WO2018161380A1 - Tellurium-beryllium-copper alloy and preparation method thereof - Google Patents

Abstract

A tellurium-beryllium-copper alloy, comprising 0.2-2.1 wt.% of Be, 0.1-0.7 wt.% of Te, and a total of ≤ 4 wt.% of Co, Ni, Ti, rare earth elements and impurities, the balance being Cu. The preparation method comprises: a. proportioning, feeding, smelting and casting according to the weight percentages to obtain an ingot blank; b. sequentially carrying out a homogenizing heat treatment, heat working process, cold working process, annealing, solid dissolving and aging heat treatment on the ingot blank obtained in step a to obtain the tellurium-beryllium-copper alloy. By adding tellurium to a beryllium-copper alloy, tellurium can form Cu2Te with the copper matrix. The tellurium-beryllium-copper alloy has good high temperature stability and retains the excellent properties of physical mechanics and corrosion resistance of beryllium-copper, and greatly improves the cutting performance of the materials while protecting the environment, and can also achieve good plasticity.

Description

Beryllium copper alloy and preparation method thereof Technical field

The invention relates to a method for preparing an alloy, in particular to an easy-cut beryllium copper alloy and a preparation method thereof.

Background technique

Beryllium copper is a copper-based alloy material with niobium as the basic alloying element, and is a copper-based alloy strengthened by ageing. After solid solution and aging heat treatment, the material has high strength, hardness and elastic limit, small elastic hysteresis, good stability, and has fatigue resistance, corrosion resistance, wear resistance, low temperature resistance, non-magnetic property, high electrical and thermal conductivity, and impact. It does not produce a series of excellent comprehensive performances such as sparks. It is known as the “king of colored elastic materials” and is widely used in electronics, electrical, communications, instrumentation, telecommunications, light industry, machinery, chemical, coal and other fields. Beryllium copper materials are divided into two categories. The first category is high-strength beryllium copper alloy with a content of 1.6-2.1%, such as American ASTM grades C17200 and C17300, and the second type is high-conductivity germanium with a rhodium content of 0.2-0.7%. Copper alloys, such as American ASTM grades C17500, C17510, and the like.

With the trend of miniaturization of electronic components, the size of electronic components that are turned by beryllium copper alloy rods, wires, and tubes as raw materials is required to be small and miniaturized, and dimensional accuracy is required to be in the order of micrometers. The turning force during the turning of beryllium copper alloys requires the following requirements:

1. The turning force of the material must be reduced to insufficient deformation of the small and micro-sized parts.

2, the material's easy turning ability can meet the requirements of high-speed automatic machine tool turning speed and improve turning efficiency.

Based on the above two points, it is necessary to ensure and improve the inherently excellent comprehensive performance of beryllium copper.

In order to improve the turning performance of beryllium copper alloy, the common method is to add lead to beryllium copper alloy, but the following drawbacks exist:

(1) Lead-containing copper alloys cause environmental pollution during production and use. Lead in lead-containing copper alloys will slowly precipitate out under the influence of impurities in drinking water and organic acids, which endangers human health. The use of lead-bismuth copper alloys in household appliances, children's toys, electronic components, automobiles and other spare parts, the European Union's exemption from the content of lead in copper alloys is being phased out, but there is currently no excellent turning without lead. The present invention solves this problem by replacing the market demand for lead-containing beryllium copper alloy with a beryllium copper alloy. x

(2) Lead is neither dissolved in copper nor forms an intermetallic compound with copper. The melting point of lead is low (327 ° C). Lead-containing beryllium copper alloy is prone to cracking of beryllium copper alloy during hot working, so it contains Lead-bismuth copper alloy has poor thermal processing properties;

In recent years, there have been reports on the addition of antimony to improve the machining performance of copper alloys, but the practical application is limited because the addition of niobium has a great influence on the plasticity of copper alloys, and it is easy to make in plastic processing. The alloy is cracked and thus cannot be processed and formed. The addition of niobium causes fatigue stress cracking and corrosion cracking in the use of the material. Therefore, the niobium element has been strictly used as an impurity element for the serious damage of the performance of the copper alloy in the smelting and processing. Content control.

In summary, the development of an easy-to-cut beryllium copper alloy is one of the important issues that need to be solved.

Summary of the invention

OBJECT OF THE INVENTION: The object of the present invention is to solve the deficiencies of the prior art and to provide a free-cut beryllium copper alloy and a preparation method thereof.

Technical Solution: In order to achieve the above object, the present invention provides a beryllium copper alloy comprising 铍Be 0.2 to 2.1 wt.%, 碲Te 0.1 to 0.7 wt.%, and other elements: cobalt Co, nickel Ni, phosphorus P, and rare earth. Element and impurity element, the sum is ≤ 4wt.%, and the rest is Cu.

The preparation method of the beryllium copper alloy is:

a. batching, feeding, smelting and casting according to the weight percentage to obtain an ingot;

The order of feeding in the smelting process is: cathode copper, copper-nickel intermediate alloy and/or copper-cobalt intermediate alloy and/or rare earth intermediate alloy, copper bismuth intermediate alloy, pure bismuth or copper bismuth intermediate alloy, smelting temperature It is 1100～1300°C, after the solution is dissolved, it is kept for 10-30min, after degassing and removing the impurities, it is allowed to stand for 5-20min, then non-vacuum or vacuum casting or semi-continuous or continuous casting;

b. The ingot obtained in step a is sequentially performed: diffusion annealing, plastic hot working, plastic cold working and annealing, solid solution, aging heat treatment process for the purpose of homogenizing the components, and the bar, wire, and copper of the beryllium copper alloy are processed. Tube material

c. Alternatively, the ingot obtained in the step a is sequentially performed: a diffusion annealing, a direct cold working and an annealing, a solid solution, an aging heat treatment process for the purpose of homogenizing the components, and a bar, wire, tube material obtained by processing the beryllium copper alloy. .

The smelting described in step a is smelting using a vacuum or non-vacuum induction furnace.

The plastic hot working process described in step b is an extrusion, rolling, and forging process.

The cold working process described in step b is a rolling, drawing, and rotary forging process.

In the step c, the ingot obtained in the step a is directly subjected to the homogenization diffusion annealing, and the cold processing including the rolling, drawing and rotary forging processes is directly performed, and the annealing, solid solution and aging heat treatment processes are added in the processing flow.

The smelting described in the step a can be carried out in one shot or in two portions under vacuum smelting conditions.

The two-time feeding is specifically to add the cathode copper, the copper-nickel intermediate alloy and/or the copper-cobalt intermediate alloy and/or the rare earth intermediate alloy for the first time, the second copper-cerium intermediate alloy and the pure tantalum. .

The role of the added elements:

碲: Cu ₂ Te can be formed with a copper matrix;

(1) The second phase is dispersed in the intergranular or crystal, and the second phase is soft and dispersed in the copper matrix, so that the chips are easily broken, thereby improving the cutting performance of the material;

(2) Cu ₂ Te has good high temperature stability and high melting point (1140 ° C), which makes the easy-cut beryllium copper alloy can be subjected to hot working such as hot extrusion, hot rolling and hot forging.

Additional examples of 旁(Te) improving turning performance:

Beryllium copper, an alloy of tantalum (Te) and pure copper, American ASTM standard grade C14500, beryllium copper ^[1] (C14500) alloy has excellent cutting performance and excellent electrical and thermal conductivity, as well as corrosion resistance Performance; is the best copper alloy material in high copper alloy; and has good hot and cold processing performance, forging, casting, extrusion drawing, stamping and stamping.

The role of other elements can be further supplemented: the role of other elements Co, Ni, Ti, the content and role of rare earth elements is the addition range of conventional beryllium copper alloy, in order to maintain the turning performance and high temperature softening resistance due to the addition of antimony elements. Added for physical, mechanical properties other than performance, plastic hot workability and other basic properties. Specifically, the action of Co, Ni, and Ti is to refine grains, hinder grain growth during heating, delay decomposition of solid solution, inhibit grain boundary reaction, reduce hard and brittle γ ₁ phase, and improve age hardening effect. The role of rare earth elements mainly composed of lanthanum, cerium and lanthanum is multifaceted, and is beneficial for improving oxidation resistance, improving electrical conductivity, refining crystal grains and improving mechanical properties. The sum of the above elements and the sum of the weights of lead, sulfur, antimony, silicon and other impurity elements ≤ 4wt.%,

Beneficial effects:

The beryllium copper alloy provided by the invention and the preparation method thereof have the following advantages:

1. Easy to cut: the addition of niobium can form Cu ₂ Te with the copper matrix. This second phase is soft and dispersed in the copper matrix, making the chips easy to break, thus improving the material cutting performance; HPb62-3 (US C36000) has a turning index of 100, beryllium copper has an easy turning level of 65-85, and ordinary beryllium copper has a turning grade of 12-25.

The easy turning level detection method is based on Appendix A of the "Free Cutting Copper Alloy Rod" GB-T 26306-2010 (informative applicability turning detection method), the same below.

2, plastic hot processing stability: bismuth and copper form Cu ₂ Te, high temperature stability, high melting point (1140 ° C), making easy-cut beryllium copper alloy can be carried out such as hot extrusion, hot rolling, hot forging, etc. Hot processing; lead-containing beryllium copper alloy is prone to cracking of beryllium copper alloy during hot working, so lead and antimony copper

Gold hot processing performance is poor;

3. Increasing the high temperature softening temperature point, the niobium alloy of the invention is 75 ° C ± 10 ° C higher than the conventional high niobium copper alloy (the niobium content of 1.7% - 2.1%), which is higher than the conventional low niobium alloy (铍The high temperature softening temperature point of 0.2%-0.6%) is increased by 90 °C ± 10 °C, which expands the working range of the beryllium copper material.

4. The addition of niobium can improve the anti-corrosion ability of beryllium copper alloy.

5, the environmental burden is small: to avoid the environmental hazards of lead in the existing lead-containing copper.

detailed description

The invention will be further elucidated below in conjunction with the examples.

Example

Example 1

Preparation of beryllium copper pipe by extrusion

(1) According to the weight percentage of Table 1, the order of feeding is cathode copper CATH-1, copper-bismuth intermediate alloy (containing 铍4%), pure bismuth, copper-nickel intermediate alloy (containing nickel 10%), copper-cobalt intermediate alloy (Cobalt containing 10%), smelting with 750Kg power frequency cored furnace non-vacuum induction furnace, melting temperature is 1170 ° C, after the solution is dissolved, heat preservation for 15 min, argon gas is introduced to remove impurities and gas, after degassing and impurity removal After standing for 15 minutes, the Φ155 round ingot was cast by hydraulic semi-continuous casting machine, casting temperature was 1100 ° C, argon gas protection, casting speed was 150-250 mm/min, cooling water pressure was 0.3 MPa, sawing and cutting ruler Φ155×330;

(2) The hot ingot is hot-extruded at a temperature of 910 ° C, the extrusion ratio is 53:1, the extruder is a 2150T double-action horizontal extruder, and the outer diameter is Φ71, and the wall thickness is 3.5;

(3) After multiple passes of stretching and solution heat treatment, a tube with an outer diameter of Φ49 and a thickness of 2.75 is obtained, the state is TD04, and then subjected to aging treatment at 480 ° C / 2 h, and the straightening and straightening of the two-roll straightening machine A copper tube having a TH04 state, an outer diameter of Φ45, a wall thickness of 2.7, and a length of 2,500 was obtained.

The cutting performance data of the prepared beryllium copper tube (TH04) is shown in Table 3.

The cutting performance data of the prepared C17510 tube is shown in Table 3.

Table 1 Composition of beryllium copper tube

Be	Co	Ni	Te	Fe	Al	Si	margin
0.4	0.2	1.8	0.35	0.05	0.1	0.08	Cu

Table 2 Mechanical properties (TH04)

tensile strength	720MPa
Vickers hardness	235
Conductivity IACS	58%

Table 3 Cutting index (relative to HPb62-3)

Copper tube (TH04)

C17510 tube (comparative group)

68 to 79%

27%

Example 2

Example 2: Preparation of beryllium copper bar by continuous casting

(1) According to the weight percentage of Table 4, the raw materials are cathode copper CATH-1, copper bismuth intermediate alloy (containing 铍10%), copper bismuth intermediate alloy (containing 碲10%), copper-nickel intermediate alloy (containing nickel 10%) ), copper-cobalt intermediate alloy (containing 10% cobalt), smelting in a vacuum induction furnace, first adding cathode copper CATH-1, copper-bismuth intermediate alloy (containing 碲10%), copper-nickel intermediate alloy (containing nickel 10%), Copper-cobalt intermediate alloy (containing 10% cobalt), after melting, adding copper beryllium intermediate alloy (containing cerium 10%), copper cerium intermediate alloy (containing cerium 10%), melting, heating to 1270 ° C, high temperature slag removal Then, the low power is cooled to 1120 ° C, and the temperature is kept for 20 min. The above process is continuously vacuumed, the vacuum degree is maintained at 8×10 ⁻³ Pa, and then continuous casting is performed by using a non-vacuum level to obtain a Φ22×coil blank;

(2) The billet is passed through a rolling mill and hot-rolled at 790 °C to Φ14, and then subjected to multi-pass solution heat treatment and drawing processing to obtain a Φ7.2×coil rod and a straightening ruler Φ7. 2×2500;

(3) Finally, it is processed by a coreless grinding machine to Φ7±0.01×2500, state TD04, or further subjected to aging treatment at 315° C./2h to obtain a TH04 state.

This product can be mainly used as the raw material for the inner conductor of the RF coaxial connector for turning, which can meet the dimensional accuracy guarantee during the processing of its small size (because the turning force is reduced, the deformation of the part is avoided), and the processing efficiency Claim.

The cutting performance data of the prepared beryllium copper tube (TH04) are shown in Table 6.

The cutting performance data of the prepared C17200 rods are shown in Table 6.

Table 4 Composition of beryllium copper tube and comparison group C17200

Table 5 Mechanical properties

status	TD04	TH04
tensile strength	780MPa	1275
Yield Strength	730MPa	1140
Vickers hardness	245	415

Table 6 Cutting performance (relative to HPb59-1)

The above embodiments are merely illustrative of the technical concept and the features of the present invention. The purpose of the present invention is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention. Range of protection. Equivalent transformations or modifications made in accordance with the spirit of the invention are intended to be within the scope of the invention.

Claims (9)

1. A beryllium copper alloy characterized by comprising: 铍Be 0.2 to 2.1 wt.%, 碲Te 0.1 to 0.7 wt.%, and other elements: cobalt Co, nickel Ni, phosphorus P, rare earth elements and impurity elements, the total sum ≤ 4wt.%, the rest is Cu.
2. A beryllium copper alloy according to claim 1, wherein the beryllium copper alloy is prepared by:

   a. batching, feeding, smelting and casting according to the weight percentage to obtain an ingot;

   The order of feeding in the smelting process is: cathode copper, copper-nickel intermediate alloy and/or copper-cobalt intermediate alloy and/or rare earth intermediate alloy, copper bismuth intermediate alloy, pure bismuth or copper bismuth intermediate alloy, smelting temperature It is 1100～1300°C, after the solution is dissolved, it is kept for 10-30min, after degassing and removing the impurities, it is allowed to stand for 5-20min, then non-vacuum or vacuum casting or semi-continuous or continuous casting;

   b. The ingot obtained in step a is sequentially performed: diffusion annealing, plastic hot working, plastic cold working and annealing, solid solution, aging heat treatment process for the purpose of homogenizing the components, and the bar, wire, and copper of the beryllium copper alloy are processed. Tube material

   c. Alternatively, the ingot obtained in the step a is sequentially performed: a diffusion annealing, a direct cold working and an annealing, a solid solution, an aging heat treatment process for the purpose of homogenizing the components, and a bar, wire, tube material obtained by processing the beryllium copper alloy. .
3. The method for preparing a beryllium copper alloy according to claim 2, wherein the melting in the step a is smelting by vacuum or non-vacuum induction furnace.
4. The method for preparing a beryllium copper alloy according to claim 2, wherein the plastic hot working process described in step b is an extrusion, rolling, and forging process.
5. The method for preparing a beryllium copper alloy according to claim 2, wherein the cold working process described in step b is a rolling, drawing, and rotary forging process.
6. The method for preparing a beryllium copper alloy according to claim 2, wherein the step c is specifically that the ingot obtained in the step a is directly subjected to the uniformizing diffusion annealing, including rolling, drawing, and spinning. Cold processing of the forging process, adding annealing, solid solution, and aging heat treatment processes to the processing flow.
7. The method for preparing a beryllium copper alloy according to claim 2, characterized in that the smelting in the step a can be carried out in one shot or in two portions under vacuum smelting conditions.
8. The method for preparing a beryllium copper alloy according to claim 7, wherein the primary charge is a one-time input of a cathode copper, a copper-nickel intermediate alloy and/or a copper-cobalt intermediate alloy and/or ) rare earth intermediate alloy, niobium intermediate alloy and pure niobium.
9. The method for preparing a beryllium copper alloy according to claim 7, wherein the two feedings are specifically added to the cathode copper, the copper-nickel intermediate alloy and/or the copper-cobalt first time. Alloy and/or rare earth intermediate alloy, etc., second addition of copper-rhenium intermediate alloy and pure niobium.