JPS5811500B2 - Amorphous metal alloy with high crystallization temperature and high hardness value - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides amorphous metal alloy compositions, particularly those containing a substantial amount of the element Mo.
, T, Ta and Nb, which exhibit both high crystallization temperatures and high hardness values.

Research has shown that it is possible to obtain solid amorphous metals for certain alloy compositions, and the term "amorphous" herein means "solid amorphous". .

Amorphous materials are generally characterized as non-crystalline or glassy materials, ie, the materials have virtually no long-range order.

Generally, it is appropriate to use X-ray diffraction measurements to distinguish between amorphous and crystalline substances.

Additionally, transmission electron microscopy and electron diffraction can be used to distinguish between amorphous and crystalline states.

In X-ray diffraction images of amorphous metals, the intensity changes gradually with the diffraction angle.

Such an image is qualitatively similar to the diffraction image of a liquid or an ordinary window glass.

On the other hand, in crystalline metals, the intensity of the diffraction pattern changes rapidly with the diffraction angle.

These amorphous metals are in a metastable state.

When heated to a sufficiently high temperature, it crystallizes with the generation of heat of crystallization, and the diffraction pattern changes from having a glassy or amorphous character to having a crystalline character.

It is possible to create metals that are two-phase mixtures of amorphous and crystalline states, the relative proportions of which can vary from entirely crystalline to entirely amorphous.

Amorphous metal, as used herein, refers to a metal that is primarily amorphous, ie, at least 50% amorphous, but may have a small portion of material present as intercalated crystallites.

For appropriate compositions, appropriate processing will yield the metal in an amorphous state.

One typical operation involves contacting the molten alloy with a solid metal substrate, such as copper or aluminum, and spreading it out so that the heat of the molten metal is rapidly lost to the substrate.

106°C when the alloy is expanded to a thickness of about 0.002 inches
A cooling rate on the order of 1/sec can be achieved.

See, e.g., R. C. Rule (Materials Science and Engineering, Vol. 1, pp. 313-319, 1967), discussing the dependence of cooling rate on molten metal processing conditions. .

For alloys of appropriate composition and for sufficiently high cooling rates, such processing yields amorphous metals.

Any method that provides a suitably high cooling rate can be used.

Illustrative examples of operations that can be used to create amorphous metals include H,
S. Chan and C.E. Miller (Review of Scientific Instruments, 1237-123)
8 pages, 1970), R. Pond Jr. and R. Madein (Transactions of the Metal Society, A.I.)
ME, Volume 245, Pages 2475-2476, 196
There is a circuit cylindrical method as written by 9th grade).

Amorphous alloys containing substantial amounts of one or more of the elements Fe, Ni, Co, V and Cr are H, S, Chan, C, E,
Miller, U.S. Patent Application No. 31, dated December 26, 1972
No. 8146.

Such alloys are useful for a variety of applications.

However, such alloys are characterized by a crystallization temperature of about 425 DEG to 550 DEG C. and a hardness of about 600 to 750 DPH (diamond pyramid hardness).

According to the invention, an amorphous alloy is described which has high thermal stability with crystallization temperatures in the range of about 650 DEG to 975 DEG C. and high hardness with values in the range of about 800 to 1400 DPH.

Those having the following general composition have these properties and are called metal-metalloid systems and can be represented by the general formula RrM8Xt.

Here, R is at least one of the elements molybdenum, tungsten, tantalum, and niobium, M is at least one of the elements nickel, chromium, iron, vanadine, aluminum, and cobalt, and X is the element phosphorus, boron. , carbon and silicon, and r is about 40 to 60 atom%
S is in the range of about 20 to 40 atom % and t
is in the range of about 15 to 25 atomic percent.

The preferred composition is about 45 to 55 atomic % r and about 25 to 55 atomic % S.
35 atom %, and t is in the range of about 18 to 22 atom %.

The crystallization temperature of the metal-metalloid composition is about 800° to 975°
℃ range, and the hardness is in the range of about 1000 to 1400 DPH.

Such metallic glasses, whether metal-metalloid or metal-metal, are particularly useful in heat-resistant applications at high temperatures (approximately 500° to 600°C).

Possible applications include the use of these materials as electrodes in high temperature electrolyzers and as soluted fibers in composite construction materials.

A. Metal-Metalloid Compositions Most liquid-quenched glassy compositions of the various metal-metalloid systems exhibited crystallization temperatures of about 425° to 550°C.

According to the invention, the composition represented by the general formula RrM8Xt has a crystallization temperature in the range of about 800° to 975°C.

In the formula, R is at least one of refractory metals Mo1W, Ta, and Nb, and M is metal Ni, Cr1Fe1V, AI, and C.

(is also one, and X is a metalloid P, B, C.

At least one of Si.

The purity of all metals listed above are those found in normal commercial practice.

For Mo-based compositions, there are few amorphous alloys (approximately 2
Found in systems containing 5 at.% Ni5Cr, Fe, V or AI.

Typical composition is Mo52CrlOFelONi in atomic %
3P12B8 and Mo40Cr25Fe15B8C7S
It is i5.

Such amorphous alloys, that is, glasses, are subjected to differential thermal analysis (DTA).
) Retains high thermal stability as demonstrated by testing.

The temperature Tc for maximum crystallization is determined by whether excessive heat is generated at a special temperature (crystallization temperature) by gently heating the glass sample, or whether excessive heat is generated when the glass sample exceeds a special temperature range (glass transition temperature). It can be accurately determined from DTA by noting whether or not it is absorbed.

Generally speaking, the less well defined glass transition temperature is approximately 50° below the lowest or first crystallization peak Tel.
It encompasses a temperature range above which, as is customary, the viscosity is in the range of about 10 13 to 10 14 poise.

Approximately 25 to 32 at.% of Ni, Cr, Fe, Al (either singly or in combination), plus approximately 12 at.% of P, and approximately 8 at.% of B.
Various MO-based glasses with a temperature of about 800° to 900°C
crystallizes in the range of

When P is replaced with C or Si is replaced with C up to 8 atomic %, T.

increases by about 40° to 50°C. Further thermal stability is achieved by partially replacing Mo with W.

Alloys containing about 8 to 20 atomic percent W are about 900 to 950°C
It has a crystallization temperature in the range of .

High Tg glass-forming compositions also exist in W-based alloys.

Typically these alloys contain about 15 to 25 atomic percent MO,
It contains about 25 atom % Fe1Ni and Cr1 and about 20 atom % P, B, C and Si.

These alloy glasses are extremely stable and crystallize at temperatures above 950°.

For example, one glass composition W4oMo15Cr15Fe5Nt5P6B6C5Si
13 shows two crystallization vertices 960° and 9 in DTA tracking.
Indicates 80°C.

However, as the Mo content increases to 40 atom %, it becomes increasingly difficult to form a glass.

Glass melts about 105~b It is formed by cooling the mixture.

A variety of methods are available, as known in the art, for producing flat plate quenched foils, quenched connecting ribbons, wires, etc. 9 Glasses exhibiting high Tg properties such as those described above also have high Tg properties. It exhibits higher ductility and higher corrosion resistance than crystalline or partially crystalline samples.

Moreover, these amorphous alloys have fairly high hardness values.

Typically, the hardness for Mo- and W-based glasses ranges from about 1000 to 1400 DPH.

This is comparable to amorphous alloys of metal-metalloid composition containing substantial Fe or Fe-Ni but no substantial amount of refractory metal.

For these latter alloys, hardness is typically 600-75
It is 0DPH.

Figure 1 shows the ternary composition diagram of the R-M-X system.
Here R is Mo1W, Ta and/or Mb, M is Ni1
Cr, Fe1V, AI and/or Co, X is P, ,B,
C and/or Si.

The polygonal area designated a-b-c-d-e-fa surrounds the glass-forming area, which also includes compositions with high Tg and high hardness.

Outside this composition range either no substantial degree of formability is obtained or the advantageous properties are unacceptably reduced.

The composition boundaries of this polygonal area are described as follows: r is in the range of about 40-60 atomic percent, S is about 20-4
0 atomic % range, and t is in the range of about 15 to 25 atomic %.

It is formed with a composition expressed by the maximum value of Tg and hardness & field gh, where r is about 45 to 55 at%, S is about 25 to 35 at%, and t is about 18 to 22 at% (with and specifically t is in the range of about 20 atomic %).

Therefore, the latter composition range is preferable.

The maximum benefit is when R is Mo and/or W and M is Ni.

Obtained for compositions that are Fe and/or Cr.

Example 8: Air arc for melting and liquid quenching of metal-metallic compositions and high-temperature reactive alloys.
A flat plate device was used.

This equipment is a conventional electric arc melting button furnace modified to perform "mar-and-anvil" plate quenching of alloys in an inert atmosphere, coupled to a 4-inch diffusion pump system. Includes stainless steel base.

Quenching is accomplished by equipping the chamber with a planar water-cooled copper hearth on the floor and an air-driven copper ingot hammer positioned over the molten metal.

Conventionally, arc melting is accomplished by negatively biasing a tungsten-tipped copper shaft inserted through the top of the chamber and positively biasing the bottom of the chamber.

The P-containing alloy was made by sintering the powder components and then homogenizing them by electric arc melting.

All other alloys were made directly by repeated electric arc melting of the constituent elements.

A single alloy button (approximately 200 mg) was remelted and then melted to a thickness of approximately 0.00 mm with a hammer placed directly above the molten pool.
"Shock-quenched" into 4 inch foil.

The cooling rate obtained with this method is about 105~b The foil was tested for achromatic saturation by X-ray diffraction and DTA.

The shock-quenched foil directly under the hammer may undergo plastic deformation after solidification.

However, some of the foils formed from the melt that protruded from the thermometer were undeformed and were therefore suitable for hardness and other related tests.

The hardness was measured by the diamond pyramid method using a Vickers type indenter made of pyramidal diamond with a square bottom including an angle of 136° between opposing surfaces.

Crystallization temperatures and hardness values for various metal-metalloid compositions are shown in Table 1.

[Brief explanation of drawings]

Figure 1 is a ternary composition diagram expressed in atomic % of the metal-metalloid system R-M-X, where R is one or more of the elements Mo, W, Ta, and Tb, and M is the element Ni1CrsFesVsA.
1 or more of Co, X is the element P, B, C, S
i is 1 or more.

Claims (1)

[Claims] 1 formula % formula % (wherein R is at least one element selected from the group consisting of molybdenum, tungsten and niobium, and M is selected from the group consisting of nickel, chromium, iron and aluminum) (both are one element; %, t is 15 to 25 atomic %, and the sum of r, S, and t is 100), and has a crystallization temperature within the range of 800 ° C to 975 ° C. Amorphous metal alloy at least 50% amorphous, with high crystallization temperature and high hardness, characterized in that it has a hardness in the range of 1000-1400 DPH (diamond pyramid hardness).