriorates the wire drawability but also reduces the quality of the ultrafine wire obtained by wire drawing. Deteriorates the properties of. Therefore, in the present invention, St/A! The ratio is preferably 1000 or less, particularly preferably 250 or less.

The reason why the volume fraction of the low-temperature transformation product phase in the ferrite phase is in the range of 15 to 75% in the composite structure of the wire is as follows. If it is less than 15%, it is possible to obtain an ultra-fine wire under a 160μ steel plate by cold drawing a wire having such a composite structure, but the obtained ultra-fine wire has a metal structure similar to that of the above-mentioned fibrous fine metal. &ll weave, the fibrous structure is incomplete, and the tensile strength is less than 300 k (f/n+"). On the other hand, the volume fraction of the low-temperature transformation formed phase in the ferrite phase is 7.
If the amount is more than 5%, the wire is likely to break during wire drawing, and even if the wire can be drawn without breaking, the resulting ultra-fine wire will have a fine fibrous structure, as in the case of 15% or less. It has no structure, has an incomplete fibrous U weave, and has a tensile strength of 30
0 ktf/Ryu 2 or less 2 or less.

Regarding the volume fraction in the above-mentioned wire, the wire diameter and volume fraction of the wire are regulated depending on the form of the phase formed by low-temperature transformation, that is, whether the phase is mainly acicular or mainly lump-like. Ru. Note that here the needle-like (elong)
"Ated" or "Bcicular" means that the particles have directionality, and "globular" means that the particles do not have directionality.

That is, when 80% or more of the low-temperature transformation product phase is acicular, the volume fraction of the low-temperature transformation product phase is 50% or less, and the wire diameter is 3.
．． 5H or less, and if 80% or more is lumpy,
The volume fraction needs to be 50% or less, and the wire diameter needs to be 2.0 u or less. In addition, when the low-temperature transformation product phase has a mixed structure of needle-like and lump-like structures, the volume fraction is 75% or less, and the wire diameter is 3.5%.
It needs to be less than wm. Note that the lower limit of the wire diameter that the wire rod should have is not particularly limited, but considering the current processing technology, it is usually 0.3 mm.

[Effect]

According to the FRP and FRM according to the present invention, the ultra-fine metal wires used for the reinforcing fibers are
The processing cells of 100 people are arranged in a fibrous manner in one direction, and the fiber spacing forms a fibrous fine metal structure of 50 to 1000 people, and as explained in the reinforcement mechanism above, 300 to 600 ktf. /fl''. Therefore, the strength of FRM etc. can be dramatically improved.

Furthermore, the ultrafine metal wire for reinforcing fibers of the present invention has excellent cold workability, and by appropriately selecting the wire diameter and processing degree of the wire, wires of 160 μm or less can be easily and reliably obtained. Therefore, for example, it is easy to use wires with a diameter of 10 to 100 μm and twist or double them, and it is also easy to use them to make woven fabrics or nets. Yes, if you do it like this, the fiber direction is vertical.

Since it lies on its side, the strength not only in the -axial direction but also in the two-wheel direction can be improved.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 are diagrams for explaining an FRP according to an embodiment of the present invention.

In Fig. 1, 1 is FRP, which is a matrix resin 2 made of epoxy resin with wire mesh reinforcement w43.
It becomes buried. This reinforcement w43 is vertical.

It is made by plain weaving horizontally twisted wires 4.5 on a wire mesh loom, and each twisted wire 4.5 is made by twisting 2 to 100 ultra-fine metal wires 6 of 10 to 100 μm each, Each of the strands is bent into a wave shape and knitted at a predetermined mesh interval. Although not shown, the horizontally twisted cotton 5 is inverted inward at the left and right ends of the reinforcing net 3, and the inverted portions are continuous without being cut.

In FIG. 1, the FRM is constructed by changing the matrix resin 2 to a matrix metal made of Al.

Each metal extra-fine vA6 for the reinforcing net 3 has a weight percentage of C: 0.
．． 01-0.50%, Si: 3.0% or less, Mn:
5. A wire rod with a wire diameter of 2.5 fl or less consisting of 0% or less, the balance Fe and unavoidable impurities is cold drawn to a wire diameter of 1.
It is produced by strong processing to a size of 60 μm or less, and the processed cells formed by the strong processing form a fibrous fine metal structure in which the processed cells are arranged in a unidirectional fibrous shape, and the size of the processed cells is Fiber spacing is 5-100 and 50-1, respectively.
000 people, and the strength is 300~60Q klr
4/ws" ultra-high strength metal ultrafine wire.

As described above, since the ultra-fine metal wire 6 of this embodiment can be made with a very small diameter, even a single wire of this wire has superior ductility compared to conventional piano wire, etc., and furthermore, multiple wires of small diameter can be stranded. This further improves the ductility and allows the wire mesh to be formed into a wire mesh using a wire mesh knitting machine, without causing cracks or wire breakage at the reversed portions of the horizontal wires.

The strength of the metal ultrafine wire 6 used in the reinforcing net 3 of FRPI and FRM in this embodiment is 300 to 600.
kgf/1m2, which is a dramatic improvement compared to conventional stainless steel wire and piano wire.
The strength of RM can be improved.

Next, the wire diameter of 160μm or less and the tensile strength of 300~
An experimental example in which an ultrafine metal wire of 600 kgf/m'' was manufactured will be described.

2. First, a wire having the chemical composition shown in Table 1 and a wire diameter of 0.9 to 2.5 vs. shown in Table 2 was continuously heated and quenched at a temperature of 890°C, and then Continuous heating at 810℃.

After cooling, a composite wire rod having a two-phase MHIj consisting of a ferrite phase and a martensitic phase partially containing residual austenite was obtained. Then, this composite textured wire rod was drawn into ultra-fine wires having the wire diameters shown in Table 2 by cold wire drawing. In this Table 2, numbers 1 to 9 can be employed as the ultrafine metal wires for the reinforcing net 3 of the present invention. For comparison, a high carbon steel piano ultrafine wire was obtained by repeating lead patenting and wire drawing four times for a wire having the chemical composition shown in Steel No. 10 in Table 1. The tensile strength of these ultrafine wires was measured, and the metal structure was observed using an ultra-high voltage electron microscope R (3MV).

The results are shown in Table 2. As is clear from this table, the fiber spacing is 90 to 650 people, the cell size is 20 to 90 people, the tensile strength is 330 to 538 kg4/Tsuru2, and the tensile strength is higher than that of the conventional method. It can be seen that this is a significant improvement over the comparative example of 318 kgf/mm2. Furthermore, in this case, as the degree of processing increases, the fiber spacing becomes narrower and the cell size becomes smaller, and the tensile strength improves accordingly.

5% by weight, C: 0.18%, Si: 0.9%,
Mn: 1.5%, S: 0.002%, N: 0.
A wire with a wire diameter of 2.5fi having a chemical composition of 0.002% and A ti :0.003% is reheated and quenched at 900°C, then heated to 800°C, adjusted and cooled to form a ferrite phase and a low-temperature transformation phase. and a composite structure, and the form of the phase produced by low-temperature transformation is mainly acicular, and its volume fraction is 3.
It was set at 5%. This wire was drawn by wet continuous wire drawing to a wire diameter of 10.
An ultrafine wire of 0.50.25 μm was obtained. The characteristics of this polar m-ray were measured, and the metal structure was observed using an ultra-high voltage electron microscope (3MV). For comparison, similar measurements were also performed on piano wire (0.82% C), stainless steel wire (5US304), amorphous wire (Fe-3i-B series), Tanges wire, and aramid wire.

The results are shown in Table 3. As is clear from the same table, the ultrafine metal wire for reinforcing net in the present invention is 300 kgf/la
It has a tensile strength of more than 100% and is rich in toughness. Furthermore, the pole 1ilvA of the present invention has a uniform fibrous structure extending in the drawing direction, the fiber spacing is 100 to 200, and the cell The size ranged from 30 to 90 people.

Furthermore, regarding the ultrafine metal wire for reinforcing net of the present invention, changes in strength after being held in a high-temperature environment, properties of tensile rupture parts and bent parts, fatigue properties, and flexural sage characteristics were also measured.

Figure 3 shows the results of measuring the tensile strength of the 50 μm ultrafine wire shown in Table 3 above after heating it in the air to a temperature between room temperature and 450°C for 30 minutes (curve A). (1
00μmL amorphous wire (50μl11) also shows the results measured under the same conditions (curves B and C),
As is clear from this figure, the ultrafine wire of the present invention has a diameter of 400 mm.
No decrease in strength was observed up to ℃.

Figures 4 and 5 are each 50 μm shown in Table 3 above.
1 is an enlarged view of the bending part. As is clear from Figure 4, the crank fractures after being greatly squeezed (in this case, the fracture contraction ratio is over 50%), and as is clear from Figure 5, the crankshaft remains even after bending (king) deformation. No cracking occurred, and from these points it can be understood that the steel has good toughness.

Figure 6 shows the fatigue properties of the 100μ mist ultra-fine wire shown in Table 1 above in the Hunter fatigue test.The ratio of fatigue limit strength (107 evaluations) to tensile strength (strength ratio) is excellent at 0.38. It shows excellent fatigue resistance. In addition, Fig. 7 shows the ultrafine wire with a wire diameter of 60 μm manufactured under the same conditions.
It shows stress relaxation characteristics when an initial stress of 85% of the tensile strength is applied, and the stress loss is 2% or less. From FIG. 6 and FIG. 7, it is clear that the ultrafine metal wire for reinforcing net of the present invention has high reliability under dynamic and static (repetitive and fluctuating) stress loads.

In addition, in the above example, the matrix resin 2° matrix metal was reinforced with reinforcement @3 composed of stranded wires.
In the present invention, by using a reinforcing net made of ultra-fine metal wires alone, or by combining a plurality of reinforcing fibers and performing sizing treatment, the yarn is made into a woven fabric. May be strengthened by using also netting,! When making IN cloth, only one of the vertical and horizontal lines is made of metal polar IF wire, and the other is made of conventional thin metal wire, such as piano wire, stainless steel am, high manganese a
It is also possible to use titanium wire, etc., and the ultrafine metal wire of the present invention and piano wire, etc. may be twisted to form cotton or woven fabric. , it is possible to combine the advantages of each.

〔Effect of the invention〕

As described above, according to the FRP and FRM of the present invention, as reinforcing fibers, processing cells of 5 to 100 people are arranged in a fibrous shape, and the fiber interval forms an ultrafine grained metal structure of 50 to 1000 people. wire diameter 160 μm or less, tensile strength 300
By using ultra-high strength metal wire with a strength of ~600 kgf/m, the strength of the reinforcing fibers can be much higher than before.
As a result, the strength of FRP and FRM can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an FRP according to an embodiment of the present invention;
Fig. 2 is an enlarged sectional view of the reinforcing net, Figs. 3 to 1O are diagrams for explaining the characteristics of the ultrafine metal wire for the reinforcing net of the present invention, and Fig. 3 shows the strength after being held in a high temperature environment. Figure 4 is an enlarged view of the tensile fracture area, Figure 5 is an enlarged view of the bending part, Figure 6 is a diagram showing fatigue characteristics, Figure 7 is a diagram showing stress relaxation characteristics, Figure 7 is a diagram showing stress relaxation properties, Figure 8 is a characteristic diagram of tensile strength and toughness, and Figures 9 and 10 are micrographs showing the metal m weave of the ultrafine metal wire for reinforcing fibers of the present invention.
1 is FRP, 2 is matrix resin, 3 is reinforcing net, 4.
5 is a twisted wire, and 6 is a metal ultrafine wire. Patent Applicant Kobe Steel Co., Ltd. Representative Patent Attorney Tsutomu Shimoichi Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 1ti7""'
tw)y"'Figure 6Figure 7Stress loading time (hour)Figure 8

Claims (1)

[Claims] (1) Either a monofilament reinforcing fiber, a reinforcing woven fabric made of the reinforcing fibers, or a reinforcing net made of the reinforcing fibers is embedded in the matrix resin or matrix metal. In the fiber-reinforced member, the reinforcing fibers are formed by strongly processing a wire rod by cold wire drawing, and ultrafine cells of 5 to 100 Å produced by the strong processing are arranged in a fibrous shape in one direction, and Ultra-high-strength metal ultrafine wires with a wire diameter of 160 μm or less and a tensile strength of 300 to 600 kgf/mm^2 having a fibrous fine metal structure with an interval of 50 to 1000 Å, a stranded wire made by twisting a plurality of the ultrafine wires, or A fiber-reinforced member characterized in that it is a doubled yarn made by combining a plurality of the ultrafine metal wires and subjecting them to a sizing treatment.