Multi-principal element alloy tritium target and preparation method thereof

Abstract

The invention discloses a multi-principal-element alloy tritium target and a preparation method thereof. The prepared multi-principal-element alloy tritium target comprises the following components: TiaZrbAcNbdBe (0 < = a < = 100, 0 < = b < = 100, 0 < = c < = 100, 0 < = d < = 100, 0 < = e < = 100, a + b + c + d + e = 100, 40 < = a + b + c < = 70, 30 < = d + e < = 60; a is Sc, Y, Hf, V, Ta; b: Cr, Mo, Mn, Fe, Co, Ni). The preparation method comprises the following steps: preparing a multi-principal-element alloy target material, regulating and controlling the temperature of a substrate, depositing a multi-principal-element alloy film by a magnetron sputtering method, regulating and controlling the tritium filling temperature and the tritium gas pressure, and filling tritium into the multi-principal-element alloy film to prepare the tritium target. The prepared multi-principal-element alloy tritium target has the excellent properties of high tritium storage capacity, high helium containing property, higher reliability under the high-temperature working condition and the like, and has important application prospects in the field of petroleum logging neutron tubes.

Description

Technical Field

[0001] The invention relates to the technical field of neutron tube tritium target preparation, and in particular to a multi-principal element alloy tritium target and a preparation method thereof. Background Art

[0002] In a deuterium-tritium neutron generator, deuterium nuclei accelerated by high voltage are generally used to bombard tritium targets, and high-energy neutrons are produced after deuterium-tritium nuclear fusion occurs. The core component, the tritium target, directly affects the neutron yield, monochromaticity, and even the working time of the neutron tube. Titanium targets have good tritium storage volume density and extremely low room temperature platform pressure, making them the most widely used tritium targets to date. However, titanium targets have some difficult-to-solve defects, such as easy surface oxidation, poor helium solidification ability, complex activation process, and poor reliability under high temperature conditions. The lattice distortion effect of multi-principal alloys is conducive to improving the tritium storage capacity of the alloy, and the hysteresis diffusion effect is conducive to inhibiting the diffusion of helium and the growth of helium bubbles. By regulating the types of principal elements and the ratio of principal elements with strong affinity to hydrogen to principal elements with weak affinity to hydrogen, alloys with excellent hydrogenation kinetics can be obtained, while also having good thermal stability and extremely low room temperature platform pressure. The use of multi-principal alloy target materials to prepare multi-principal alloy tritium targets has good application prospects. In view of the excellent helium solidification performance and potentially excellent tritium storage performance of multi-principal alloys, they have important application prospects in the field of neutron tube tritium targets. In addition, since its components contain a variety of refractory metal elements and lattice distortion characteristics, it is expected to further improve the temperature resistance of its target material and improve the reliability of multi-principal alloy tritium targets under high temperature conditions. There are currently few public reports on multi-principal alloy tritium targets, mainly because the preparation of multi-principal element tritium targets faces technical bottlenecks such as the complexity of the multi-principal alloy components and the complexity of the process for preparing tritium targets. Summary of the invention

[0003] In view of this, an object of the present invention is to provide a multi-principal alloy tritium target and a preparation method thereof.

[0004] The present invention provides a multi-principal alloy tritium target, characterized in that the expression of the multi-principal alloy tritium target is Ti a Zr b A c Nb d B e , wherein a, b, c, d and e represent the atomic ratio of each corresponding component respectively, A and B are optional elements, and A and B elements are not required, and 0≤a≤100, 0≤b≤100, 0≤c≤100, 0≤d≤100, 0≤e≤100, a+b+c+d+e=100, 40≤a+b+c≤70, 30≤d+e≤60; wherein A element is one of Sc, Y, Hf, V, Ta; B element is one of Cr, Mo, Mn, Fe, Co, Ni.

[0005] In addition, the present invention also provides a method for preparing a multi-principal alloy tritium target, characterized in that the preparation method is carried out according to the following steps:

[0006] S1: Multi-principal alloy target

[0007] Weighing high-purity metal particles containing three elements of Ti, Zr, and Nb or containing three elements of Ti, Zr, and Nb and at least one of elements A and B, wherein element A is one of Sc, Y, Hf, V, and Ta; element B is one of Cr, Mo, Mn, Fe, Co, and Ni; placing them in an arc melting furnace in order of melting point from low to high for arc melting, and obtaining a multi-principal alloy target after more than three times of turning melting;

[0008] S2: Deposition of multi-principal alloy films by magnetron sputtering

[0009] Fix the multi-principal alloy target, place the substrate, adjust the substrate temperature to the substrate target temperature, maintain the constant temperature time t, introduce high-purity argon gas into the chamber of the magnetron sputtering equipment, set a certain argon flow rate, set the sputtering power in the DC mode, and start magnetron sputtering after the pre-sputtering is completed;

[0010] S3: Preparation of tritium target by filling multi-principal alloy film with tritium

[0011] S3.1: Vacuum degassing of the multi-principal alloy film, heating the multi-principal alloy film from room temperature to the degassing target temperature, and then keeping the temperature for a certain period of time after heating to the degassing target temperature. The process of step S3.1 is in a high vacuum state;

[0012] S3.2: After the insulation is completed, the multi-principal alloy membrane is filled with tritium, tritium gas of a certain pressure is introduced, the temperature is raised to the tritium filling target temperature, and after the tritium pressure is kept stable, the temperature is lowered to room temperature, the tritium gas is recovered, and the preparation of the multi-principal alloy tritium target is completed.

[0013] Furthermore, in step S1, the purity of the Ti, Zr, A, Nb and B alloy particles is greater than 99.9%.

[0014] Furthermore, in step S2, the target temperature range of the substrate is 400 to 600°C, and the constant temperature time t is 20 to 60 minutes.

[0015] Furthermore, in step S2, the purity of the high-purity argon gas is greater than 99.9%.

[0016] Furthermore, in step S3.1, the degassing target temperature range is 550 to 650°C, and the vacuum degree of the degassing process is less than 5×10 -4 Pa.

[0017] Furthermore, in step S3.2, the target temperature range of tritium filling is 500 to 650°C, and the tritium pressure range is 10 to 25 KPa.

[0018] The principles and beneficial effects of the present invention are:

[0019] 1. The present invention provides a multi-principal element alloy tritium target, which realizes the regulation of the tritium charging amount and phase structure of the multi-principal element alloy tritium target.

[0020] 2. The present invention provides a method for preparing a multi-principal alloy tritium target, which uses a magnetron sputtering method to sputter a multi-principal alloy from a multi-principal alloy target onto a substrate, and the preparation method is simple and effective. By selecting the principal elements Ti, Zr, Hf, V, Ca, Sc, Y, Ta with high affinity to hydrogen and the principal elements Mo, Nb, Cr, Mn, Fe, Co, Ni with poor affinity to hydrogen, and regulating the proportion of each principal element, a multi-principal alloy tritium target with good high temperature resistance and excellent kinetics at room temperature, good thermal stability and extremely low platform pressure at room temperature, as well as higher solid helium performance and higher reliability under high temperature conditions is prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 XRD diagram of the multi-principal element TiZrHfNb2 alloy film prepared when the TiZrHfNb2 alloy and the magnetron sputtering substrate temperatures are RT, 300° C., and 400° C. in Example 1 of the present invention;

[0022] Figure 2 This is a bright field transmission electron microscopic image of the multi-principal element TiZrHfNb2 alloy film prepared in Example 1 of the present invention;

[0023] Figure 3 This is a high-resolution transmission electron microscopic image of the multi-principal element TiZrHfNb2 alloy film prepared in Example 1 of the present invention;

[0024] Figure 4 The multi-principal element TiZrHfNb2 alloy film prepared in Example 1 of the present invention completes tritium absorption to become a multi-principal element TiZrHfNb2 alloy tritium target, and the XRD diagram when the tritium absorption atomic specific capacity is 1.97;

[0025] Figure 5 This is a bright field transmission electron microscopic image of the multi-principal element TiZrHfNb2 alloy tritium target prepared in Example 1 of the present invention.

[0026] Figure 6 This is a high-resolution transmission electron microscopic image of the multi-principal element TiZrHfNb2 alloy tritium target prepared in Example 1 of the present invention when the helium content is 0.22.

[0027] Figure 7 This is a diagram of the helium release coefficient of the multi-principal element TiZrHfNb2 alloy tritium target prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] Example 1

[0029] The present invention provides a multi-principal alloy tritium target, characterized in that the expression of the multi-principal alloy tritium target is Ti a Zr b A c Nb d B e , wherein a, b, c, d and e represent the atomic ratio of each corresponding component respectively, A and B are optional elements, and A and B elements are not required, and 0≤a≤100, 0≤b≤100, 0≤c≤100, 0≤d≤100, 0≤e≤100, a+b+c+d+e=100, 40≤a+b+c≤70, 30≤d+e≤60; wherein A element is one of Sc, Y, Hf, V, Ta; B element is one of Cr, Mo, Mn, Fe, Co, Ni.

[0030] Example 1 uses a multi-principal element TiZrHfNb2 alloy tritium target composed of four elements: Ti, Zr, Hf, and Nb.

[0031] In addition, the present invention also provides a method for preparing a multi-principal alloy tritium target, characterized in that the preparation method is carried out according to the following steps:

[0032] S1: Multi-principal alloy target

[0033] Weighing high-purity metal particles containing three elements of Ti, Zr, and Nb or containing three elements of Ti, Zr, and Nb and at least one of elements A and B, wherein element A is one of Sc, Y, Hf, V, and Ta; element B is one of Cr, Mo, Mn, Fe, Co, and Ni; placing them in an arc melting furnace in order of melting point from low to high for arc melting, and obtaining a multi-principal alloy target after more than three times of turning melting;

[0034] In Example 1, step S1 respectively weighs four high-purity metal particles of Ti, Zr, Hf, and Nb with a purity greater than 99.9%, and places them in an arc melting furnace in order of their melting points from low to high (Ti<Zr<Hf<Nb), selects a current of 500 to 800 A for arc melting, and obtains a multi-principal component TiZrHfNb2 alloy ingot after more than three rounds of melting; the multi-principal component TiZrHfNb2 alloy ingot is subjected to electric spark wire cutting according to the size requirements of the target material of the magnetron sputtering equipment; uses silicon sandpaper and polishing cloth to grind and polish to remove oil and oxide layer on the surface of the alloy ingot, and prepares a TiZrHfNb2 alloy target.

[0035] S2: Deposition of multi-principal alloy films by magnetron sputtering

[0036] Fix the multi-principal alloy target, place the substrate, adjust the substrate temperature to the substrate target temperature, maintain the constant temperature time t, introduce high-purity argon gas into the chamber of the magnetron sputtering equipment, set a certain argon flow rate, set the sputtering power in the DC mode, and start magnetron sputtering after the pre-sputtering is completed;

[0037] In Example 1, step S2 fixes the multi-principal TiZrHfNb2 alloy target, places the substrate, heats up to the substrate target temperature of 400°C, and keeps the temperature constant for 20 minutes. Argon gas with a purity of 99.99% is introduced into the chamber of the magnetron sputtering equipment, and the argon gas flow rate is set to 10 sccm. The sputtering power is set to 200W in DC mode. After the ignition is completed, it is stabilized for 1 minute, and then pre-sputtering is performed for 10 minutes without removing the shielding plate. Then, the formal magnetron sputtering is started, and the sputtering power is turned off after sputtering for 120 minutes.

[0038] S3: Preparation of tritium target by filling multi-principal alloy film with tritium

[0039] S3.1: Vacuum degassing of the multi-principal alloy film, heating the multi-principal alloy film from room temperature to the degassing target temperature, and then keeping the temperature for a certain period of time after heating to the degassing target temperature. The process of step S3.1 is in a high vacuum state;

[0040] In Example 1, step S3.1, the multi-principal alloy film is vacuum degassed, and the temperature is raised from room temperature to the degassing target temperature of 640°C. The whole process ensures that the system is less than 5×10 -4 Pa, heat to the degassing target temperature of 640℃ and keep it for 10min.

[0041] S3.2: After the insulation is completed, the multi-principal alloy membrane is filled with tritium, tritium gas of a certain pressure is introduced, the temperature is raised to the tritium filling target temperature, and after the tritium pressure is kept stable, the temperature is lowered to room temperature, the tritium gas is recovered, and the preparation of the multi-principal alloy tritium target is completed.

[0042] In Example 1, step S3.2 is to charge the multi-principal alloy membrane with tritium. After the heat preservation is completed, 22.32 KPa of tritium gas is introduced and the temperature is raised to the tritium charging target temperature of 645°C. After the tritium pressure of the system remains stable (after the tritium gas is basically saturated), the temperature is lowered to room temperature, the tritium gas is recovered, and the preparation of the multi-principal alloy tritium target is completed.

[0043] Furthermore, in step S1, the purity of the Ti, Zr, A, Nb and B alloy particles is greater than 99.9%.

[0044] Furthermore, in step S2, the target temperature range of the substrate is 400 to 600°C, and the constant temperature time t is 20 to 60 minutes.

[0045] Furthermore, in step S2, the purity of the high-purity argon gas is greater than 99.9%.

[0046] Furthermore, in step S3.1, the degassing target temperature range is 550 to 650°C, and the vacuum degree of the degassing process is less than 5×10 -4 Pa.

[0047] Furthermore, in step S3.2, the target temperature range of tritium filling is 500 to 650°C, and the tritium pressure range is 10 to 25 KPa.

[0048] In Example 1, the prepared multi-principal alloy tritium target is characterized as follows:

[0049] XRD structural analysis: XRD tests were performed on multi-principal element TiZrHfNb2 alloy targets, prepared multi-principal element TiZrHfNb2 alloy films, and multi-principal element TiZrHfNb2 alloy tritium targets after tritium absorption. Figure 1 , 4.

[0050] Transmission electron microscope morphology and organization analysis: Use a focused ion beam transmission electron microscope sample preparation instrument to prepare transmission electron microscope samples with a thickness of less than 100nm from multi-principal element TiZrHfNb2 alloy films and multi-principal element TiZrHfNb2 alloy tritium targets after tritium absorption. Use amorphous C to stick the samples on a copper mesh dedicated to transmission electron microscope, and observe the sample organization morphology with a transmission electron microscope. See Figure 2-3 , 5-7, where examples of helium bubbles are marked by white arrows.

[0051] Element distribution and atomic ratio analysis: The sample organization morphology was observed under a transmission electron microscope, and the sample was subjected to surface distribution energy spectrum scanning (EDX) analysis. By analyzing the energy counts of each principal element, the atomic ratio of each principal element in the multi-principal element alloy tritium target TiZrHfNb2 can be obtained, as shown in Table 1. The atomic ratio of Ti, Zr, Hf, and Nb elements in the multi-principal element alloy tritium target is approximately 20:17:18:45.

[0052] Table 1

[0053] element atom% Ti 20.2 Zr 16.6 Hf 18.1 Nb 45.1

[0054] In summary, the present invention selects and designs elements based on the neutron tube as the application background, adopts the magnetron sputtering method, and prepares a multi-principal element alloy tritium target by reasonably regulating the atomic ratio of the principal elements with strong or weak affinity for hydrogen. The multi-principal element alloy tritium target not only has good high-temperature working reliability, excellent hydrogenation kinetics at room temperature and good helium solidification performance, but also has good thermal stability and extremely low room temperature platform pressure, which solves the application limitations of traditional titanium targets, such as poor helium solidification ability, complex activation process, and poor reliability under high-temperature working conditions.

[0055] The present invention is described in detail above in combination with specific implementation methods and exemplary examples. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments; the above description cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, the technical solution of the present invention and its implementation methods may be subjected to a variety of equivalent substitutions, modifications or improvements, all of which fall within the scope of the present invention; the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A multi-principal alloy tritium target, characterized in that: The expression of multi-principal alloy tritium target is Ti a Zr b A c Nb d B e , wherein a, b, c, d and e represent the atomic ratio of each corresponding component respectively, A and B are optional elements, and A and B elements are not required, and 0≤a≤100, 0≤b≤100, 0≤c≤100, 0≤d≤100, 0≤e≤100, a+b+c+d+e=100, 40≤a+b+c≤70, 30≤d+e≤60; wherein A element is one of Sc, Y, Hf, V, Ta; B element is one of Cr, Mo, Mn, Fe, Co, Ni.

2. A method for preparing a multi-principal alloy tritium target, characterized in that: The preparation method is carried out according to the following steps: S1: Multi-principal alloy target Weighing high-purity metal particles containing three elements of Ti, Zr, and Nb or containing three elements of Ti, Zr, and Nb and at least one of elements A and B, wherein element A is one of Sc, Y, Hf, V, and Ta; element B is one of Cr, Mo, Mn, Fe, Co, and Ni; placing them in an arc melting furnace in order of melting point from low to high for arc melting, and obtaining a multi-principal alloy target after more than three times of turning melting; S2: Deposition of multi-principal alloy films by magnetron sputtering Fix the multi-principal alloy target, place the substrate, adjust the substrate temperature to the substrate target temperature, maintain the constant temperature time t, introduce high-purity argon gas into the chamber of the magnetron sputtering equipment, set a certain argon flow rate, set the sputtering power in the DC mode, and start magnetron sputtering after the pre-sputtering is completed; S3: Preparation of tritium target by filling multi-principal alloy film with tritium S3.1: Vacuum degassing of the multi-principal alloy film, heating the multi-principal alloy film from room temperature to the degassing target temperature, and then keeping the temperature for a certain period of time after heating to the degassing target temperature. The process of step S3.1 is in a high vacuum state; S3.2: After the insulation is completed, the multi-principal alloy membrane is filled with tritium, tritium gas of a certain pressure is introduced, the temperature is raised to the tritium filling target temperature, and after the tritium pressure is kept stable, the temperature is lowered to room temperature, the tritium gas is recovered, and the preparation of the multi-principal alloy tritium target is completed.

3. The method for preparing a multi-principal alloy tritium target according to claim 2, characterized in that: In step S1, the purity of Ti, Zr, A, Nb and B alloy particles is greater than 99.9%.

4. The method for preparing a multi-principal alloy tritium target according to claim 2, characterized in that: In step S2, the target temperature range of the substrate is 400 to 600°C, and the constant temperature time t is 20 to 60 minutes.

5. The method for preparing a multi-principal alloy tritium target according to claim 2, characterized in that: In step S2, the purity of the high-purity argon gas is greater than 99.9%.

6. The method for preparing a multi-principal alloy tritium target according to claim 2, characterized in that: In step S3.1, the degassing target temperature range is 550 to 650°C, and the vacuum degree of the degassing process is less than 5×10 -4 Pa.

7. The method for preparing a multi-principal alloy tritium target according to claim 2, characterized in that: In step S3.2, the tritium charging target temperature range is 500 to 650°C, and the tritium pressure range is 10 to 25 KPa.

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