JPS5933657B2 - Manufacturing method of Cu-W fiber composite material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a CuW fiber composite material, and in particular to a method for producing a CuW fiber composite material.
The present invention relates to a method suitable for fiber composite materials in which fibers are arranged in the same direction.

Fiber composite materials combine metals and fibers with different properties to compensate for the drawbacks of conventional single materials, or to obtain new properties by combining them.

Many composite materials have been developed so far, but among them, the combination of Cu and W fibers is a material that is relatively easy to produce because it has good wettability, little chemical reaction, and a large difference in elastic modulus. It is said that

However, it has not yet been fully put into practical use because its manufacturing methods are complicated, its workability is poor, and mass production is difficult.

Recently, a few methods have been developed to commercialize Cu W fiber composites.

All of these improve practicality by making it possible to plastically process composite materials.

However, in these methods, the annealing temperature of the composite material applied during plastic working ranges from the transition temperature of W (around 200°C) to just above the primary recrystallization temperature of Cu (300 to 350°C).
°C), the processing strain of the Cu matrix remains, or the adhesion between the Cu and W interfaces does not recover, resulting in cracks occurring in the initial processing (processing degree of 14-17%), which inevitably results in processing failure. The number of annealing operations increased, resulting in poor work efficiency.

On the other hand, plastically processed composites were unable to obtain sufficient properties due to weak interfacial adhesion.

An object of the present invention is to provide a highly productive manufacturing method for the combination of Cu and W fiber, which is inferior in ductility to Cu and has a high modulus of elasticity.

For plastic working of a fiber composite material that combines a highly ductile Cu matrix and a high modulus W fiber, it has been desired to process the W fibers while freely moving them along with the plastic flow of the Cu matrix.

This was also necessary to prevent the W fibers from breaking due to plastic working.

However, for this purpose, as described in the prior art, it is necessary to completely remove the processing strain of the Cu mud IJ which occurs during plastic working, and to restore the adhesive force between the Cu and W interfaces.

The present inventors believe that these temperatures are higher than the second recrystallization temperature of Cu (7
It has been found that this problem can be solved by coarsening the crystal grains of the Cu matrix through annealing treatment at a temperature of 50 to 950°C.

This annealing is an unreasonable treatment considering the plastic processing conditions for general materials.

This is because, even when considering mechanical properties, it is clear that as the crystal grains become coarser, the strength and area of area decrease rapidly, and the toughness is lost.

However, the above general theory does not apply to Cu-W fiber composite materials.

In other words, in Cu W-fiber composite materials, W fibers exist as a mixture in the Cu matrix, so even if you try to coarsen the grain size, the growth will be hindered by the W fibers, preventing the formation of coarse grains. thwarted.

Furthermore, since internal strain remains in the Cu matrix due to the difference in thermal expansion between the W fibers and the Cu matrix, there is no decrease in toughness.

On the other hand, the adhesive strength of the Cu-W interface is also restored by high-temperature annealing treatment.

The ability to plastically process a Cu-W fiber composite material with large differences in elastic modulus and ductility without causing the free movement of the fibers and a decrease in the adhesive strength at the interface is a breakthrough. It promises a wide range of applications due to its low cost and improved properties.

Example 1 W fibers with a diameter of 0.1φ and oxygen-free copper fibers are twisted together, and the length is 5.
Cut it into a mold and mold it with a molding pressure of 51 tyn/(i,
A composite W skeleton with a length of 40 mm, a width of 30 mm, and a thickness of 3 mm was produced.

and heating temperature 9 in a vacuum of 2-5 x 10-'imHg.
Degassing treatment was performed by holding at 00°C for 1 hour.

On the other hand, in a vacuum of 2~5X10'mmHg, 13
The degassed composite W skeleton is gradually lowered into the molten metal by heating to 00°C to 1350°C, and argon gas is filled into the vacuum chamber to reduce the pressure in the chamber to 1.
It was taken as atmospheric pressure.

After the molten oxygen-free copper permeated the entire composite W skeleton, it was cooled.

The thus produced non-oriented Cu-33%w fiber composite material was rolled at intermediate annealing temperatures of 300°C and 900°C to produce a 0.3t thin plate material.

As a result, when the annealing temperature was 300°C, intermediate annealing was required at a rolling degree of 14 to 17, and intermediate annealing was required 6 to 7 times to produce a 0.3 t thin plate. .

On the other hand, in the case of 900°C annealing, the rolling degree is 34 to 4.
Intermediate annealing was performed at 0%, and the number of annealing was 3 times.

It can thus be seen that annealing at 900°C reduces the rolling process to about 1/2 or less compared to the conventional annealing temperature of 300°C.

Figure 1 shows 0,31 which was rolled at an annealing temperature of 900℃.
An X-ray transmission photograph of the Cu-33 volume % w composite material is shown.

As can be seen from this figure, the W fibers are isotropically dispersed.

Example 2 0.3t Cu-33 produced by the same method as Example 1
The volume%w fiber composite material was heated at 300°C as it was rolled.
The mechanical properties were investigated when annealed at 600°C and 900°C.

Figure 2 shows the relationship between annealing temperature and mechanical properties.

As can be seen from this figure, the as-processed strength is high due to the processing strain of the Cu matrix, but the elongation is 1
This is a significantly smaller value.

The strength after annealing at 300° C. and 600° C. decreases rapidly because the processing strain of the Cu matrix is removed, and on the other hand, the elongation shows a larger value than that of the as-processed material.

The mechanical properties after annealing at 900°C are significantly increased in both strength and elongation compared to materials annealed at 300°C or 600°C.

Example 3 0,31 thin plate Cu-50 produced by the method of Example 1
The coefficient of thermal expansion was measured for the volume $w fiber composite material in the temperature range from 40°C to 300°C.

As a result, the composite material subjected to intermediate reannealing at 300°C was 7
．． It exhibits a thermal expansion coefficient of 0~7.5X10'/℃, and the 900℃ intermediate annealing material has a coefficient of thermal expansion of 6.4~6.7X10-
It showed a significantly small coefficient of thermal expansion of 6/°C.

As is clear from the above examples, the Cu W fiber composite material has excellent properties such as high strength, low coefficient of thermal expansion, and high electrical conductivity.

The present invention facilitates plastic processing of fiber composite materials,
The improved productivity is extremely effective in increasing the practical use of Cu-W fiber composite materials.

Note that the thin plate material of the fiber composite material obtained by the method of the present invention is
Since the adhesive strength at the interface between Cu and W is high, punching is easy and, therefore, it is possible to produce thin plate materials with complex shapes.

[Brief explanation of the drawing]

Figure 1 is an X-ray radiograph of isotropic Cu-33 volume%w fiber composite material, Figure 2 is the annealing temperature of isotropic Cu-33 volume%w fiber composite material and machine after annealing treatment. FIG.

Claims (1)

[Claims] I A method of processing a composite material containing W fiber in a Cu matrix by repeating annealing treatment and plastic working, wherein the annealing temperature is set to be equal to or higher than the secondary recrystallization temperature of the Cu matrix. Cu W, which is characterized by
Method for manufacturing fiber composite materials. 2. The method for producing a Cu-W-fiber composite material according to claim 1, wherein the W-fibers are arranged non-directionally in a Cu matrix.