A method for preparing a Cd rotating target

Abstract

The application discloses a preparation method of a Cd rotating target material and belongs to the technical field of semiconductor materials, and comprises the following steps: (1) installing an inner lining pipe in a mold, metalizing the outer surface of the inner lining pipe, and sealing a mold assembly by a back plate and the mold; (2) preheating the inner wall of the mold and the outer wall of the inner lining pipe; (3) melting Cd ingots and uniformly stirring; (4) pouring the molten Cd into the cavity of the mold assembly and keeping warm; (5) segmenting the mold assembly from top to bottom, with the length of each segment being 100-200 mm, and segmenting and cooling from bottom to top; after each segment is cooled, the segment above is cooled, until the uppermost segment is cooled, solidification is completed, demolding is performed, and the Cd rotating target material is obtained; the Cd rotating target material is uniform in internal microstructure, free of defects and pores, and high in compactness.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of semiconductor materials, in particular to a preparation method of a Cd rotating target material. BACKGROUND

[0002] In recent years, the market dominance in the field of solar cells is still crystalline silicon cells, but the dominance of cadmium telluride-based thin film cells in thin film cells is also obvious.

[0003] The cadmium telluride thin film cell has gradually been industrialized and commercialized from the laboratory stage, and reached 5.7GW in 2019. The cadmium telluride-based thin film solar module includes a cadmium telluride absorption layer, a cadmium sulfide buffer layer, a cadmium stannate, cadmium oxide indium oxide or indium tin oxide window layer. However, the cost of indium tin oxide is high, and in the current environment of cost reduction in the photovoltaic industry, it does not have an advantage.

[0004] The cadmium target and the indium target or the tin target are used for preparing cadmium indium oxide and cadmium stannate thin films by magnetron sputtering in an argon and oxygen atmosphere, serving as a window layer of a cadmium telluride-based thin film solar cell, and the existing cadmium target has defects and uneven microstructure.

[0005] In view of this, the present application is proposed. SUMMARY

[0006] The application aims to overcome the deficiencies in the prior art and provide a preparation method of a Cd rotating target material, which has uniform internal microstructure, no defects and no holes, and high density.

[0007] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows:

[0008] A preparation method of a Cd rotating target material, comprising the following steps:

[0009] (1) installing an inner lining pipe in the inside of a mold, metalizing the outer surface of the inner lining pipe, and sealing the mold assembly with the back plate and the mold;

[0010] (2) preheating the inner wall of the mold and the outer wall of the inner lining pipe;

[0011] (3) melting Cd ingots and stirring them uniformly;

[0012] (4) pouring the molten Cd into the cavity of the mold assembly and keeping warm;

[0013] (5) segmenting the mold assembly from top to bottom, with each segment being 100-200 mm long, and segmenting and cooling from bottom to top, with each segment being cooled, and then the segment above is cooled until the uppermost segment is cooled and solidified, and the Cd rotating target material is obtained by demolding.

[0014] The application preheats the inner wall of the mold and the outer wall of the inner lining tube, melts the Cd ingot, pours the molten Cd into the cavity of the mold assembly, keeps warm, and then performs segmented cooling to obtain a Cd rotating target material with uniform internal microstructure, no defects and no holes, high density, and the Cd rotating target material can be used to prepare cadmium indium oxide and cadmium stannate films under the atmosphere of argon and oxygen by magnetron sputtering with an indium target or a tin target, and serves as a window layer of a cadmium telluride-based thin film solar cell, which has a wide application prospect.

[0015] As a preferred embodiment of the application, the material of the mold is cast iron.

[0016] As a preferred embodiment of the application, the material of the inner lining tube is stainless steel.

[0017] As a preferred embodiment of the application, the purity of the Cd ingot is ≥4N.

[0018] As a preferred embodiment of the application, the preheating temperature is 322-380℃, and by controlling the preheating temperature to be 320-380℃, the heat loss of the melt during pouring can be effectively avoided, and cold shut and underfilling phenomena can be avoided, if the preheating temperature is too low, cold shut and underfilling phenomena are prone to occur, resulting in shrinkage holes, and if the preheating temperature is too high, oxidation and target material shrinkage are prone to occur.

[0019] As a preferred embodiment of the application, the temperature for melting the Cd ingot is 322-380℃.

[0020] As a preferred embodiment of the application, the pouring temperature is 322-380℃, and by controlling the pouring temperature, the melt flowability can be improved, and Cd oxidation and shrinkage problems can be avoided, if the pouring temperature is too low, the melt viscosity is high, gas is difficult to discharge, resulting in residual pores and poor melt flowability, making it difficult to compensate, and resulting in residual shrinkage holes in the target material. Higher pouring temperature not only consumes high power, but also causes oxidation and shrinkage problems of the target material.

[0021] As a preferred embodiment of the application, the temperature for keeping warm is 322-380℃, and the keeping warm time is 4-6min. If the temperature for keeping warm is lower than this temperature, the melt viscosity is still high, or the keeping warm time is too short, gas is difficult to discharge, and the obtained target material has pores, and if the temperature for keeping warm is higher than this temperature, oxidation and shrinkage will occur.

[0022] As a preferred embodiment of the application, the temperature for keeping warm is 350℃, and the keeping warm time is 5min.

[0023] As a preferred embodiment of the application, when the segmented cooling is performed from bottom to top, the cooling temperature rate of each segment is 2-6℃ / min, and the cooling time of each segment is 5-10min.

[0024] The inventor of the present application has found that the thermal expansion coefficient of cadmium reaches 41 mu m.m -1 ·K -1 , while the thermal expansion coefficient of the stainless steel liner is only 14 mu m.m -1 ·K -1 The cadmium target is prone to cracking during the cooling process. At this cooling rate, the Cd dendrite skeleton formation process has enough strength to resist the casting stress, thereby avoiding cracking. However, a too fast cooling rate will cause the target to crack. The present application creatively adopts the segmented cooling method to ensure the gradient solidification of cadmium from bottom to top, expel impurities, oxide inclusions and bubbles from bottom to top, and further obtain a Cd rotating target with uniform internal microstructure, no internal defects and no holes, and high density,

[0025] As a preferred embodiment of the present application, when the segmented cooling is performed from bottom to top, the cooling temperature rate of each segment is 5 DEG C / min, and the cooling time of each segment is 6 min.

[0026] In the technical scheme of the present application, the mold and the inner liner can be adjusted according to the actual situation, so that the size of the mold assembly can be flexibly changed, and the length, outer diameter and inner diameter of the prepared target can be completely controlled, thereby avoiding the cumbersome and expensive process of target binding, and achieving simplicity, high efficiency and low cost.

[0027] It should be noted that the metallization of the outer surface of the inner liner specifically refers to: sealing the end of the inner liner with a high-temperature adhesive tape, heating the inner liner to 322-380 DEG C, and coating the Cd on the outer surface of the inner liner after the Cd is heated into a liquid, so as to form a Cd layer with a thickness of 0.1-0.2 mm on the outer surface of the inner liner.

[0028] The present application has the beneficial effects that: the present application preheats the inner wall of the mold and the outer wall of the inner liner, melts the Cd ingot, pours the molten Cd into the cavity of the mold assembly, and then performs segmented cooling, thereby obtaining a Cd rotating target with uniform internal microstructure, no internal defects and no holes, and high density. The Cd rotating target can be used to prepare cadmium indium oxide and cadmium stannate films in an argon and oxygen atmosphere by magnetron sputtering together with an indium target or a tin target, and can be used as a window layer of a cadmium telluride-based thin film solar cell, thereby having a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 FIG. 1 is a schematic view of a mold assembly of the present application. DETAILED DESCRIPTION

[0030] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0031] In the present application, the open technical features described include both the closed technical solutions consisting of the listed features and the open technical solutions containing the listed features.

[0032] In the present application, if no special description is made, the numerical interval is regarded as continuous and includes the minimum value and the maximum value of the range and each value between the minimum value and the maximum value. Further, when a range is referred to as an integer, each integer between the minimum value and the maximum value of the range is included. In addition, when multiple ranges are provided to describe a feature or a characteristic, the ranges can be combined. In other words, unless otherwise specified, all the ranges disclosed herein should be understood to include any and all sub-ranges falling within the range.

[0033] In the present application, the specific dispersion and stirring treatment method is not particularly limited.

[0034] The components and raw materials used in the embodiments and comparative examples of the present application are commercially available unless otherwise specified, and the components and raw materials used in each parallel experiment are the same.

[0035] Embodiment 1

[0036] A preparation method of a Cd rotating target, comprising the following steps:

[0037] (1) installing an inner lining pipe in a mold, sealing the end of the inner lining pipe with a high-temperature adhesive tape, heating the inner lining pipe to 350℃, coating the outer surface of the inner lining pipe with liquid Cd heated to form a 0.1mm Cd layer on the outer surface of the inner lining pipe, the back plate and the mold forming a mold assembly, linking the inner lining pipe and the outer mold of the inner lining pipe through a base to form a cavity with a total length of 3400mm;

[0038] The material of the mold is cast iron;

[0039] The material of the inner lining pipe is stainless steel;

[0040] (2) preheating the inner wall of the mold and the outer wall of the inner lining pipe to 350℃ and maintaining the temperature;

[0041] (3) melting (maintaining the temperature after melting) Cd ingots with a purity of 4N at 350℃ at a stirring speed of 50rpm;

[0042] (4) Pour the molten Cd (temperature at the time of pouring is 350°C) into the cavity of the mold assembly, and keep the temperature at 350°C for 5 min;

[0043] (5) Segment the mold assembly from top to bottom, with each segment being 200 mm long, and cool each segment from bottom to top, with each segment being cooled for 6 min, until the uppermost segment is cooled and solidification is complete, and the Cd rotating target is obtained by demolding.

[0044] The cooling temperature rate of each segment is 5°C / min, and the cooling time of each segment is 6 min.

[0045] Example 2

[0046] A method for preparing a Cd rotating target, comprising the following steps:

[0047] (1) Install an inner liner tube in the mold, seal the end of the inner liner tube with a high-temperature adhesive tape, heat the inner liner tube to 322°C, and coat the outer surface of the inner liner tube with Cd heated into a liquid, so that a 0.1 mm Cd layer is formed on the outer surface of the inner liner tube, the back plate and the mold form a mold assembly, and the inner liner tube is linked with the outer mold of the inner liner tube through a base to form a cavity with a total length of 3400 mm;

[0048] The material of the mold is cast iron;

[0049] The material of the inner liner tube is stainless steel;

[0050] (2) Preheat the inner wall of the mold and the outer wall of the inner liner tube to 322°C and keep the temperature;

[0051] (3) Melt the Cd ingot with a purity of 4N at 322°C (keep the temperature after melting), and stir uniformly at a speed of 50 rpm;

[0052] (4) Pour the molten Cd (temperature at the time of pouring is 322°C) into the cavity of the mold assembly, and keep the temperature at 322°C for 5 min;

[0053] (5) Segment the mold assembly from top to bottom, with each segment being 200 mm long, and cool each segment from bottom to top, with each segment being cooled for 6 min, until the uppermost segment is cooled and solidification is complete, and the Cd rotating target is obtained by demolding.

[0054] The cooling temperature rate of each segment is 5°C / min, and the cooling time of each segment is 6 min.

[0055] Example 3

[0056] A method for preparing a Cd rotating target, comprising the following steps:

[0057] (1) install the inner liner tube in the mold, seal the end of the inner liner tube with high temperature adhesive tape, heat the inner liner tube to 380℃, coat the outer surface of the inner liner tube with Cd heated into liquid to form a 0.1mm Cd layer on the outer surface of the inner liner tube, the back plate and the mold constitute a mold assembly, link the inner liner tube with the outer mold of the inner liner tube through the base to form a cavity with a total length of 3400mm;

[0058] The material of the mold is cast iron;

[0059] The material of the inner liner tube is stainless steel;

[0060] (2) preheat the inner wall of the mold and the outer wall of the inner liner tube to 380℃ and keep warm;

[0061] (3) melt the Cd ingot with a purity of 4N at 380℃ (keep warm after melting) and stir uniformly at a speed of 50rpm;

[0062] (4) cast the molten Cd (the temperature during casting is 380℃) into the cavity of the mold assembly, keep warm at a temperature of 380℃ for 5min;

[0063] (5) segment the mold assembly from top to bottom, each segment has a length of 200mm, cool from bottom to top, cool each segment and then cool the segment above it until the topmost segment is cooled and solidified, demold to obtain the Cd rotating target material.

[0064] The cooling temperature rate of each segment is 5℃ / min and the cooling time of each segment is 6min.

[0065] Example 4

[0066] A preparation method of a Cd rotating target material, comprising the following steps:

[0067] (1) install the inner liner tube in the mold, seal the end of the inner liner tube with high temperature adhesive tape, heat the inner liner tube to 380℃, coat the outer surface of the inner liner tube with Cd heated into liquid to form a 0.1mm Cd layer on the outer surface of the inner liner tube, the back plate and the mold constitute a mold assembly, link the inner liner tube with the outer mold of the inner liner tube through the base to form a cavity with a total length of 3400mm;

[0068] The material of the mold is cast iron;

[0069] The material of the inner liner tube is stainless steel;

[0070] (2) preheat the inner wall of the mold and the outer wall of the inner liner tube to 380℃ and keep warm;

[0071] (3) melt the Cd ingot with a purity of 4N at 380℃ (keep warm after melting) and stir uniformly at a speed of 50rpm;

[0072] (4) Casting the molten Cd (temperature at the time of casting: 380°C) into the cavity of the mold assembly, and keeping the temperature at 380°C for 5 min;

[0073] (5) Segmenting the mold assembly from top to bottom, with each segment being 200 mm long, and segmentally cooling from bottom to top, with each segment being cooled and then the segment above it being cooled until the uppermost segment is cooled and solidification is completed, and then demolding to obtain the Cd rotating target material.

[0074] The cooling temperature rate of each segment is 2°C / min, and the cooling time of each segment is 10 min.

[0075] Example 5

[0076] A method for preparing a Cd rotating target material, comprising the following steps:

[0077] (1) Installing an inner liner tube in the mold, sealing the end of the inner liner tube with a high-temperature adhesive tape, heating the inner liner tube to 380°C, and coating the outer surface of the inner liner tube with Cd heated into a liquid to form a 0.1 mm Cd layer on the outer surface of the inner liner tube, the back plate and the mold forming a mold assembly, and linking the inner liner tube and the outer mold of the inner liner tube through a base to form a cavity with a total length of 3400 mm;

[0078] The material of the mold is cast iron;

[0079] The material of the inner liner tube is stainless steel;

[0080] (2) Preheating the inner wall of the mold and the outer wall of the inner liner tube to 380°C and keeping the temperature;

[0081] (3) Melting (keeping the temperature after melting) Cd ingots with a purity of 4N at 380°C, and stirring uniformly at a speed of 50 rpm;

[0082] (4) Casting the molten Cd (temperature at the time of casting: 380°C) into the cavity of the mold assembly, and keeping the temperature at 380°C for 5 min;

[0083] (5) Segmenting the mold assembly from top to bottom, with each segment being 200 mm long, and segmentally cooling from bottom to top, with each segment being cooled and then the segment above it being cooled until the uppermost segment is cooled and solidification is completed, and then demolding to obtain the Cd rotating target material.

[0084] The cooling temperature rate of each segment is 6°C / min, and the cooling time of each segment is 5 min.

[0085] Comparative Example 1

[0086] Comparative Example 1 differs from Example 1 in that Comparative Example 1 is not subjected to segmental cooling, and is the same in other aspects.

[0087] A method for preparing a Cd rotating target material, comprising the following steps:

[0088] (1) installing an inner liner tube in a mold, sealing the end of the inner liner tube with a high-temperature adhesive tape, heating the inner liner tube to 350°C, coating the outer surface of the inner liner tube with Cd heated into a liquid to form a 0.1 mm Cd layer on the outer surface of the inner liner tube, the back plate and the mold forming a mold assembly, linking the inner liner tube and the outer mold of the inner liner tube through a base to form a cavity with a total length of 3400 mm;

[0089] The material of the mold is cast iron;

[0090] The material of the inner liner tube is stainless steel;

[0091] (2) preheating the inner wall of the mold and the outer wall of the inner liner tube to 350°C and keeping warm;

[0092] (3) melting Cd ingots with a purity of 4N at 350°C (keeping warm after melting) and stirring uniformly at a speed of 50 rpm;

[0093] (4) pouring the molten Cd (the temperature during pouring is 350°C) into the cavity of the mold assembly, keeping warm at a temperature of 350°C for 5 min;

[0094] (5) cooling the mold assembly at a rate of 5°C / min for 6 min, solidifying, demolding, and obtaining a Cd rotating target material.

[0095] Comparative Example 2

[0096] Comparative Example 2 differs from Example 1 in that the rate of segmented cooling in Comparative Example 2 is different from that in Example 1, and other aspects are the same.

[0097] A method for preparing a Cd rotating target material, comprising the following steps:

[0098] (1) installing an inner liner tube in a mold, sealing the end of the inner liner tube with a high-temperature adhesive tape, heating the inner liner tube to 350°C, coating the outer surface of the inner liner tube with Cd heated into a liquid to form a 0.1 mm Cd layer on the outer surface of the inner liner tube, the back plate and the mold forming a mold assembly, linking the inner liner tube and the outer mold of the inner liner tube through a base to form a cavity with a total length of 3400 mm;

[0099] The material of the mold is cast iron;

[0100] The material of the inner liner tube is stainless steel;

[0101] (2) preheating the inner wall of the mold and the outer wall of the inner liner tube to 350°C and keeping warm;

[0102] (3) melt (after melting, keep warm) the Cd ingot with purity of 4N at 350℃, and stir uniformly at a rotating speed of 50 rpm;

[0103] (4) cast (the temperature at the time of casting is 350℃) the molten Cd into the cavity of the mold assembly, and keep warm at a temperature of 350℃ for 5 min;

[0104] (5) segment the mold assembly from top to bottom, each segment has a length of 200 mm, and segmentally cool from bottom to top, after cooling each segment, cool the segment above it, until the topmost segment is cooled, solidification is completed, demolding is performed, and the Cd rotating target material is obtained.

[0105] The cooling temperature rate of each segment is 10℃ / min, and the cooling time of each segment is 3 min.

[0106] Comparative Example 3

[0107] Comparative Example 3 is different from Example 1 in that the rate of segmental cooling of Comparative Example 3 is different from that of Example 1, and other aspects are the same.

[0108] A preparation method of a Cd rotating target material, comprising the following steps:

[0109] (1) install an inner liner tube in the mold, seal the end of the inner liner tube with a high-temperature adhesive tape, heat the inner liner tube to 350℃, after heating Cd into a liquid, coat the outer surface of the inner liner tube, so that the outer surface of the inner liner tube forms a Cd layer with a thickness of 0.1 mm, the back plate and the mold constitute a mold assembly, link the inner liner tube and the outer mold of the inner liner tube through the base to form a cavity with a total length of 3400 mm;

[0110] The material of the mold is cast iron;

[0111] The material of the inner liner tube is stainless steel;

[0112] (2) preheat the inner wall of the mold and the outer wall of the inner liner tube to 350℃, and keep warm;

[0113] (3) melt (after melting, keep warm) the Cd ingot with purity of 4N at 350℃, and stir uniformly at a rotating speed of 50 rpm;

[0114] (4) cast (the temperature at the time of casting is 350℃) the molten Cd into the cavity of the mold assembly, and keep warm at a temperature of 350℃ for 5 min;

[0115] (5) segment the mold assembly from top to bottom, each segment has a length of 200 mm, and segmentally cool from bottom to top, after cooling each segment, cool the segment above it, until the topmost segment is cooled, solidification is completed, demolding is performed, and the Cd rotating target material is obtained.

[0116] The cooling temperature rate of each section is 1℃ / min, and the cooling time of each section is 30min.

[0117] Comparative Example 4

[0118] Comparative Example 4 is different from Example 1 in that Comparative Example 4 is not subjected to a metallization treatment, and is the same in other aspects.

[0119] A preparation method of a Cd rotating target material, comprising the following steps:

[0120] (1) installing an inner liner tube in the inside of a mold, the back plate and the mold constituting a mold assembly, linking the inner liner tube with an outer mold of the inner liner tube through a base to form a cavity with a total length of 3400mm;

[0121] The material of the mold is cast iron;

[0122] The material of the inner liner tube is stainless steel;

[0123] (2) preheating the inner wall of the mold and the outer wall of the inner liner tube to 350℃ and keeping warm;

[0124] (3) melting (keeping warm after melting) Cd ingots with a purity of 4N at 350℃, and stirring uniformly at a speed of 50rpm;

[0125] (4) pouring the molten Cd (the temperature during pouring is 350℃) into the cavity of the mold assembly, and keeping warm at a temperature of 350℃ for 5min;

[0126] (5) segmenting the mold assembly from top to bottom, each section having a length of 200mm, and segmenting and cooling from bottom to top, each time after cooling a section, cooling the section above it until the topmost section is cooled and solidified, demolding to obtain the Cd rotating target material.

[0127] The cooling temperature rate of each section is 5℃ / min, and the cooling time of each section is 6min.

[0128] Comparative Example 5

[0129] Comparative Example 5 is different from Example 1 in that the preheating temperature of Comparative Example 5 is 300℃, and is the same in other aspects.

[0130] A preparation method of a Cd rotating target material, comprising the following steps:

[0131] (1) installing an inner liner tube in the inside of a mold, sealing the end of the inner liner tube with a high-temperature adhesive tape, heating the inner liner tube to 350℃, and coating the outer surface of the inner liner tube with Cd heated into a liquid to form a Cd layer with a thickness of 0.1mm on the outer surface of the inner liner tube, the back plate and the mold constituting a mold assembly, linking the inner liner tube with an outer mold of the inner liner tube through a base to form a cavity with a total length of 3400mm;

[0132] The material of the mold is cast iron;

[0133] The material of the inner liner tube is stainless steel;

[0134] (2) The inner wall of the mold and the outer wall of the inner liner tube are preheated to 300°C and kept warm;

[0135] (3) The Cd ingot with a purity of 4N is melted at 350°C (after melting, keep warm) and stirred uniformly at a speed of 50 rpm;

[0136] (4) The molten Cd is poured (the temperature at the time of pouring is 350°C) into the cavity of the mold assembly, and kept warm at a temperature of 350°C for 5 min;

[0137] (5) The mold assembly is segmented from top to bottom, each segment being 200 mm long, and is segmented for cooling from bottom to top, each segment being cooled, and then the segment above it is cooled, until the uppermost segment is cooled and solidification is completed, and the Cd rotating target material is obtained by demolding.

[0138] The cooling temperature rate of each segment is 5°C / min, and the cooling time of each segment is 6 min.

[0139] Comparative Example 6

[0140] Comparative Example 6 differs from Example 1 in that the preheating temperature of Comparative Example 5 is 400°C, and the others are the same.

[0141] A preparation method of a Cd rotating target material, comprising the following steps:

[0142] (1) An inner liner tube is installed inside a mold, the end of the inner liner tube is sealed with a high-temperature adhesive tape, the inner liner tube is heated to 350°C, Cd is heated into a liquid and then coated on the outer surface of the inner liner tube to form a Cd layer with a thickness of 0.1 mm on the outer surface of the inner liner tube, a back plate and the mold form a mold assembly, the inner liner tube and the outer mold of the inner liner tube are linked through a base to form a cavity with a total length of 3400 mm;

[0143] The material of the mold is cast iron;

[0144] The material of the inner liner tube is stainless steel;

[0145] (2) The inner wall of the mold and the outer wall of the inner liner tube are preheated to 400°C and kept warm;

[0146] (3) The Cd ingot with a purity of 4N is melted at 350°C (after melting, keep warm) and stirred uniformly at a speed of 50 rpm;

[0147] (4) Pour the molten Cd (temperature at pouring: 350°C) into the cavity of the mold assembly, and keep the temperature at 350°C for 5 min;

[0148] (5) Segment the mold assembly from top to bottom, with each segment being 200 mm long, and cool each segment from bottom to top, with each segment being cooled for 6 min, until the uppermost segment is cooled and solidification is complete, and the Cd rotating target is obtained by demolding.

[0149] The cooling temperature rate of each segment is 5°C / min, and the cooling time of each segment is 6 min.

[0150] Comparative Example 7

[0151] Comparative Example 7 differs from Example 1 in that the holding temperature of Comparative Example 7 is 300°C, and the other conditions are the same.

[0152] A method for preparing a Cd rotating target, comprising the following steps:

[0153] (1) Install an inner liner tube in the mold, seal the end of the inner liner tube with high-temperature adhesive tape, heat the inner liner tube to 350°C, and coat the outer surface of the inner liner tube with liquid Cd heated to form a 0.1 mm Cd layer on the outer surface of the inner liner tube, the back plate and the mold form a mold assembly, and the inner liner tube is linked with the outer mold of the inner liner tube through a base to form a cavity with a total length of 3400 mm;

[0154] The material of the mold is cast iron;

[0155] The material of the inner liner tube is stainless steel;

[0156] (2) Preheat the inner wall of the mold and the outer wall of the inner liner tube to 350°C and keep the temperature;

[0157] (3) Melt the 4N-purity Cd ingot at 350°C (keep the temperature after melting), and stir uniformly at a speed of 50 rpm;

[0158] (4) Pour the molten Cd (temperature at pouring: 350°C) into the cavity of the mold assembly, and keep the temperature at 300°C for 5 min;

[0159] (5) Segment the mold assembly from top to bottom, with each segment being 200 mm long, and cool each segment from bottom to top, with each segment being cooled for 6 min, until the uppermost segment is cooled and solidification is complete, and the Cd rotating target is obtained by demolding.

[0160] The cooling temperature rate of each segment is 5°C / min, and the cooling time of each segment is 6 min.

[0161] Comparative Example 8

[0162] Comparative Example 8 differs from Example 1 in that the holding temperature of Comparative Example 8 is 400°C, and the others are the same.

[0163] A method for preparing a Cd rotating target material, comprising the following steps:

[0164] (1) installing an inner liner tube in a mold, sealing the end of the inner liner tube with a high-temperature adhesive tape, heating the inner liner tube to 350°C, coating the outer surface of the inner liner tube with Cd heated into a liquid to form a 0.1 mm Cd layer on the outer surface of the inner liner tube, the back plate and the mold forming a mold assembly, linking the inner liner tube and the outer mold of the inner liner tube through a base to form a cavity with a total length of 3400 mm;

[0165] The material of the mold is cast iron;

[0166] The material of the inner liner tube is stainless steel;

[0167] (2) preheating the inner wall of the mold and the outer wall of the inner liner tube to 350°C and holding;

[0168] (3) melting (holding after melting) Cd ingots with a purity of 4N at 350°C, and stirring uniformly at a speed of 50 rpm;

[0169] (4) pouring the molten Cd (the temperature during pouring is 350°C) into the cavity of the mold assembly, and holding at a temperature of 400°C for 5 min;

[0170] (5) segmenting the mold assembly from top to bottom, each segment being 200 mm long, and segmenting and cooling from bottom to top, each segment being cooled for 6 min, and then the segment above is cooled until the topmost segment is cooled and solidified, demolding, to obtain a Cd rotating target material.

[0171] The cooling temperature rate of each segment is 5°C / min, and the cooling time of each segment is 6 min.

[0172] Test Example

[0173] According to the examples and comparative examples, 10 groups of target materials are prepared, and the average value is tested.

[0174] The purity of the sample is tested by ICP-MS, and the grain size of the sample is tested by an electron microscope.

[0175] Table 1

[0176]

[0177] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit the protection scope of the present application, and although the present application has been described in detail with reference to the preferred embodiments, it should be appreciated by those skilled in the art that the technical solutions of the present application can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A method for preparing a Cd rotating target, characterized in that: The following steps are involved: (1) Installing the inner liner tube inside the mold, metalizing the outer surface of the inner liner tube, and the back plate and the mold forming a mold assembly; (2) Preheating the inner wall of the mold and the outer wall of the liner tube; (3) Melt the Cd ingot and stir evenly; (4) Casting the molten Cd into the cavity of the mold assembly and keeping it warm; (5) The mold assembly is segmented from top to bottom, with each segment length being 100 to 200 mm, and is cooled segmentally from bottom to top. After each segment is cooled, the segment above it is cooled again until the top segment is cooled, solidification is completed, and demolding is performed to obtain a Cd rotary target; The preheating temperature is 322~380℃; The holding temperature is 322-380°C and the holding time is 4-6 minutes; When cooling in sections from bottom to top, the cooling temperature rate of each section is 2-6°C / min, and the cooling time of each section is 5-10 minutes.

2. The method for preparing a Cd rotary target according to claim 1, wherein: The material of the mold is cast iron.

3. The method for preparing a Cd rotary target according to claim 1, wherein: The material of the inner lining tube is stainless steel.

4. The method for preparing a Cd rotary target according to claim 1, wherein: The purity of the Cd ingot is ≥4N.

5. The method for preparing a Cd rotary target according to claim 1, wherein: The casting temperature is 322-380°C.

6. The method for preparing a Cd rotary target according to claim 1, wherein: The melting temperature of the Cd ingot is 322-380°C.

7. The method for preparing a Cd rotary target according to claim 1, wherein: When cooling is performed in sections from bottom to top, the cooling temperature rate of each section is 5°C / min, and the cooling time of each section is 6 minutes.

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