JPS601374B2 - Method for producing amorphous alloy with excellent strength and corrosion resistance - Google Patents

Description

[Detailed Description of the Invention] Recently, fiber-reinforced or laminated composite materials have been progressing,
There is a strong demand for metal fibers and foils to be of high quality and inexpensive.

Metals are generally excellent materials in terms of strength and toughness, but forming them into fibers or foils requires many steps and requires a large amount of manufacturing cost.

For example, metal whisker crystals are ideal fiber materials with high strength, but they are expensive because they are produced through chemical reactions and phase changes such as precipitation from solutions, reduction, and vapor condensation.
It is also difficult to mass produce. Furthermore, thin metal wires such as piano wires are extremely expensive because they require repeated cold drawing and intermediate drawing processes. The same applies to metal foil. Therefore, methods of directly producing metal fibers and metal foils from molten metal have been studied as an inexpensive means of producing these materials.

However, metal fibers and foils produced by conventional methods are extremely insufficient in terms of strength and spreadability. However, recently it has become apparent that iron or nickel contains over 10% phosphorus and several%
A material with excellent strength and axial elongation can be obtained by spraying carbon or an alloy containing several percent of chromium from a molten state onto a metal conductor with good thermal conductivity, rapidly solidifying it, and making it amorphous. It was found that However, obtaining such an amorphous state depends to a large extent on the component system and cooling conditions, and hitherto published component systems were empirically limited to the above range. Therefore, the present inventors conducted extensive research on the component system and manufacturing conditions to obtain an amorphous state, and first determined that the basic components were
It has been found that it is sufficient to add two or more metalloid elements based on one of the group transition elements iron, cobalt, and nickel, or a mixture thereof. The amorphous metal thus obtained has significantly superior strength and ductility compared to conventional crystalline rapidly solidified metals. However, further increasing the strength of these materials is extremely effective in expanding the range of applications.

Therefore, the present inventors investigated the effects of various alloy additions based on the above-mentioned basic components, and found that vanadium, niobium, and tantalum, elements of the chord group of the weekly table, are effective for this purpose. It is well known that these Group G elements serve as catalysts for the reductive decomposition reaction of nitrogen oxides, but when they are made amorphous as in the present invention, they are In comparison, it is expected that the amorphous alloy of the present invention will be highly reactive due to its large number of structural defects.Therefore, the amorphous alloy of the present invention is expected to be used not only to utilize its strength but also as a catalyst. That is, this is the object of the present invention. According to the findings of the present inventor, the amount of the group 8 element to be added should be determined from the viewpoint of making the entire alloy amorphous, and for this purpose, the melting point of the entire alloy must be set to It is effective to keep the temperature within +150° C. of the highest temperature of the eutectic temperature of the binary alloy of any of the elements and any of the added metalloid elements.

Further, regarding the cooling conditions, it is necessary to rapidly cool the alloy from a molten state to 30,000°C at a rate of 1°C or more per second. In this case, an amorphous structure refers to a state in which diffraction lines characteristic of metal crystals are not observed in ordinary X-ray diffraction. In addition, metalloid elements refer to boron, carbon, poppy, element, and phosphorus. In the present invention, the group 8 transition elements forming the matrix of the alloy include iron,
Although the three elements of cobalt and nickel were targeted, the other eight elements
It is easy to imagine that group elements could also have the same effect. It goes without saying that there is no problem even if unavoidable impurities are included as ingredients. The theoretical basis on which the combination of the above components makes it easy to create an amorphous metal alloy and has high strength is currently unclear.

However, the present invention was obtained as a result of systematic experiments on the relationship between the tendency to form an amorphous structure, the type of additive element, and the cooling rate. That is, the research conducted by the present inventors has revealed the regularity of the types of added elements on the weekly table. One of the key points of the present invention is to ensure an amorphous state by combining a Group 8 transition element and a metalloid element, and to add a chord group element to improve the properties. Conventional iron,
Amorphous metals based on nickel or palladium have been announced, but as a result of a series of studies in which the base iron was replaced with a metal element, the present inventors found that not only nickel but also cobalt can be used to replace the base metal. Although a crystalline metal can be obtained, it has been found that substitution with manganese and copper, which are outside of Group 8, makes it difficult to become amorphous. On the other hand, as elements to be combined with these base components, it has conventionally been known to simultaneously add more than ten percent of phosphorus and a few percent of carbon.

However, the present inventors have conducted extensive research on these, and have discovered phosphorus and boron, phosphorus and poppy, element, boron, poppy, element, and semi-semi-combinations such as boron, carbon, poppy, and element. It was found that a combination of metals is effective, and furthermore, it was found that an amorphous state can be maintained even if an element from Group 1 of the periodic table is added up to a certain limit. Regarding the amounts of these additives, conventional research has limited the total amount of additive elements other than iron or nickel to about 20 atomic percent, and no regular guideline for component design has been obtained.

As a result of extensive experiments, the inventors of the present invention have determined that the melting point of the alloy is one of the criteria, and that it is the eutectic of the 29 alloy between the base group 8 element and any of the metalloid elements added. This clarifies that it is determined by the relationship with temperature. In other words, as mentioned earlier, it is necessary to lower the melting point of the alloy to a certain level, and this is achieved by creating a eutectic binary alloy of one of the base iron, cobalt, or nickel and one of the metalloid elements added. It is better to have a temperature of 15,000 or less than the highest temperature.
It has been found that it is effective to adjust the ingredients so that the concentration is 0CO or less. Of course, even if the alloy components are adjusted in this way, it is impossible to obtain an amorphous metal depending on the cooling rate, and it is necessary to solidify and cool the metal from a molten state sufficiently quickly.

The first area where rapid cooling is required is during solidification, but if the material is kept at a high temperature for a long time after solidification, it will crystallize due to atomic diffusion, so it is necessary to maintain a sufficient cooling rate even after solidification. Strictly speaking, it is conceivable that the required cooling rates are different during solidification and after solidification, but it is difficult to actually control them separately. Based on experiments with various cooling rates and theoretical predictions, the present inventors have determined that the cooling rate is approximately 300°C, at which point crystallization stops. It has been found that it is necessary to cool the material including the ground group element at a speed of 0/sec or more.

The amorphous alloy obtained in this way has superior strength and malleability compared to ordinary crystalline rapidly solidified alloys, and can be used for wire ropes, steel cords, etc.
Applications include filters, fiber-reinforced composite materials, concrete reinforcement materials, meshes, sound and earthquake insulation materials, and even as a catalyst for the removal of nitrogen oxides.

The present invention is extremely significant in that it has discovered a law in designing amorphous alloys that has departed from the limited experience of the prior art. Example iron, 11 at% phosphorus, 10 at% borosilicate, 2 vanadium
The melting point of the alloy to which 0 atomic % is added is 1,180 pm, which is lower than the higher of the eutectic temperatures of the two elements iron and phosphorus, iron and silicon, which is 120,000 for the iron-silicon system (see Figure 2).

A sample of this alloy rapidly cooled from the molten state at a cooling rate of 1 x 1 p℃/sec becomes an amorphous state with a tensile strength of 280k.
9/Boiled iron - 13 at% phosphorus - 10 at% silicon 20
After 0k9', it was much higher than that and did not break even when bent 180 degrees. In addition, an alloy with the following composition is prepared from a molten state.

The material rapidly solidified at a cooling rate of ○ seconds exhibited an amorphous state, and its properties were as follows. Furthermore, the corrosion resistance was also good.

[Brief explanation of the drawing]

Figure 1 shows iron-11 atomic% P- produced by the method of the present invention.
This is an X-ray diffraction photograph of a 10 atomic % Si-20 atomic % V amorphous alloy, showing an amorphous state. FIG. 2 is a phase diagram of an iron-silicon binary alloy. The melting point of the iron-11 atom% phosphorus-10 atom% silicon-20 atom% vanadium alloy is 1180 qo, which is the eutectic temperature of the binary system of iron and silicon.
Indicates that the temperature is within 1350 points (shaded area) which is 15020 degrees higher than 200°C. Younger brother - Kyota Z diagram

Claims (1)

[Claims] 1 One or more of iron, cobalt, and nickel as basic components, two or more of boron, phosphorus, and silicon as semimetallic elements, and one or more of vanadium, niobium, and tantalum, and an alloy thereof. It is contained so that the melting point is within +150°C from the highest temperature of the eutectic temperature of the binary system of the basic components constituting the alloy and any of the above-mentioned metalloid elements, and 30°C from the molten state
A method for producing an amorphous alloy with excellent strength and corrosion resistance, characterized by rapidly solidifying the alloy at a cooling rate of 5° C./sec or more in a temperature range of 0° C.