JPS5934227B2 - Manufacturing method of metal fiber for composite reinforcement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing composite reinforcing metal fibers with high strength at high temperatures.

Fiber-reinforced composite materials consist of a base material of fibers and a matrix.The fibers include ceramic fibers containing carbon and boron, metal fibers, resin fibers, etc.The matrix includes resins, metals, ceramics, etc. Various fiber reinforced composite materials can be obtained by combining materials.

Currently, plastic-based composite materials and metal-based composite materials are the mainstream as fiber-reinforced composite materials.

Although glass fibers are generally used for plastic composite materials, the use of metal fibers is also being considered in order to expand their use. On the other hand, the reason why metal-based composite materials have been reconsidered despite their high price is that metal-based materials have superior strength, weather resistance, and heat resistance compared to plastic-based materials; There are various uses such as structural materials, mechanical parts materials, and other materials that require properties different from those of composite materials, and other uses that utilize the above-mentioned properties.

On the other hand, the fibers include ceramic fibers, metal fibers, resin fibers, etc. as mentioned above, among which, among these, those known as metal fibers include tungsten, molybdenum, stainless steel, steel, and helium.

The properties required of these metal fibers include high strength of the fiber itself, high high temperature strength, and low density of the fiber, but in addition to these, the fiber must be easy to manufacture. Needless to say, is important (,
It is particularly important that long fibers can be produced. However, these conventional metal fibers do not necessarily satisfy the above-mentioned properties, and it has been particularly desired to develop fibers that have improved high-temperature strength and can be easily produced into long fibers. The present invention was created in view of the current state of metal fibers described above, and provides a method for producing metal fibers that can easily obtain long fibers with high strength, especially at high temperatures.

That is, the present invention uses titanium 30 at% to 80 at%,
Metal fibers with the remainder being niobium heated at 300°C to 400°C
The strength is further increased by aging treatment in a temperature range of .

Titanium is 30at% to 80at% in niobutetane alloy
% composition is a single solid solution in both the high-temperature and relatively low-temperature areas, so cold workability is extremely excellent in the solid solution state, and area reduction of 99% or more can be easily achieved by cold working. can be obtained.

This property is unique and not found in other high-melting point metal fibers such as tungsten, molybdenum, and beryllium, and as a result, compared to these other metal fibers, the fibers are extremely easy to manufacture. It is what it is. In addition, the most important feature of the present invention is that this alloy is an age hardenable alloy.
Niobium, which is naturally present even when combined with IJx materials
Depending on the usage temperature, due to the age hardening properties of titanium alloys,
In fact, the strength may even be increased, which provides high-temperature strength that cannot be obtained with conventional metal fibers.

The metal fiber obtained according to the present invention has excellent corrosion resistance and chemical resistance, and is not affected by anything other than fluoronitric acid and has excellent weather resistance. In addition, the coefficient of thermal expansion is approximately twice that of tungsten and molybdenum, and is close to that of copper or aluminum as a matrix, so when combined with this, the adhesion between the IJx and fibers is good. . Furthermore, since the density of this metal fiber is lower than that of tungsten, it has many advantages such as superior specific strength. However, in the present invention, the composition of the metal fiber is changed from 30 at% to 80 at%.
%, the remainder is less than 30at% or 80a
This is because if it exceeds t%, cold workability deteriorates and the effect of aging treatment is not apparent.

Further, the aging temperature is set to 300° C. to 400° C. because the desired strength cannot be obtained by age hardening outside this temperature range. Next, embodiments of the present invention will be described.

Example 1 Three types of niobium-titanium alloys were prepared by vacuum arc melting, including 35 at% tetanium remaining niobium, 66 at% tethane remaining niobium, and 78 at% titanium remaining niobium, and each of these was hot worked to a diameter of 8 mm. It was made into a stick.

This was heated at 850°C to form a solution, and then water quenched. This has an inner diameter of 8.2. φ, outer diameter 9, 5wI. It was inserted into a 7nφ copper pipe and cold-worked into a 3-strength wire using a groove roll. Bundle 50 more of these to create an inner diameter of 25mφ and an outer diameter of 301rL.
Insert it into an Inφ copper tube and use a groove roll and wire drawing machine to make it 0.
It was cold worked to 3uφ. This was annealed at 300°C for 72 hours and then further annealed at 380°C for 2 hours for aging treatment. A sample with a length of 3007IIs was taken from each of the as-processed wire rod and the aged wire rod, and the copper on the surface between the gauge points was removed with nitric acid to form 50 niobium-titanium alloy fibers with an outer diameter of about 23μ. A tensile test was conducted.
Table 1 shows the characteristics of typical conventional metal fibers for comparison with this result. As is clear from the table, the yield strength and tensile strength of the niobium-titanium alloy fiber obtained by the present invention are comparable to conventional stainless steel and molybdenum, but the specific tensile strength, which is calculated by dividing the tensile strength by the density, is ,
They are superior to conventional metal fibers such as stainless steel, tungsten, and molybdenum, and have the advantage that when composited with a dense matrix such as copper, the total weight can be reduced for the same strength.

Example 2 The niobium 78 at% titanium alloy fiber of Example 1 was composited into copper at a volume ratio of 0.1, 0.2, 0.3, 0.4, and 0.5%, and this was 0.41 due to cold working
The tensile strength at room temperature was determined for a wire of njnφ, annealed at 300°C for 72 hours, and further annealed at 380°C for 2 hours, and a copper composite as cold worked.

This result and the tensile strength of a copper composite reinforced with continuous fibers of tungsten and molybdenum are shown in FIG. 1 as a comparative example. As is clear from the figure, the tensile strength of the copper composite using metal fibers obtained by the present invention at room temperature is almost the same as that using tungsten fibers, and that of the copper composites using the tungsten fibers after aging treatment. It is slightly stronger than the one using . Therefore, if we compare the specific strength, it can be seen that a composite material that is sufficiently stronger than tungsten or molybdenum can be obtained. Example 3 The niobium 78 at% titanium alloy fiber of Example 1 was composited into aluminum to a volume ratio of 50%, and this was cold-worked to reduce the
．． 5wφ wire annealed at 300°C for 72 hours and then at 380°C for 2 hours, and as cold-worked aluminum composites at 200°C and 400°C.
The high temperature tensile strength at each temperature of , 600°C was measured.

As a comparative example, this result and the high-temperature tensile strength of a composite reinforcement material of boron, molybdenum, and beryllium metal fibers and aluminum are shown in FIG. As is clear from the figure, it can be seen that the aluminum composite reinforced with niobium-titanium alloy fibers exhibits extremely stable strength customization even at high temperature parts.

Particularly, the decrease in strength in the high temperature region is small because the &L niobium-titanium alloy fiber has age hardening properties.

In Examples 2 and 3, the case of niobium 78 at% titanium was described, but due to the nature of age-hardenable alloys, if the composition of the metal fiber of the present invention is within the range, aging treatment temperature and time can be appropriately selected depending on the composition. , strength at room temperature, and strength at high temperature can be adjusted appropriately.

For example, in Examples 2 and 3, the cold-worked wire was annealed at 360°C for 50 hours. It can be somewhere between aged and as-processed. As described above, the present invention's niobutetane alloy fiber (I. It has age-hardening properties not found in other fibers, and therefore has high strength at high temperatures.It has a wide range of uses as a metal fiber for reinforcing composite materials, regardless of whether it is plastic or metal, and its practical value is extremely high. .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the tensile strength at room temperature of a composite reinforcement material using metal fibers of the present invention and a composite reinforcement material using conventional metal fibers.

Claims (1)

[Claims] 1. A method for producing a composite reinforcing metal fiber, which comprises aging a metal fiber consisting of 30 at% titanium to 80 at% titanium and the remainder niobium in a temperature range of 300°C to 400°C.