JPH044267B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for producing wire, plate or strip material made of copper or copper alloy. More specifically, the present invention relates to a novel method that can be applied to manufacturing wires, plates, or strips made of copper and copper alloys by hot plastic working such as drawing, wire drawing, or extrusion. Prior Art A typical method for producing long products such as wire rods, plates, or strips made of copper or copper alloys is a series of drawing, wire drawing, or extrusion processes performed using dies, rolls, etc. There is hot plastic working. That is, in hot plastic working of metal, by heating the material to be processed to a temperature higher than the recrystallization temperature, workability is maintained well even as the processing progresses, and high quality products can be manufactured. By the way, in general, there is always a strong demand for and realization of improved quality and productivity of industrial products. Hot plastic processed products such as those mentioned above are no exception, and there is a strong demand for efficiently manufacturing products of higher quality. Examining the conventional hot plastic working process from this perspective, we find that no significant progress has been made in recent years, especially in this process, and improvements in the manufacturing method of metal products through hot plastic working are a major development in this field. It is coveted as such. Problems to be Solved by the Invention Therefore, in view of the above-mentioned prior art, the present invention aims to improve the productivity of manufacturing copper products and copper alloy products by hot plastic working, and further improve the quality of the obtained products. The object of the present invention is to provide a new and improved method for manufacturing wires, plates or strips made of copper and copper alloys. Means for Solving the Problems That is, according to the present invention, 60% by weight or more of Si ₃ N ₄
and 1% to 40% by weight of AlN, Al ₂ O ₃ ,
_{Y2O3 ,} MgO, CaO, _ZrO2 , _TiO2 , _HfO2 , SiC,
At least one compound selected from the group consisting of CeO ₂ , BeO, TiN, Mg ₃ N ₂ and/or
A wire rod made of copper and copper alloy, comprising the step of plastically working copper or copper alloy material heated above the recrystallization temperature using a processing tool formed of a sintered body containing Al; A method of manufacturing a plate or strip is provided. Further, according to another aspect of the present invention, 60% by weight or more of Si ₃ N ₄ and 1% by weight or more and 20% by weight or less
AlN, Al ₂ O ₃ , Y ₂ O ₃ , MgO, CaO, ZrO ₂ ,
_TiO2 , _{HfO2 ,} SiC, _CeO2 , BeO, TiN, _Mg3N2
At least one compound selected from the group consisting of: and/or Al, 1% by weight or more and 20% by weight
It is characterized by including the step of plastically working copper or copper alloy material heated above the recrystallization temperature using a processing tool formed from a sintered body containing the following WC and/or Mo ₂ C. A method of manufacturing a wire, plate or strip made of copper and copper alloy is provided. Function The method for manufacturing a wire, plate, or strip according to the present invention has a main feature that it includes a step of performing hot plastic working using a specific plastic working tool described below. Conventionally, plastic working tools in the hot plastic working process are generally made of cemented carbide, die steel, high speed steel, etc. Die steel is used for hot rolling rolls for copper or copper alloy wire, and die steel is used for wire drawing dies. Cemented carbide was preferably used. However, when plastic working tools made of these materials are used to plastically work copper or copper alloys, copper may adhere to the machined surface of the tool, and repeated welding and separation during operation may cause the tool to become damaged. Defects occur on the surface due to peeling or fatigue. This phenomenon is called spalling, and not only does this spalling significantly shorten the life of the tool, but the quality of the product also deteriorates due to defects in the tool due to spalling. By the way, in hot working of metals, processing tools are placed under extremely severe and unique damage environments. Therefore, hot plastic working tools are basically required to have high strength and excellent impact resistance, and furthermore, tools for plastic working of copper and copper alloys are required to have high strength and excellent impact resistance. It is particularly required to have excellent resistance to spalling. Spalling (surface peeling) in hot rolling rolls is generally thought to be caused by thermal, mechanical, and chemical interactions between the roll and the material to be rolled. Here, the thermal action is characterized in that the roll surface periodically contacts the material to be rolled, and is different from the thermal action that a die receives in this respect. The rolling rolls become fatigued due to these heat cycles,
Spalling occurs due to interaction with the rolled material. In addition, the mechanical action is caused by the roll surface being subjected to a high rolling force and being in contact with the material to be rolled at a high speed. Especially in the case of dice,
Compared to rolling rolls, wear has a greater effect on lifespan. Furthermore, the chemical action is related to the reactivity between the material of the roll surface and the material to be rolled, and in particular, the behavior in the case of hot rolling of copper or copper alloy is extremely complicated.
In other words, the surface of the copper or copper alloy material to be processed is
It is oxidized by cooling water and the atmosphere to form CuO. For example, when Si ₃ N ₄ comes into hot contact with CuO, Si is oxidized by the CuO and SiO ₂ is generated. This SiO ₂ diffuses into Cu and eventually CuO−
Generates SiO ₂ eutectic structure. Such CuO−
The _SiO2 eutectic structure exhibits high reactivity from relatively low temperatures, and for this reason _Si3N4 , a ceramic that generally has low reactivity with other materials, _is also highly reactive toward copper and copper alloys. In the case of hot contact, the chemical effects cannot be ignored. In order to withstand these conditions and improve the productivity and quality of copper products and copper alloy products, it is necessary to use plastic processing tools that effectively prevent welding of copper and copper alloys. It is necessary to. Therefore, the present inventors investigated a method for manufacturing copper products and copper alloy products using a plastic working tool that has less welding with the workpiece material, and as a result, succeeded in developing the manufacturing method according to the present invention. . That is, ceramics generally have low reactivity with other substances, and can also be manufactured with sufficient strength. Therefore, as a result of examining various ceramics as materials for plastic working tools, we found that
It has been found that certain ceramics mainly composed of Si ₃ N ₄ are preferable as tools for hot plastic working of copper and copper alloys. That is, when ceramics having a composition mainly composed of Si ₃ N ₄ as described below is used as a composition processing tool, the occurrence of welding is reduced to the minimum, and the life of the plastic processing tool is significantly extended. In addition, spalling due to welding is less likely to occur, and the quality and yield of the resulting copper products or copper alloy products are greatly improved. That is, the plastic working tool used in the method according to the present invention basically needs to have high strength and impact resistance, and for this purpose, it must contain 60% by weight or more of Si ₃ N ₄ . is required. Furthermore, additives added to Si ₃ N ₄ include AlN, Al ₂ O ₃ , Y ₂ O ₃ , MgO, CaO, ZrO ₂ ,
TiO ₂ , HfO ₂ , SiC, CeO ₂ , BeO, TiN,
Examples of effective additives include Mg ₃ N ₂ and Al. Here, the amount of the additive added is 40% by weight or less, and more preferably a range of 5 to 20% by weight is effective, as will be specifically described later. This means that when the additive amount is less than 1% by weight, no significant additive effect is observed, whereas when the additive amount exceeds 40% by weight, as mentioned above,
This is because the content of Si ₃ N ₄ is insufficient and the tool becomes brittle, making it impossible to achieve sufficient strength as a composition processing tool. Furthermore, according to one aspect of the present invention, in addition to the above-mentioned additives, adding carbides such as WC and/or Mo ₂ C is also effective in improving the strength of the tool. However, if the content of such carbide additive exceeds 20% by weight, it is not preferable because the reactivity between the resulting plastic working tool and the workpiece material increases. Further, if the amount added is less than 1% by weight, no significant effect will be observed, so the amount added is preferably 1% by weight or more. Furthermore, it is known that additives such as metals such as B, Fe, Co, and Ni are effective in small amounts. Note that the plastic working tool used in the manufacturing method according to the present invention is made of a specific ceramic mainly composed of Si ₃ N ₄ as described above. Here, the methods for producing Si ₃ N ₄ ceramic products include a reaction sintering method in which a molded body of Si metal powder is nitrided, and a powder metallurgy method in which Si ₃ N ₄ powder and additive powder are mixed and sintered. Two methods are known. It is known that the former method leaves 10% or more of porosity in the final product, but ceramics with such a high porosity have low strength and are therefore not suitable for use in the method of the present invention. Specifically, a strength that can be effectively used in the method of the present invention is achieved when the porosity is 5% or less. Therefore, in the method of the present invention, it is possible to advantageously use plastic working tools produced by powder metallurgy, whose quality and properties can be controlled by using appropriate additives. Regarding the Si ₃ N ₄ sintered body, it is possible to use either the α-type or β-type crystal system without any difference in effectiveness. Hereinafter, the present invention will be described in more detail by giving specific examples, but the following disclosure is only one example of the present invention and does not limit the technical scope of the present invention in any way. Example 1 Commercially available powders of Si ₃ N ₄ , Al ₂ O ₃ and Y ₂ O ₃ were
They were weighed so that the proportions were 85% by weight, 7% by weight, and 8% by weight, respectively, and after thoroughly mixing in a ball mill, they were pressed and molded at a pressure of 1 t/cm ² .
The obtained molded body was heated for 1800 min under a nitrogen atmosphere of 25 atm.
A die for hot extrusion was prepared by sintering at ℃ for 1 hour. Using the dice obtained as above,
Brass material was extruded and the plastic working process was evaluated based on the life of the die. The extrusion process was carried out at a temperature of 800°C and an area reduction rate of 40%. Also, for comparison, under the same conditions,
The same process was carried out using commercially available cemented carbide dies, and the process was similarly evaluated by the effective run time of the dies. As a result of the above experiments, one die could be used for 6800 hours in the plastic working process performed by the method according to the present invention, and the quality of the obtained product (mainly surface texture) was also high. In contrast, in the conventional plastic forming process using cemented carbide dies, the dies became unusable after 2,500 hours. The quality of the product also deteriorated as it approached the end of its lifespan. When the life of these dies and the quality of the product were evaluated together, the manufacturing method according to the present invention had improved productivity by up to 300% compared to the conventional manufacturing method. Example 2 Mixtures of compounds and their contents (wt%) as shown in Table 1 were prepared, and hot rolling rolls for copper wire and copper plates were produced under the same conditions as in Example 1. This hot rolling roll for copper wire is placed in the final stage of the block mill, and the processing rate is 18% and the rolling speed is 25 m/min.
Copper wire was rolled at a material heating temperature of approximately 850°C. As an evaluation of this experiment, the roll life and product quality are also shown in Table 1.

[Table] Example 3 Commercially available Si ₃ N ₄ , SiC, Y ₂ O ₃ , and MgO powders were mixed at 80% by weight, 10% by weight, 5% by weight, and 5% by weight, respectively.
A guide roller for drawing copper wire was prepared using the same method and conditions as in Example 1 by mixing the components in a proportion of % by weight. However, the sintering temperature was 1700°C. Using the guide roller thus obtained, copper wire was actually drawn. As in Example 1, the implementation results were evaluated based on the life of the tool, the condition of the tool at the end of its life, and the quality of the obtained product. Further, as in Example 1, a comprehensive evaluation including product yield was added to the evaluation as productivity.
The evaluation results are also shown in Table 2. In Table 2, product quality is indicated using the same symbols as in Table 1. For comparison, copper wire was drawn using the same equipment using commercially available guide rollers made of cemented carbide and alumina ceramic, and evaluated in the same manner as in the examples. The evaluation results are also shown in Table 2. The conditions for the wire drawing process in this example and comparative example were a wire drawing speed of 15 m/sec and a material temperature of 900° C. during processing.

[Table] Effects of the Invention As explained in detail above, the method for manufacturing copper and copper alloy wires, plates, or strips according to the present invention can be performed simply by using ceramics as the plastic working tool. This not only extends the life of processing tools, but also improves product quality and yield. That is, in the method according to the present invention, a hot plastic working tool made of a Si ₃ N ₄ sintered body having a specific composition and low porosity is used, and the welding of copper or copper alloy during processing is avoided. This effectively prevents spalling on the tool surface. Therefore, there is less damage to the tool due to spalling, and the quality of the manufactured product is also high. Thus, according to the method of the present invention, overall productivity can be significantly improved in the manufacturing process of copper products or copper alloy products.

Claims (1)

[Claims] 1 60% by weight or more of Si ₃ N ₄ and 1% by weight or more and 40% by weight of AlN, Al ₂ O ₃ , Y ₂ O ₃ , MgO, CaO,
ZrO ₂ , TiO ₂ , HfO ₂ , SiC, CeO ₂ , BeO, TiN,
At least one selected from the group consisting of Mg ₃ N ₂
Copper and copper alloy material characterized by including a step of plastic working copper or copper alloy material heated to a recrystallization temperature or higher using a processing tool formed of a sintered body containing a seed compound and/or Al. A method for producing copper alloy wire, plate or strip material. 2 60% by weight or more of Si ₃ N ₄ and 1% by weight or more and 20% by weight of AlN, Al ₂ O ₃ , Y ₂ O ₃ , MgO, CaO,
ZrO ₂ , TiO ₂ , HfO ₂ , SiC, CeO ₂ , BeO, TiN,
At least one selected from the group consisting of Mg ₃ N ₂
Seed compound and/or Al, 1% by weight or more
Using a processing tool formed of a sintered body containing 20% by weight or less of WC and/or Mo ₂ C,
A method for producing wire, plate or strip material made of copper or copper alloy, the method comprising the step of plastically working copper or copper alloy material heated to a temperature equal to or higher than the recrystallization temperature.