Ni-Fe-W-Al magnetic recording target material and preparation method thereof

Abstract

The invention belongs to the field of manufacturing of magnetic storage targets, and discloses a preparation method of a Ni-Fe-W-Al magnetic recording target, which specifically comprises the following steps of: 1, carrying out annealing heat treatment on an alloy ingot, and discharging and air-cooling after heat preservation is finished; 2, the alloy cast ingot obtained in the step 1 is subjected to first preheating, and free forging operation is immediately conducted after heat preservation is finished; and (3) the alloy ingot obtained in the step (2) is subjected to second preheating, the alloy ingot is taken out and immediately rolled after heat preservation is completed, air cooling is conducted after flattening is conducted after rolling is completed, and finally the finished product Ni-Fe-W-Al alloy target material is obtained through machining. The Ni-Fe-W-Al alloy target material contains Ni atoms, Fe atoms, W atoms and Al atoms, the atomic percent of the Ni atoms ranges from 65% to 75%, and the atomic percent of the Fe atoms ranges from 20% to 30%. Meanwhile, the invention further discloses the Ni-Fe-W-Al alloy target material.

Description

Technical Field

[0001] The invention belongs to the field of magnetic storage target material manufacturing and discloses a Ni-Fe-W-Al series magnetic recording target material and a preparation method thereof. Background Art

[0002] Magnetron sputtering is a commonly used physical vapor deposition thin film technology, which has the advantages of simple equipment, easy control, large coating area and strong adhesion. Sputtering target is a crucial part of magnetron sputtering technology. As a coating raw material, it is used in many fields, such as data storage media, optical coatings and other industries.

[0003] Ni-Fe-W-Al alloy target is a target material used in the field of magnetic storage and belongs to Ni-Fe based alloy material. Ni-Fe alloy has been widely studied due to its low coercivity and excellent anisotropic magnetoresistance, and is used in various magnetic recording devices, such as new sensors, magnetic recording read heads, filters, etc. Compared with pure Ni-Fe alloy, Ni-Fe-W-Al alloy has improved hardness and reduced plastic deformation ability due to the addition of W and Al, which increases the difficulty of target material processing. Traditional forging process is no longer applicable, and it has a higher tendency to crack during forging and rolling, which puts higher requirements on the control of process parameters during the plastic processing of target materials.

[0004] Therefore, the technical problem that needs to be solved in this case is: how to prepare high-performance Ni-Fe-W-Al magnetic recording target materials through the combination of heat treatment and forging processes. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a Ni-Fe-W-Al system magnetic recording target material, which reduces the hardness and brittleness of the alloy by annealing heat treatment, improves its plastic deformation ability, and combines with specific forging operations to reduce the risk of cracking, thereby preparing a high-performance Ni-Fe-W-Al system magnetic recording target material.

[0006] At the same time, the invention also discloses a Ni-Fe-W-Al system magnetic recording target material.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for preparing a Ni-Fe-W-Al system magnetic recording target material specifically comprises the following steps:

[0009] Step 1: subjecting the alloy ingot to annealing heat treatment, and after the heat preservation is completed, taking it out of the furnace and air cooling it;

[0010] Step 2: preheating the alloy ingot obtained in step 1, and immediately performing free forging operation after the heat preservation is completed;

[0011] Step 3: preheating the alloy ingot obtained in step 2 for the second time, taking it out after the heat preservation, and rolling it immediately. After the rolling is completed, it is leveled and air-cooled, and finally machined to obtain a finished Ni-Fe-W-Al alloy target;

[0012] The Ni-Fe-W-Al alloy target contains Ni atoms, Fe atoms, W atoms and Al atoms, the atomic percentage of the Ni atoms is 65-75%, and the atomic percentage of the Fe atoms is 20-30%.

[0013] In the present invention, we add W and Al elements on the basis of Ni-Fe-based alloy materials to prepare Ni-Fe-W-Al alloy target materials. The addition of W is intended to improve the hardness and wear resistance of the alloy while maintaining good magnetic properties. The addition of Al can further optimize the magnetic anisotropy of the alloy, which helps to improve the magnetic recording efficiency. However, the addition of W improves the hardness of the alloy to a certain extent and reduces the plastic deformation ability of the alloy. The addition of Al makes the melting point difference between the components of the alloy larger, resulting in uneven distribution of components, thereby increasing the difficulty of processing the target material.

[0014] In the research of the present invention, it is found that annealing heat treatment of the alloy ingot first can make the distribution of alloy components uniform, and at the same time, it can reduce the hardness and brittleness of the alloy, improve its plastic deformation ability, and be more conducive to forging; in the forging process, the shape of the alloy ingot is first adjusted, and the edges and corners of the ingot are rounded, which can reduce the cracking tendency in the subsequent large deformation plastic processing process; through repeated drawing and upsetting treatment, the coarser grains in the alloy ingot are fully broken, promoting the recrystallization process, thereby refining the grains. In addition, during forging, the interior of the alloy ingot accumulates a lot of heat due to the large deformation, and the edge of the ingot loses heat faster due to contact with the anvil. This temperature difference leads to stress differences between the inside and outside of the ingot, which is one of the main causes of cracking; therefore, the time of each forging is accurately controlled to complete the forging quickly, thereby avoiding cracking.

[0015] Preferably, the atomic percentage ratio of Ni, Fe, W and Al in the alloy ingot described in step 1 is 65-75:20-30:4-7:1-2.

[0016] Preferably, the annealing heat treatment in step 1 is performed at a temperature of 1000-1200° C. and a holding time of 2-4 hours.

[0017] Preferably, the first preheating described in step 2 has a temperature of 900-1000° C. and a holding time of 90-150 min.

[0018] Preferably, the free forging operation described in step 2 specifically comprises the following steps: firstly adjusting the shape of the ingot, rounding the edges and corners of the alloy ingot, then performing a stretching operation, and finally performing an upsetting operation; the forging is repeated 2 to 3 times, each time lasting 2 to 4 minutes.

[0019] Preferably, the deformation amount of the stretching operation is 45% to 65%, and more preferably 55% to 65%.

[0020] In some preferred embodiments of the present invention, the deformation amount of the drawing operation is 45%, 50%, 55%, 60%, and 65%. If the deformation amount is lower than 45%, the internal grains of the alloy will not be sufficiently crushed and the grains cannot be fully refined. If the deformation amount is higher than 65%, excessive drawing will cause excessive deformation of the material, such as cracking, fracture and other defects. Excessive drawing will make the shape control of the alloy material more difficult. At the same time, a higher deformation amount means that more time is required for forging, the surface temperature of the material will drop, and it will be more difficult to continue forging.

[0021] Preferably, the deformation amount of the upsetting operation is 65% to 85%, more preferably 65% ​​to 75%.

[0022] In some preferred embodiments of the present invention, the deformation amount of the upsetting operation is 65%, 70%, 75%, 80%, and 85%. If the deformation amount is lower than 65%, the grains cannot be effectively refined and the internal structure is not uniform enough; insufficient deformation may lead to the inability to effectively eliminate defects such as internal pores; if the deformation amount is higher than 85%, it will cause excessive deformation of the material, resulting in defects such as cracking and fracture; it will also make the shape control of the alloy material in subsequent deformation more difficult.

[0023] Preferably, it is characterized in that, in step 3, the second preheating has a temperature of 1100-1300° C. and a holding time of 90-150 min.

[0024] In addition, a Ni-Fe-W-Al magnetic recording target material is also disclosed, which is prepared by the above-mentioned preparation method.

[0025] The beneficial effects of the present invention are:

[0026] Annealing heat treatment is used to reduce the hardness and brittleness of the Ni-Fe-W-Al alloy, improve its plastic deformation ability, and cooperate with corresponding forging operations to reduce the risk of cracking during the forging process, so as to prepare a Ni-Fe-W-Al alloy target with precise composition control, uniform composition distribution, no segregation, no inclusions, fine and uniform grains, high purity, high density, high and uniform magnetic permeability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0028] Below in conjunction with the embodiment of the present invention, technical solution of the present invention will be clearly and completely described, it is obvious that the described embodiment is only a part of the present invention, rather than all embodiments. Based on the embodiment in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premise belong to the scope of protection of the present invention. It should be noted that, in the embodiment, those who do not indicate specific conditions, are carried out according to the conditions recommended by normal conditions or manufacturers. Reagents used or instruments that do not indicate manufacturers are conventional products that can be obtained by commercial purchase.

[0029] Product information:

[0030] In the following embodiments and comparative examples, the raw alloy ingots were obtained by smelting and casting and then sawing.

[0031] Example 1

[0032] Step 1: Place an alloy ingot with an atomic percentage of 66% Ni, 25% Fe, 7% W, and 2% Al into a box-type resistance furnace for annealing heat treatment at a temperature of 1100° C. for 3 hours, and then take it out of the furnace and air cool it after the insulation is completed.

[0033] Step 2: Place the alloy ingot obtained in step 1 into a box-type annealing furnace for the first preheating, the preheating temperature is 950°C, and the temperature is kept for 120 minutes; forging is performed immediately after the temperature is kept, the shape of the ingot is first adjusted, the edges and corners of the ingot are rounded, and then a stretching operation is performed, the deformation of the stretching operation is 55%, and finally an upsetting operation is performed, and the upsetting deformation is 75%; the above operation is repeated twice, and the single time is 3 minutes.

[0034] Step 3: placing the alloy ingot obtained in step 2 into a box-type annealing furnace for a second preheating, the preheating temperature is 1200°C, and the temperature is kept for 120 minutes; hot rolling is immediately performed after the temperature is kept, and the single pressing amount is 1-5% of the original thickness. As the number of rolling passes increases, the rolling deformation needs to be gradually reduced, and whether the intermediate furnace return is required is determined according to the target blank temperature; after rolling is completed, leveling and air cooling are performed; after cooling, machining is performed to obtain a finished Ni-Fe-W-Al alloy target;

[0035] The above process can refer to Figure 1 .

[0036] Example 2

[0037] Step 1: Place an alloy ingot with an atomic percentage of 75% Ni, 20% Fe, 4% W, and 1% Al into a box-type resistance furnace for annealing heat treatment at a temperature of 1000° C. for 4 hours, and then take it out of the furnace and air cool it after the insulation is completed.

[0038] Step 2: Place the alloy ingot obtained in step 1 into a box-type annealing furnace for the first preheating, the preheating temperature is 950°C, and the temperature is kept for 120 minutes; forging is performed immediately after the temperature is kept, the shape of the ingot is first adjusted, the edges and corners of the ingot are rounded, and then a stretching operation is performed, the deformation of the stretching operation is 55%, and finally an upsetting operation is performed, and the upsetting deformation is 75%; the above operation is repeated twice, and the single time is 3 minutes.

[0039] Step 3: placing the alloy ingot obtained in step 2 into a box-type annealing furnace for a second preheating, the preheating temperature is 1200°C, and the temperature is kept for 120 minutes; hot rolling is immediately carried out after the insulation is completed, and the single pressing amount is 1-5% of the original thickness. As the number of rolling passes increases, the rolling deformation needs to be gradually reduced, and whether intermediate remelting is required is determined according to the target blank temperature; after rolling is completed, it is leveled and then air-cooled; after cooling, it is machined to obtain a finished Ni-Fe-W-Al alloy target.

[0040] Example 3

[0041] Step 1: Place an alloy ingot with an atomic percentage of 65% Ni, 30% Fe, 4% W, and 1% Al into a box-type resistance furnace for annealing heat treatment at a temperature of 1200° C. for 2 hours, and then take it out of the furnace and air cool it after the insulation is completed.

[0042] Step 2: Place the alloy ingot obtained in step 1 into a box-type annealing furnace for the first preheating, the preheating temperature is 950°C, and the temperature is kept for 120 minutes; forging is performed immediately after the temperature is kept, the shape of the ingot is first adjusted, the edges and corners of the ingot are rounded, and then a stretching operation is performed, the deformation of the stretching operation is 55%, and finally an upsetting operation is performed, and the upsetting deformation is 75%; the above operation is repeated twice, and the single time is 3 minutes.

[0043] Step 3: placing the alloy ingot obtained in step 2 into a box-type annealing furnace for a second preheating, the preheating temperature is 1200°C, and the temperature is kept for 120 minutes; hot rolling is immediately carried out after the insulation is completed, and the single pressing amount is 1-5% of the original thickness. As the number of rolling passes increases, the rolling deformation needs to be gradually reduced, and whether intermediate remelting is required is determined according to the target blank temperature; after rolling is completed, it is leveled and then air-cooled; after cooling, it is machined to obtain a finished Ni-Fe-W-Al alloy target.

[0044] Example 4

[0045] Step 1: Place an alloy ingot with an atomic percentage of 66% Ni, 25% Fe, 7% W, and 2% Al into a box-type resistance furnace for annealing heat treatment at a temperature of 1100° C. for 3 hours, and then take it out of the furnace and air cool it after the insulation is completed.

[0046] Step 2: Place the alloy ingot obtained in step 1 into a box-type annealing furnace for the first preheating, the preheating temperature is 1000°C, and the temperature is kept for 90 minutes; forging is performed immediately after the temperature is kept, the shape of the ingot is first adjusted, the edges and corners of the ingot are rounded, and then a stretching operation is performed, the deformation of the stretching operation is 65%, and finally an upsetting operation is performed, and the upsetting deformation is 85%; the above operation is repeated twice, and the single time is 4 minutes.

[0047] Step 3: placing the alloy ingot obtained in step 2 into a box-type annealing furnace for a second preheating, the preheating temperature is 1300°C, and the temperature is kept for 90 minutes; hot rolling is immediately carried out after the insulation is completed, and the single pressing amount is 1-5% of the original thickness. As the number of rolling passes increases, the rolling deformation needs to be gradually reduced, and whether intermediate remelting is required is determined according to the target blank temperature; after rolling is completed, it is leveled and then air-cooled; after cooling, it is machined to obtain a finished Ni-Fe-W-Al alloy target.

[0048] Example 5

[0049] Step 1: Place an alloy ingot with an atomic percentage of 66% Ni, 25% Fe, 7% W, and 2% Al into a box-type resistance furnace for annealing heat treatment at a temperature of 1100° C. for 3 hours, and then take it out of the furnace and air cool it after the insulation is completed.

[0050] Step 2: Place the alloy ingot obtained in step 1 into a box-type annealing furnace for the first preheating, the preheating temperature is 900°C, and the temperature is kept for 150 minutes; forging is performed immediately after the insulation is completed, the shape of the ingot is first adjusted, the edges and corners of the ingot are rounded, and then a stretching operation is performed, the deformation of the stretching operation is 45%, and finally an upsetting operation is performed, and the upsetting deformation is 65%; the above operation is repeated 3 times, and the single time is 2 minutes.

[0051] Step 3: placing the alloy ingot obtained in step 2 into a box-type annealing furnace for a second preheating, the preheating temperature is 1100°C, and the temperature is kept for 150 minutes; hot rolling is immediately carried out after the insulation is completed, and the single pressing amount is 1-5% of the original thickness. As the number of rolling passes increases, the rolling deformation amount needs to be gradually reduced, and whether intermediate remelting is required is determined according to the target blank temperature; after rolling is completed, it is leveled and then air-cooled; after cooling, it is machined to obtain a finished Ni-Fe-W-Al alloy target.

[0052] Comparative Example 1

[0053] The specific experimental steps are substantially the same as those of Example 1, except that the alloy ingot is directly subjected to the operation of step 2 without the annealing heat treatment of step 1.

[0054] Comparative Example 2

[0055] The specific experimental steps are substantially the same as those of Example 1, except that the specific method of forging in Step 2 is as follows: the alloy ingot obtained in Step 1 is placed in a box-type annealing furnace for first preheating at a temperature of 950°C for 120 minutes; forging is performed immediately after the insulation is completed, the shape of the ingot is first adjusted, the edges and corners of the ingot are rounded, and then a stretching operation is performed with a deformation of 70%; finally, an upsetting operation is performed with an upsetting deformation of 75%; the above operation is repeated twice, with a single time of 3 minutes.

[0056] Comparative Example 3

[0057] The specific experimental steps are substantially the same as those of Example 1, except that the specific method of forging in Step 2 is as follows: the alloy ingot obtained in Step 1 is placed in a box-type annealing furnace for first preheating at 950°C for 120 minutes; forging is performed immediately after the insulation is completed, the shape of the ingot is first adjusted, the edges and corners of the ingot are rounded, and then a stretching operation is performed with a deformation of 55%; finally, an upsetting operation is performed with an upsetting deformation of 90%; the above operation is repeated twice, with a single time of 3 minutes.

[0058] Performance Testing

[0059] Purity: GDMS / ICP-OES is used to test purity and composition;

[0060] Average grain size: Observe under metallographic microscope and calculate the average grain size using intercept method;

[0061] Magnetic permeability: Magnetic permeability is tested according to ASTM F2086-01 standard;

[0062] The samples prepared in each embodiment and comparative example were tested, and the specific test results are shown in Table 1.

[0063] Table 1 Alloy target material performance data

[0064] Sample source purity Homogeneity of composition Average grain size Magnetic Permeability Permeability deviation Example 1 3N5 better 62μm 30％ 2.2％ Example 2 4N better 53μm 32％ 1.8％ Example 3 3N5 good 68μm 26％ 2.5％ Example 4 4N better 57μm 28％ 1.6％ Example 5 4N better 74μm 22％ 2.8％ Comparative Example 1 3N5 Poor 72μm 23％ 3.5％ Comparative Example 2 4N Poor Material cracking / / Comparative Example 3 4N Poor Material cracking / /

[0065] Conclusion Analysis

[0066] Analysis of the data of Examples 1 to 5 shows that the finished alloy target materials prepared by the technical solution of the present invention have a purity of more than 3N5, and Examples 2, 4, and 5 even reach 4N; and by controlling specific forging process parameters, the grains are made finer, wherein the average grain size of Example 2 is 53 μm, and the finer the grains, the more conducive to the transmission of the magnetic field. The finished alloy target materials of each embodiment have excellent magnetic permeability, and the magnetic permeability of Example 2 is as high as 32%; in addition, thanks to the annealing heat treatment operation, the component distribution is very uniform, and the magnetic permeability deviation at each location is very small.

[0067] Comparative Example 1 is based on Example 1, but the annealing heat treatment operation is cancelled, and forging is directly performed. Comparative data show that the alloy target material obtained without annealing heat treatment has poor uniformity of component distribution, and the hardness cannot be reduced, which increases the difficulty of forging, and the grains cannot be well refined, and the final magnetic permeability is only 23%.

[0068] Comparative Examples 2 and 3, based on Example 1, increase the drawing deformation to 70% and the upsetting deformation to 90% during forging, respectively, both of which exceed the limited range of the present technical solution. Excessive deformation causes cracking of the material, and the experiment fails.

[0069] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for preparing a Ni-Fe-W-Al based magnetic recording target material, characterized in that: The specific steps include: Step 1: subjecting the alloy ingot to annealing heat treatment, and after the heat preservation is completed, taking it out of the furnace and air cooling it; Step 2: preheating the alloy ingot obtained in step 1, and immediately performing free forging operation after the heat preservation is completed; Step 3: preheating the alloy ingot obtained in step 2 for the second time, taking it out after the heat preservation, and rolling it immediately. After the rolling is completed, it is leveled and air-cooled, and finally machined to obtain a finished Ni-Fe-W-Al alloy target; The Ni-Fe-W-Al alloy target contains Ni atoms, Fe atoms, W atoms and Al atoms, the atomic percentage of the Ni atoms is 65-75%, and the atomic percentage of the Fe atoms is 20-30%.

2. The preparation method according to claim 1, characterized in that: The atomic percentage ratio of Ni, Fe, W and Al in the alloy ingot described in step 1 is 65-75:20-30:4-7:1-2.

3. The preparation method according to claim 1, characterized in that: The annealing heat treatment described in step 1 has a temperature of 1000-1200° C. and a holding time of 2-4 hours.

4. The preparation method according to claim 1, characterized in that: The first preheating described in step 2 has a temperature of 900-1000° C. and a holding time of 90-150 minutes.

5. The preparation method according to claim 1, characterized in that: The specific steps of the free forging operation described in step 2 are: first adjust the shape of the ingot, round the edges and corners of the ingot, then perform a stretching operation, and finally perform an upsetting operation; the forging is repeated 2 to 3 times, and each time lasts 2 to 4 minutes.

6. The preparation method according to claim 5, characterized in that: The single deformation amount of the pulling operation is 45% to 65%.

7. The preparation method according to claim 5, characterized in that: The single deformation amount of the upsetting operation is 65% to 85%.

8. The preparation method according to claim 1, characterized in that: Step 3: The second preheating temperature is 1100-1300° C. and the insulation time is 90-150 minutes.

9. A Ni-Fe-W-Al based magnetic recording target material, prepared by the preparation method according to any one of claims 1 to 8.

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