A method for preparing a copper-silver-calcium alloy plate and applications thereof

Abstract

The application discloses a copper-silver-calcium alloy plate preparation method and application, and belongs to the processing technical field of non-ferrous alloy, and the method comprises the following steps: according to the required proportion of the copper-silver-calcium alloy, copper raw materials, silver raw materials and calcium raw materials are weighed, after the copper is completely melted in a vacuum melting furnace, the silver and the calcium are added, the copper, the silver and the calcium are subjected to melting, heat preservation and slagging in the vacuum melting furnace, and then cooling casting is carried out, so that the as-cast Cu-0.4Ag-0.4Ca alloy is obtained; the as-cast Cu-0.4Ag-0.4Ca alloy is subjected to equal-channel angular extrusion, so that the extruded Cu-0.4Ag-0.4Ca alloy is obtained; the extruded Cu-0.4Ag-0.4Ca alloy is subjected to cold rolling, so that the copper-silver-calcium alloy plate is obtained; the as-cast Cu-0.4Ag-0.4Ca alloy is continuously subjected to equal-channel angular extrusion, so that the copper alloy grains are refined without changing the shape and size of the test piece, the ordered distribution of the reinforcing phase is realized, the fine-grained organizational structure is preliminarily obtained, and the forming performance of the copper-silver-calcium alloy plate and the strength and plasticity of the product are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of non-ferrous alloy processing, and particularly relates to a preparation method and application of a copper-silver-calcium alloy plate. BACKGROUND

[0002] Cu-Ag alloy has good mechanical properties and electrical conductivity and is widely used in high-speed trains, strong magnetic field magnet systems, large generators rotors and integrated circuits and other new and advanced fields. However, the production cost of copper-silver alloy is high, which greatly limits the development in the civil field. In order to solve this problem, while maintaining the excellent properties of the alloy, many scholars have tried to add a third component to the alloy, reduce the content of Ag element, explore the alloying elements or new alloy preparation methods matched with Cu-Ag alloy, and explore the ternary alloy of Cu-Ag-rare earth, Cu-Ag-Cr and Cu-Ag-Sn.

[0003] At present, grain refinement is a recognized effective way to improve the comprehensive performance of materials. By means of severe plastic deformation (SPD) processing, the microstructure of copper alloy can be controlled and its organization can be refined, which can significantly improve its mechanical properties and physical and chemical properties. In recent years, severe plastic deformation technology has attracted widespread attention from scholars at home and abroad. As a new type of SPD processing technology, equal channel angle pressing (ECAP) has developed rapidly and is widely used. A large number of experiments have confirmed that the processing effect of ECAP (angle extrusion technology) on Cu alloy is more significant. The size and shape of the original sample are almost unchanged during the extrusion process, and the structure and performance of the whole sample after extrusion are relatively uniform, and the internal shrinkage defects of the original sample can be eliminated. It is also suitable for large-size samples. However, in order to ensure the smooth progress of the ECAP processing, the extrusion die and the metal material are usually heated to a certain temperature, and the inner cavity of the die generates high temperature during the extrusion process. Dynamic recrystallization occurs during extrusion, and the grains are recovered and grown, so the refinement effect is limited, and the strength and toughness of the finally obtained alloy are not good. SUMMARY

[0004] The purpose of the present application is to provide a preparation method and application of a copper-silver-calcium alloy plate, which can perform ultra-fine crystallization on the as-cast alloy and further improve the strength and toughness of the alloy.

[0005] In order to solve the above problems, the technical scheme adopted by the present application is as follows: a preparation method of a copper-silver-calcium alloy plate, the method comprising the following steps:

[0006] According to the required proportion of copper-silver-calcium alloy, copper raw material, silver raw material and calcium raw material are weighed, after the copper is completely melted in the vacuum melting furnace, silver and calcium are added, and the copper, silver and calcium are subjected to melting, heat preservation and slagging in the vacuum melting furnace, and then the cast Cu-0.4Ag-0.4Ca alloy is obtained by cooling and pouring;

[0007] The cast Cu-0.4Ag-0.4Ca alloy is subjected to equal-channel angular extrusion to obtain an extruded Cu-0.4Ag-0.4Ca alloy.

[0008] The extruded Cu-0.4Ag-0.4Ca alloy is subjected to cold rolling to obtain a copper-silver-calcium alloy plate.

[0009] Further, the equal-channel angular extrusion of the cast Cu-0.4Ag-0.4Ca alloy comprises the following steps:

[0010] The cast Cu-0.4Ag-0.4Ca alloy is pretreated;

[0011] The extrusion die is placed in the vacuum melting furnace and heated to 400℃;

[0012] The cast Cu-0.4Ag-0.4Ca alloy is placed in the channel in the extrusion die and heat preserved for 20 min;

[0013] The extrusion die extrudes the cast Cu-0.4Ag-0.4Ca alloy;

[0014] After each pass of extrusion, the extrusion die is rotated by 90°, and the cast Cu-0.4Ag-0.4Ca alloy is continuously extruded for 8 passes to obtain an extruded Cu-0.4Ag-0.4Ca alloy.

[0015] Further, the method for pretreating the cast Cu-0.4Ag-0.4Ca alloy comprises polishing, ultrasonic cleaning, using anhydrous ethanol for oil removal, and applying graphite lubricant.

[0016] Further, the extrusion die does not need to be heat preserved during the continuous 8-pass extrusion of the cast Cu-0.4Ag-0.4Ca alloy.

[0017] Further, the mass ratio of the copper, silver and calcium is 265:1:1.5, and the purity is greater than 99.9%.

[0018] Further, the temperature range for melting the copper is 1150℃-1250℃.

[0019] Further, the heat preservation time of the copper, silver and calcium in the vacuum melting furnace is 10-15 min, and the pouring temperature is 1100℃-1200℃.

[0020] Further, the cold-rolled single-pass reduction of the as-extruded Cu-0.4Ag-0.4Ca alloy is 0.25±0.02 mm, and the total reduction is 85±1%.

[0021] The application also provides a suture for a semiconductor component, wherein the suture is made of the copper-silver-calcium alloy sheet.

[0022] In the first aspect, the copper-silver-calcium alloy is prepared by weighing the copper raw material, the silver raw material and the calcium raw material according to the required proportion, melting the copper in a vacuum melting furnace, adding the silver and the calcium, and then performing melting, heat preservation and slagging in the vacuum melting furnace, and finally pouring the alloy to obtain the as-cast Cu-0.4Ag-0.4Ca alloy. The as-cast Cu-0.4Ag-0.4Ca alloy is subjected to equal-channel angular extrusion to obtain the as-extruded Cu-0.4Ag-0.4Ca alloy. The as-extruded Cu-0.4Ag-0.4Ca alloy is subjected to cold rolling to obtain the copper-silver-calcium alloy sheet. The continuous equal-channel angular extrusion of the as-cast Cu-0.4Ag-0.4Ca alloy refines the copper alloy grains without changing the shape and size of the sample, realizes the ordered distribution of the reinforcing phase, and preliminarily obtains the fine-grained structure, thereby further enhancing the strength and plasticity of the copper-silver-calcium alloy sheet. Due to the synergistic adjustment of the layer dislocation energy of the Ag and Ca added in the Cu-0.4Ag-0.4Ca alloy, the deformation capacity and refinement effect of the Cu-0.4Ag-0.4Ca alloy during the equal-channel angular extrusion can be obviously improved, so that the continuous multi-pass extrusion can be successfully realized without intermediate heat preservation and heating, thereby simplifying the processing technology and playing a role in improving the quality and efficiency.

[0023] In the second aspect, the as-extruded Cu-0.4Ag-0.4Ca alloy after the equal-channel angular extrusion is subjected to rolling at room temperature, and the rolling reduction is 85%, so as to further refine the grains of the as-extruded Cu-0.4Ag-0.4Ca alloy and obtain the copper-silver-calcium alloy sheet with ultra-fine-grained structure, and the thickness of the copper-silver-calcium alloy sheet is about 0.85 mm. The combined processing method has simple process operation and equipment requirements, can be well combined with modern industrial production, and has good industrial application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The room temperature metallographic structure diagram of the Cu-0.4Ag-0.4Ca as-cast alloy provided in the embodiments of the application;

[0025] Figure 2 The room temperature metallographic structure diagram of the Cu-0.4Ag-0.4Ca as-cast alloy provided in the embodiments of the application after 8-pass equal-channel angular extrusion;

[0026] Figure 3 The image shows the room temperature metallographic structure of the cold-rolled copper-silver-calcium alloy sheet provided in this embodiment of the invention.

[0027] Figure 4 EBSD image of the copper-silver-calcium alloy plate provided in the embodiment of the present invention;

[0028] Figure 5 The tensile curve of the copper-silver-calcium alloy sheet provided in the embodiment of the present invention;

[0029] Figure 6 This is a hardness diagram of the copper-silver-calcium alloy plate provided in an embodiment of the present invention. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0031] This invention provides a method for preparing copper-silver-calcium alloy plates, the method comprising the following steps:

[0032] According to the required ratio of copper, silver and calcium raw materials, copper raw materials and calcium raw materials are weighed. In this embodiment, the Cu used is electrolytic copper. The mass ratio of copper, silver and calcium is 265:1:1.5 and the purity is greater than 99.9%. After the copper is completely melted in the vacuum melting furnace, silver and calcium are added. The copper, silver and calcium are melted, kept at a constant temperature and slag is removed in the vacuum melting furnace. After cooling, the mixture is cast to obtain the as-cast Cu-0.4Ag-0.4Ca alloy.

[0033] The temperature range for smelting copper is 1150℃~1250℃, and in this embodiment, the preferred temperature for copper is 1200℃. After the copper is completely melted in the vacuum smelting furnace, silver and calcium are added, and the holding time is 15-20 minutes. The copper, silver, and calcium are then refined, held, and slag is removed in the vacuum smelting furnace before cooling and casting to prepare the as-cast Cu-0.4Ag-0.4Ca alloy. The refining temperature needs to be reduced to 1100℃, and the refining time is 5 minutes. The holding time is 10-15 minutes, and the casting temperature is 1100℃~1200℃.

[0034] like Figure 1 As shown, compared with the low-alloy Cu-Ag alloy without the addition of Ca, the addition of Ca in this embodiment significantly refines the grain size of the Cu-0.4Ag-0.4Ca as-cast alloy. The eutectic structure formed by the addition of Ca is distributed along the grain boundaries. The composition of the eutectic structure is α-Cu phase + Cu5Ca phase, and the second phase is Cu5Ca phase.

[0035] The as-cast Cu-0.4Ag-0.4Ca alloy is subjected to equal channel angular extrusion to obtain an extruded alloy, the equal channel angular extrusion comprising the following steps:

[0036] The as-cast Cu-0.4Ag-0.4Ca alloy is subjected to pretreatment, the pretreatment comprising: polishing the as-cast Cu-0.4Ag-0.4Ca alloy, ultrasonic cleaning, cleaning oil with anhydrous ethanol, and applying graphite lubricant;

[0037] The extrusion die is heated to 400℃ in a vacuum melting furnace;

[0038] The as-cast Cu-0.4Ag-0.4Ca alloy is placed into the channel in the extrusion die and kept for 20 min;

[0039] The as-cast Cu-0.4Ag-0.4Ca alloy is extruded by the closed extrusion die;

[0040] The extrusion die is rotated by 90° after each pass of extrusion, and the extrusion is continuously performed for 8 passes to obtain an extruded Cu-0.4Ag-0.4Ca alloy;

[0041] The extrusion die continuously extrudes the as-cast Cu-0.4Ag-0.4Ca alloy for 8 passes without heating in the middle, the extrusion die is rotated by 90° after each pass of extrusion, and the extrusion is continuously performed for 8 passes, as shown in Figure 2 , to obtain an extruded Cu-0.4Ag-0.4Ca alloy; after the as-cast Cu-0.4Ag-0.4Ca alloy is subjected to equal channel angular extrusion for 8 passes, the as-cast Cu-0.4Ag-0.4Ca alloy presents a fibrous microstructure, the original large grains of the as-cast Cu-0.4Ag-0.4Ca alloy are elongated along the extrusion direction and fragmented into fine equiaxed grains, and meanwhile the second phase after fragmentation is more uniformly distributed in the matrix; by continuously performing equal channel angular extrusion on the copper-silver-calcium alloy sheet, the copper alloy grains are refined without changing the shape and size of the test piece, the ordered distribution of the reinforcing phase is realized, the fine-grained microstructure is preliminarily obtained, and the strength and plasticity of the copper-silver-calcium alloy sheet are further enhanced.

[0042] Due to the synergistic adjustment of Ag and Ca added in the Cu-0.4Ag-0.4Ca alloy on the stacking fault energy, the deformation capacity and refinement effect of the as-cast Cu-0.4Ag-0.4Ca alloy in the equal channel angular extrusion process can be obviously improved, so that the continuous multi-pass extrusion can be successfully realized without heating in the middle, which not only simplifies the processing technology, but also plays a role in improving quality and efficiency.

[0043] The extruded Cu-0.4Ag-0.4Ca alloy was cold-rolled to obtain a copper-silver-calcium alloy sheet; the single-pass reduction of the extruded Cu-0.4Ag-0.4Ca alloy in cold rolling was 0.25±0.02 mm, the total reduction was 85±1%, and the rolling speed was 10 r / s; Figure 3 As shown, after cold rolling, the extruded Cu-0.4Ag-0.4Ca alloy exhibits a denser fibrous structure, indicating that the grains are further elongated and fragmented. Simultaneously, numerous large-angle grain boundaries are formed, further refining the grains. The ultrafine crystalline microstructure and the uniformly distributed precipitates provide significant strengthening to the alloy. Ultimately, a plate-shaped Cu-0.4Ag-0.4Ca alloy with excellent comprehensive properties was successfully prepared. The copper-silver-calcium alloy plate has a tensile strength ≥600MPa, an elongation ≥5%, and a microhardness increased to 160HV. The thickness of the copper-silver-calcium alloy plate is approximately 0.85mm. This combined processing method has simple operation and equipment requirements, can be well integrated with modern industrial production, and has promising industrial application prospects.

[0044] like Figure 4 As shown, the average grain size of the cast Cu-0.4Ag-0.4Ca alloy after 8 passes of equal channel corner extrusion and cold rolling is 1.94μm, and the proportion of small grains is large, indicating that the copper-silver-calcium alloy plate has a large proportion of recrystallized grains and a high degree of recrystallization.

[0045] like Figure 5 As shown, the as-cast Cu-0.4Ag-0.4Ca alloy has a tensile strength of approximately 210 MPa and an elongation of nearly 60%. After eight passes of equal-channel angular extrusion, the tensile strength of the extruded Cu-0.4Ag-0.4Ca alloy increases to 450 MPa, while the elongation decreases to 13%. The extruded Cu-0.4Ag-0.4Ca alloy is then cold-rolled and composite-processed to form a copper-silver-calcium alloy sheet. The tensile strength of the copper-silver-calcium alloy sheet exceeds 600 MPa, and the elongation is 6%.

[0046] like Figure 6 As shown, the microhardness of the cast Cu-0.4Ag-0.4Ca alloy is 75.9Hv. After 8 passes of equal channel corner extrusion, the microhardness is increased to 140.9Hv. After cold rolling composite processing, the microhardness of the extruded Cu-0.4Ag-0.4Ca alloy is further increased to 161.1Hv.

[0047] Compare with Example 1

[0048] The present comparative example is used to illustrate the influence of the pass of equal channel angular extrusion, in the comparative example, the as-cast Cu-0.4Ag-0.4Ca alloy is subjected to 4 passes of equal channel angular extrusion, and the rest of the operations are the same as in Example 1, and the final copper-silver-calcium alloy plate has a tensile strength of 577 MPa and an elongation of 2.1%.

[0049] Comparative Example 2

[0050] The present comparative example is used to illustrate the influence of the reduction in equal channel angular extrusion, the as-extruded Cu-0.4Ag-0.4Ca alloy is subjected to cold rolling with a reduction of 70% instead of 85%, and the rest of the operations are the same as in Example 1, and the final copper-silver-calcium alloy plate has a tensile strength of 580 MPa and an elongation of 3.7%.

[0051] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present application, and these improvements and modifications should also be considered as falling within the scope of protection of the present application.

Claims

1. A method for preparing a copper-silver-calcium alloy plate, characterized in that, The method includes the following steps: According to the required proportions for the copper-silver-calcium alloy, copper, silver, and calcium raw materials are weighed out. After the copper is completely melted in a vacuum melting furnace, silver and calcium are added. The copper, silver, and calcium are then melted, held at a constant temperature, and slag is removed before cooling and casting to obtain a cast Cu-0.4Ag-0.4Ca alloy. The mass ratio of copper, silver, and calcium is 265:1:1.5, and the purity is greater than 99.9%. The as-cast Cu-0.4Ag-0.4Ca alloy is subjected to equal-channel angular extrusion to obtain an extruded Cu-0.4Ag-0.4Ca alloy; specifically including: Pretreatment was performed on the as-cast Cu-0.4Ag-0.4Ca alloy; The extrusion die is placed in a vacuum melting furnace and heated to 400°C. The as-cast Cu-0.4Ag-0.4Ca alloy was placed into the channel of the extrusion die and held at that temperature for 20 minutes. The extrusion die is used to extrude the cast Cu-0.4Ag-0.4Ca alloy. After each extrusion pass, the extrusion die is rotated 90°, and the extrusion is repeated for 8 consecutive extrusion passes to obtain the extruded Cu-0.4Ag-0.4Ca alloy; The extruded Cu-0.4Ag-0.4Ca alloy was cold-rolled to obtain a copper-silver-calcium alloy sheet. The temperature range for smelting the copper is 1150℃~1250℃; the holding time for the copper, silver, and calcium in the vacuum smelting furnace is 10~15min, and the casting temperature is 1100℃~1200℃; the single-pass reduction of the extruded Cu-0.4Ag-0.4Ca alloy in cold rolling is 0.25±0.02mm, and the total reduction is 85±1%.

2. The method for preparing copper-silver-calcium alloy plates according to claim 1, characterized in that, The method for pretreating the as-cast Cu-0.4Ag-0.4Ca alloy includes: polishing the as-cast Cu-0.4Ag-0.4Ca alloy, ultrasonic cleaning, cleaning and degreasing with anhydrous ethanol, and applying graphite lubricant.

3. The method for preparing copper-silver-calcium alloy plates according to claim 1, characterized in that, The extrusion die continuously extrudes the as-cast Cu-0.4Ag-0.4Ca alloy in 8 passes without the need for heat preservation or heating during the process.

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