CN106868430A - A kind of alloy component design method of regulation and control aluminium-based amorphous alloy Forming ability - Google Patents

Abstract

The invention discloses an alloy composition design method for regulating the formation ability of aluminum-based amorphous, and belongs to the technical field of aluminum-based amorphous alloys. The method is based on the electronic interaction mechanism of trace addition of TM and RE elements in the Al-TM (transition group elements)-RE (rare earth elements) ternary amorphous alloy system, formulating formula (1) as δ=|K _P- 2K _F |, in the formula (1): when the δ value approaches 0, the total energy of the system tends to be the lowest, and the amorphous formation ability is enhanced; according to this rule, the amorphous formation ability of the system is regulated to prepare large The proposed method solves the problem of a large amount of waste of resources in the composition design of aluminum-based amorphous alloys in the past, and designs the largest-sized five-element complete bulk aluminum amorphous alloy in the world. The invention plays an important role in promoting the expansion of the application range of the light-weight and high-strength aluminum-based amorphous alloy.

Description

An Alloy Composition Design Method for Controlling Aluminum-Based Amorphous Formation Ability

technical field

The invention relates to the technical field of aluminum-based amorphous alloys, in particular to an alloy composition design method for regulating the formation ability of aluminum-based amorphous.

Background technique

At present, the development of lightweight materials plays an important role in promoting energy conservation and improving the efficiency of various equipment. Therefore, it has become the focus of research and development in various fields such as automobiles, aircraft, ships, and weaponry. For example, in recent years, the application proportion of various lightweight materials in weapon models has shown a rapid upward trend. Among them, aluminum alloys, especially high-strength aluminum alloys, are widely used in various fields of national economic construction and national defense construction due to their advantages of light weight, high specific strength, and high specific stiffness, and are widely used in the aviation industry. Compared with traditional aluminum alloys, amorphous aluminum alloys have high specific strength, good toughness and excellent corrosion resistance, and their tensile strength can exceed 1000MPa, which has exceeded the current level of high-strength steel. Comparable to, and maintain good plasticity and high temperature stability. Its appearance provides a new way for the development of lightweight ultra-high-strength metal structural materials. However, the main factor limiting the application of this type of material is the poor glass-forming ability of Al-based amorphous alloys. The maximum amorphous critical size obtained so far is 1mm, which still cannot meet the needs of practical engineering applications. Therefore, improving the forming ability of aluminum-based amorphous alloys is the primary factor to expand their application range.

In order to determine the Al-based alloy composition with the best amorphous-forming ability, the structural nature that affects the Al-based amorphous-forming ability needs to be analyzed. Among them, the atomic structure of Al-based metallic glasses plays an important decisive role in its amorphous formation ability. The Efficient Cluster Packing (ECP) model and the quasi-equivalent cluster close-packing model reveal that the three The structural nature of the amorphous-forming ability of metasystems. However, based on the hard sphere assumption, the clusters centered on RE(TM) atoms share Al atoms and fill the entire space in an fcc manner. However, this ordered crystal structure does not exist in disordered metallic glasses, and the influence of chemical effects on the stability of metallic glasses is not considered. Therefore, when the model is used to predict the Al-TM-RE ternary system, there is a deviation of about 4.6-19.8 at.% between the experimental value and the predicted value. It is worth noting that microalloying plays a crucial role in the development and design of Al-based metallic glass alloy systems, for example: on the basis of Al ₈₆ Ni ₈ Y ₆ alloy, only 2 at.% Co and La replace Ni and Y can double the amorphous forming ability, and finally successfully obtained an Al-based bulk metallic glass rod with a diameter of 1mm; adding 0.5 at.% Ti or V to the Al ₈₈ Y ₇ Fe ₅ alloy can significantly improve its amorphous-forming ability. The microalloying effect can increase the stability of the liquid phase and inhibit the formation of the crystalline phase, thereby enhancing the amorphous-forming ability. However, the structural origin of the effect of microalloying on the formation ability of quaternary and quinary Al-based amorphous remains unclear. Previous attempts to reveal the structural origin of the influence of microalloying on the ability of Al-based amorphous formation from the perspective of atomic structure, for example: using X-ray absorption spectroscopy to study the addition of La and Co elements to Al ₈₆ Ni ₈ Y ₆ alloys, using extended X The ray absorption fine structure method was used to study the addition of La and Hf elements to Al ₈₈ Y ₇ Fe ₅ alloys, but the research results all showed that there was no difference in the atomic structure of Al-based amorphous alloys before and after microalloying.

According to the principle of electronic structure of metallic glass, there is a strong electron orbital hybridization effect in the Al-based metallic glass system, which has an important impact on the structure, but conventional methods cannot analyze this result, so it is necessary to deeply understand the electronic properties of aluminum-based amorphous alloys. The mechanism of the structure level on the ability of amorphous formation, in order to seek a composition design method suitable for aluminum-based amorphous alloys.

Contents of the invention

The purpose of the present invention is to provide an alloy composition design method for improving the formation ability of aluminum-based amorphous alloys, which solves the problem of complex composition design of aluminum-based amorphous alloys in the past, and designs a completely amorphous alloy with a critical size of 1.5mm, which is At present, the largest aluminum-based bulk amorphous alloy prepared in the world has expanded the application range of lightweight and high-strength aluminum-based amorphous alloys as structural materials.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

An alloy composition design method for regulating the formation ability of aluminum-based amorphous. The method is based on the electronic interaction mechanism of micro-addition of TM and RE elements in the Al-TM-RE ternary amorphous alloy system, and formula (1), The law presented in the formula (1) is: when the δ value approaches 0, the total energy of the system tends to be the lowest, and the amorphous formation ability is enhanced; according to the law in the formula (1), the Al-TM-RE three Control the amorphous formation ability of the primary amorphous alloy system to prepare large-sized aluminum-based amorphous alloys;

δ＝|K _P -2K _F | (1);

In the formula (1): 2K _F is the diameter of the Fermi surface, and the calculation method of 2K _F is as in formula (2); K _P is the diameter of the pseudo-Brillouin zone, and the calculation method of K _P is as in formula (3);

In formula (2), Z _FEM is the number of electrons contributed by free electrons, Z _hyb is the number of electrons contributed by electron hybridization effect, n ₀ is the atomic number density;

In formula (3), λ is the wavelength of X-rays, and θ is the diffraction angle corresponding to the main diffuse peak in the X-ray diffraction spectrum.

In the Al-TM-RE ternary amorphous alloy system: TM is a transition group element, and RE is a rare earth element.

In the Al-TM-RE alloy system, by adding a small amount of Co or La elements, when δ=0.009, the amorphous formation ability of the quaternary aluminum-based amorphous alloy is the best, and the critical size of 1mm (diameter) can be prepared. Aluminum based amorphous alloy rods. In terms of atomic percentage, the alloy composition of the aluminum-based amorphous alloy rod with a critical dimension of 1 mm (diameter) is: Al 86%, Ni 6.75%, Co 2.25%, Y 5%; or, the The alloy composition of the aluminum base amorphous alloy rod with a critical dimension of 1mm (diameter) is: Al 86%, Ni 9%, Y 3.25%, La 1.75%.

In the Al-TM-RE alloy system, by adding a small amount of Co or La elements, when δ=0.001, the amorphous formation ability of the five-element aluminum-based amorphous alloy system is optimal, and a critical size of 1.5mm (diameter ) of the five-element complete bulk aluminum-based amorphous alloy. In terms of atomic percentage, the alloy composition of the aluminum-based amorphous alloy rod with a critical dimension of 1.5mm (diameter) is: Al 86%, Ni 6.75%, Co 2.25%, Y 3.25%, La 1.75%.

Design principle of the present invention and beneficial effect are as follows:

On the basis of the Al-TM (transition group elements)-RE (rare earth elements) ternary amorphous alloy system, there are different electronic interaction mechanisms between trace additions of TM and RE elements, among which, trace additions of TM elements can cause the Fermi surface diameter in the system , while the micro-addition of RE elements is related to the change of the diameter of the pseudo-Brillouin zone, and the changes of the two have different effects on the amorphous formation ability of the system. According to the above analysis, let δ=|K _P -2K _F |, where 2K _F is the diameter of the Fermi surface, and K _P is the diameter of the pseudo-Brillouin zone. The specific calculation method is: λ is the wavelength of X-rays, θ is the diffraction angle corresponding to the main diffuse peak in the X-ray diffraction spectrum; Z _FEM is the number of electrons contributed by free electrons, Z _hyb is the number of electrons contributed by the electron hybridization effect, and n ₀ is the atomic number density. According to the principle of electronic structure of metallic glasses, when the δ value approaches 0, the total energy of the system tends to be the lowest, and the ability to form amorphous is enhanced. Therefore, according to this method, the amorphous-forming ability of the system can be adjusted to prepare large-sized aluminum-based amorphous alloys. The calculation results show that: when δ=0.009, the amorphous formation ability of the quaternary aluminum-based amorphous alloy is optimal, and an aluminum-based amorphous alloy rod with a critical size of 1 mm in diameter can be prepared, and one of the component ratios is: Al86, Ni6.75, Co2.25, Y5 (at.%), another composition ratio is: Al86, Ni9, Y3.25, La1.75 (at.%); and when δ=0.001, five The elemental aluminum-based amorphous alloy system can reach the best state, and a five-element complete bulk aluminum-based amorphous alloy with a diameter of 1.5mm is prepared, and its composition ratio is: Al86, Ni6.75, Co2.25, Y3. 25, La1.75 (at.%). The proposal of this method solves the problem of a large amount of waste of resources in the composition design of aluminum-based amorphous alloys in the past, and designs the five-element complete bulk aluminum amorphous alloy with the largest size in the world. The invention plays an important role in promoting the expansion of the application range of the light-weight and high-strength aluminum-based amorphous alloy.

Description of drawings

Fig. 1 is a diagram of the alloy composition design method of the present invention; wherein (a)-(l) all make the design composition close to 2K _{F =} Kp;

Fig. 2 is a relation diagram of 2K _F and K _p ;

Fig. 3 is the DSC and XRD photo of the 1.5mm rod (Al ₈₆ Ni _6.75 Co _2.25 Y _3.25 La _1.75 ) sample;

Fig. 4 is a high-resolution TEM photo of Al ₈₆ Ni _6.75 Co _2.25 Y _3.25 La _1.75 alloy.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings, but the embodiments of the present invention are not limited thereto.

The present invention is an alloy composition design method for adjusting and controlling the formation ability of aluminum-based amorphous. The method is based on adding a small amount of different TM and RE elements in the Al-TM (transition group element)-RE (rare earth element) ternary amorphous alloy system. Electron interaction mechanism, let δ=|K _P -2K _F |, where 2K _F is the diameter of the Fermi surface, and K _P is the diameter of the pseudo-Brillouin zone. The specific calculation method is: λ is the wavelength of X-rays, θ is the diffraction angle corresponding to the main diffuse peak in the X-ray diffraction spectrum; Z _FEM is the number of electrons contributed by free electrons, Z _hyb is the number of electrons contributed by the electron hybridization effect, and n ₀ is the atomic number density. And when the δ value is close to 0, the total energy of the system tends to be the lowest, and the ability of amorphous formation is enhanced. Therefore, according to this method, the amorphous-forming ability of the system can be adjusted to prepare large-sized aluminum-based amorphous alloys.

In the Al-TM (transition group element)-RE (rare earth element) alloy system, by adding a small amount of Co or La element, when δ=0.009, the amorphous formation ability of the quaternary aluminum-based amorphous alloy is optimal, and can be prepared Aluminum-based amorphous alloy rods with a critical size of 1 mm in diameter, one of which has a composition ratio of (at.%): Al 86%, Ni 6.75%, Co2.25%, Y5%, and another composition ratio For (at.%): Al 86%, Ni 9%, Y 3.25%, La 1.75%; when δ=0.001, the five-element aluminum-based amorphous alloy system can reach the best state, and the diameter of 1.5mm The five-element complete bulk aluminum-based amorphous alloy has a composition ratio (at.%): Al86%, Ni6.75%, Co2.25%, Y3.25%, La1.75%.

Example 1

Select the alloy composition with the strongest amorphous forming ability (Al ₈₆ Ni ₉ Y ₅ ) in the aluminum-based ternary amorphous alloy, as shown in Figure 1, change the diameter of the pseudo-Brillouin zone (K _P ); change the diameter (2K _F ) of the Fermi surface by adding a small amount of Co atoms, according to the δ value criterion: δ=|K _P -2K _F |, wherein, λ is the wavelength of X-rays, θ is the diffraction angle corresponding to the main diffuse peak in the X-ray diffraction spectrum; Z _FEM is the number of electrons contributed by free electrons, Z _hyb is the number of electrons contributed by electron hybridization effect, n ₀ is the atomic number density (n ₀ =ρN _Av /M, ρ is the density of metallic glass, M is the molar mass, N _Av is Avogadro's constant); and when the δ value is close to 0, the total energy of the system tends to be the lowest, and the amorphous formation ability is enhanced. For the five-element aluminum-based amorphous alloy composition: _Al86 ; _Ni6.75 ; _Co2.25 ; _Y3.25 ; , Z(Ni,Co)=2, Z(Al)=3, Z(Y,La)=3, due to the electronic orbital hybridization effect of Al atom and Ni(Co) atom, Z _hyb ＝C _Ni (n _Ni -8)+C _Co (n _Co -7), n _Ni and nCo values were obtained by measuring the white line peaks of Ni and Co atoms in electron energy loss spectroscopy (EELS). From this, it is calculated that δ=0.001 (shown in FIG. 2 ), which is close to zero. Based on this, an alloy rod with a size of 1.5mm was prepared. The DSC and XRD photos in Fig. 3 and the high-resolution TEM photos in Fig. 4 fully prove that the alloy rod is completely amorphous.

Example 2

The difference with Example 1 is:

The trace addition of La and Co elements is different, and the alloy composition is: Al ₈₆ Ni ₆ Co ₃ Y ₄ La ₁ .

Results: δ(=|K _P -2K _F |)=0.008, which is larger than that of Example 1, the critical dimension is 1.08 mm, and the ability of forming amorphous is lower than that of Example 1.

Example 3

The difference with Example 1 is:

The composition of the La element added in a small amount is different, and the alloy composition is: Al ₈₆ Ni _6.75 Co _2.25 Y ₄ La ₁ .

Results: δ(=|K _P -2K _F |)=0.006, larger than that of Example 1, the critical dimension is 1.25 mm, and the ability to form amorphous is lower than that of Example 1.

Example 4

The difference with Example 1 is:

No Co element is added, and the alloy composition is: Al ₈₆ Ni ₉ Y _3.25 La _1.75 .

Results: δ(=|K _P -2K _F |)=0.009, greater than that of Example 1, the critical dimension is 1 mm, and the ability to form amorphous is lower than that of Example 1.

Example 5

The difference with Example 1 is:

No La element is added, and the alloy composition is: Al ₈₆ Ni _6.75 Co _2.25 Y ₅ .

Results: δ(=|K _P -2K _F |)=0.009, greater than that of Example 1, the critical dimension is 1 mm, and the ability to form amorphous is lower than that of Example 1.

Example 6

The difference with Example 1 is:

The trace addition of La and Co elements is different, and the alloy composition is: Al ₈₆ Ni ₆ Co ₃ Y _3.5 La _1.5 .

Results: The value of δ(=|K _P -2K _F |) is greater than that of Example 1, and the ability to form amorphous is lower than that of Example 1.

Example 7

The difference with Example 1 is:

The composition of the La element added in a small amount is different, and the alloy composition is: Al ₈₆ Ni _6.75 Co _2.25 Y _3.5 La _1.5 .

Results: δ(=|K _P -2K _F |)=0.003, larger than that of Example 1, the critical dimension is 1.32mm, and the ability to form amorphous is lower than that of Example 1.

Example 8

The difference with Example 1 is:

The trace addition of Co elements is different, and the alloy composition is: Al ₈₆ Ni ₆ Co ₃ Y _3.25 La _1.75 .

Results: δ(=|K _P -2K _F |)=0.011, larger than that of Example 1, the critical dimension is 0.92 mm, and the ability to form amorphous is lower than that of Example 1.

Example 9

The difference with Example 1 is:

The composition of trace addition of Co element is different, the alloy composition is: Al ₈₆ Ni _4.5 Co _4.5 Y _3.25 La _1.75 .

Results: δ(=|K _P -2K _F |)=0.015, larger than that of Example 1, the critical dimension is 0.74 mm, and the ability to form amorphous is lower than that of Example 1.

Claims (6)

1. it is a kind of regulate and control aluminium-based amorphous alloy Forming ability alloy component design method, it is characterised in that：The method is according in Al- Electronic action mechanism micro addition TM different from RE elements in TM-RE ternary non-crystaline amorphous metal systems, formulates formula (1), formula (1) rule of presentation is in：When δ values level off to 0 when, the gross energy of system tends to minimum, and amorphous formation ability then strengthens；According to Rule regulates and controls to the amorphous formation ability of the Al-TM-RE ternarys non-crystaline amorphous metal system in formula (1), so as to prepare big The al based amorphous alloy of size；

δ=| K_P-2K_F| (1)；

In formula (1)：2K_FIt is the diameter of Fermi surface, 2K_FCalculation such as formula (2)；K_PIt is the diameter of pseudo- Brillouin zone, K_P Calculation such as formula (3)；

$2K_F=2\sqrt[3]{2{\mathrm{\π}}^2{n}_0{Z}_{FEM}}-2\sqrt[3]{2{\mathrm{\π}}^2{n}_0{Z}_{hyb}}---\left(2\right);$

In formula (2), Z_FEMIt is the electron number of free electron contribution, Z_hybIt is the electron number of electronics hydridization effect contribution, n₀It is atom Number density；

$K_P=\frac{4\mathrm{\π}sin\mathrm{\θ}}{\mathrm{\λ}}---\left(3\right);$

In formula (3), λ is the wavelength of X-ray, and θ is that master disperses the corresponding angle of diffraction in peak in X-ray diffraction spectrum.

2. it is according to claim 1 regulation and control aluminium-based amorphous alloy Forming ability alloy component design method, it is characterised in that：Institute In stating Al-TM-RE ternary non-crystaline amorphous metal systems：TM is transition element, and RE is rare earth element.

3. the alloy component design method of regulation and control aluminium-based amorphous alloy Forming ability according to claim 1 and 2, its feature exists In：In Al-TM-RE alloy systems, by micro addition Co or La elements, when δ=0.009, quaternary al based amorphous alloy Amorphous formation ability it is optimal, can prepare critical dimension be 1mm al based amorphous alloy bar.

4. it is according to claim 3 regulation and control aluminium-based amorphous alloy Forming ability alloy component design method, it is characterised in that：Press Atomic percentage conc meter, the critical dimension is that the alloying component of the al based amorphous alloy bar of 1mm is：Al 86%, Ni 6.75%, Co 2.25%, Y 5%；Or, the critical dimension is for the alloying component of the al based amorphous alloy bar of 1mm： Al 86%, Ni 9%, Y 3.25%, La 1.75%.

5. the alloy component design method of regulation and control aluminium-based amorphous alloy Forming ability according to claim 1 and 2, its feature exists In：In Al-TM-RE alloy systems, by micro addition Co or La elements, when δ=0.001, five yuan of al based amorphous alloy The amorphous formation ability of system is optimal, can prepare five yuan of complete block al based amorphous alloy that critical dimension is 1.5mm.

6. it is according to claim 5 regulation and control aluminium-based amorphous alloy Forming ability alloy component design method, it is characterised in that：Press Atomic percentage conc meter, the critical dimension is that the alloying component of the al based amorphous alloy bar of 1.5mm is：Al 86%, Ni 6.75%, Co 2.25%, Y 3.25%, La 1.75%.