JPH03294460A - Solution treatment for precipitation hardening copper alloy - Google Patents

Abstract

PURPOSE:To easily and sufficiently subject a copper alloy to precipitation hardening by means of age hardening treatment by subjecting a precipitation hardening copper alloy containing specific amounts of Ti to specific solution treatment and to temporary cooling and further carrying out specific solution treatment and cooling treatment. CONSTITUTION:A precipitation hardening copper alloy which has a composition composed essentially of Cu and containing, as precipitation hardening component, 0.1-3.5%, by weight, Ti and further containing, if necessary, 0.1-3.5% V and further 0.05-4.0% Zr is heated at 900-1000 deg.C for >=10min, by which Ti, V, Zr, etc., are allowed to enter into solid solution in Cu. After this primary solution treatment, this copper alloy is cooled down to the prescribed temp. Then, this copper alloy is heated at a temp. lower than that of the above primary solution treatment and in the range of 800-900 deg.C for >=5min to undergo solid solution heat treatment. After this secondary solution treatment, the copper alloy is cooled at >=5 deg.C/min cooling rate. By this method, the precipitation of a precipitated phase which does not contribute to precipitation hardening in the course of the final cooling stage can be prevented, and the above copper alloy can sufficiently be strengthened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Fields] The present invention relates to Cu-Ti system, Cu-Ti-V system, and C
The present invention relates to a solution treatment method for a u-T i -V-Z r-based precipitation hardening copper alloy.

[Prior Art] In order to sufficiently age harden a precipitation hardening type copper alloy, it is necessary to perform the age hardening treatment after solid solution and homogenization of components contributing to precipitation by solution treatment. As a result of such age hardening treatment, the precipitated phase can be finely distributed in the copperware phase.

However, if cooling of the precipitation-hardening copper alloy during solution treatment is slow, a precipitate phase that does not significantly contribute to precipitation hardening will precipitate in the copper alloy matrix. This is because the pores introduced into the precipitation hardening copper alloy matrix during solution treatment promote the precipitation. Precipitation hardening copper alloys in which precipitated phases that do not significantly contribute to precipitation hardening cannot be sufficiently strengthened even if subjected to age hardening treatment.

Therefore, the conventional solution treatment method for precipitation hardening copper alloys is as follows:
During the solution treatment, the precipitation hardening copper alloy was rapidly cooled at a cooling rate of about 1000° C./min.

Note that billet solution treatment before extrusion in which the mother phase is heated to a temperature at which it becomes a single phase, cake solution treatment before hot rolling, etc. are also included in the scope of solution treatment.

[Problems to be Solved by the Invention] However, in order to efficiently quench precipitation hardening copper alloys by solution treatment, solution treatment equipment capable of quenching is required. Such solution treatment equipment is large and
Equipment prices are also high. Moreover, in the conventional case, the heat capacity of the material had to be reduced, which caused the problem that it was not suitable as an industrial treatment method.

The present invention has been made in view of the above circumstances, and is a precipitation hardening type copper that can be implemented with simple equipment and that can prevent precipitated phases that do not contribute to precipitation hardening from precipitating during the final cooling process. The present invention provides a method for solution treatment of alloys.

[Means for Solving the Problems] The present invention contains Cu as a main component and 0.00% as a precipitation hardening component.
A first solution treatment step of heating a precipitation-hardening copper alloy containing 1 to 3.5% by weight of Ti at a temperature of 900 to 1000° C. for 10 minutes or more to solidly dissolve Ti in Cu, and the first solution a first cooling step in which the copper alloy after the heat treatment is cooled to a predetermined temperature, and the copper alloy after the first cooling step is heated at a temperature lower than the temperature during the first solution heat treatment, and 900℃
a second solution treatment step in which Ti is dissolved in Cu by heating at a temperature of 5 minutes or more, and a second solution treatment step in which the copper alloy after the second solution treatment is cooled at a cooling rate of 5° C./min or more. 1 is a method for solution treatment of a precipitation hardening copper alloy, the method comprising a cooling step;

Further, the present invention provides precipitation hardening copper alloys containing Cu as a main component and 0.1 to 3.5% by weight of Ti and 0.1 to 3.5% by weight of V as precipitation hardening components. 100
A first solution treatment step in which Ti and V are dissolved in Cu by heating at a temperature of 0° C. for 10 minutes or more, and a first cooling step in which the copper alloy after the first solution treatment is cooled to a predetermined temperature. step, and heating the copper alloy after the first cooling step at a temperature lower than the temperature during the first solution treatment and at a temperature of 800 to 9000 C for 5 minutes or more to add Ti and V to Cu. A characteristic feature of the invention is that it comprises a second solution treatment step in which the copper alloy is dissolved in solid solution, and a second cooling step in which the copper alloy after the second solution treatment is cooled at a cooling rate of 5° C./min or more. Solution treatment method for precipitation hardening copper alloy
A precipitation hardening copper alloy containing 3.5 wt% Ti, 0.1-3.5 wt% V, and 0.05-4.0 wt% Zr was heated at a temperature of 900-1000°C for 10 minutes. a first solution treatment step in which Ti, V, and Zr are dissolved in Cu by heating as described above; a first cooling step in which the copper alloy after the first solution treatment is cooled to a predetermined temperature; At a temperature lower than the temperature during the first solution treatment on the copper alloy after the cooling step,
and a second solution treatment step in which Ti%V1 and Zr are dissolved in Cu by heating at a temperature of 800 to 900°C for 5 minutes or more, and the copper alloy after the second solution treatment is heated at 5°C/ This is a solution treatment method for a precipitation hardening copper alloy, characterized by comprising a second cooling step of cooling at a cooling rate of 1 minute or more.

[Function] According to the solution treatment method for precipitation hardening copper alloy of the present invention,
First, by the first solution treatment, components contributing to precipitation hardening are converted into a solid solution. Next, this is cooled to a predetermined temperature. Next, the copper alloy after cooling is subjected to a second solution treatment for a predetermined period of time. During this second solution treatment, the concentration of pores introduced into the precipitation hardening copper alloy matrix in the first solution treatment decreases. Thereby, it is possible to suppress precipitation of a precipitated phase that does not contribute to precipitation hardening in the final cooling step, without rapidly cooling the precipitation hardening copper alloy. As a result, a homogeneous supersaturated solid solution can be obtained, and components contributing to precipitation hardening can be sufficiently precipitated during aging treatment, thereby sufficiently strengthening the precipitation hardening type copper alloy.

[Example] Hereinafter, the solution treatment method for a precipitation hardening copper alloy of the present invention will be explained in the order of its steps.

Precipitation hardening copper alloys to be strengthened include Cu-Ti system, Cu-T
They are i-V type and Cu-Ti-V-Zr type.

The Cu-Ti precipitation hardening type copper alloy has Cu as a main component, and contains 0.1 to 3.5% by weight of Ti1 inevitable impurity and, if necessary, a solid solution strengthening component. If the Ti content is less than 0.1% by weight, a sufficiently strengthened precipitation hardening copper alloy cannot be obtained. In addition, the Ti content is 3
If it exceeds 65% by weight, excessive Ti will be dissolved in the precipitation hardening copper alloy during solution treatment, causing distortion in the precipitation hardening copper alloy crystals. This distortion creates lattice defects in the precipitation-hardened copper alloy crystal. As a result, a precipitation hardening copper alloy with excellent properties cannot be obtained.

Further, the Cu-Ti-V precipitation hardening copper alloy has Cu as a main component and 0.1 to 3.5% by weight of Ti.

It contains 0.1 to 3.5% by weight of V1 inevitable impurities and, if necessary, a solid solution strengthening component. The reason for limiting the content of (2) is the same as in the case of Ti.

In addition, Cu-T 1-V-Z r-based precipitation hardening copper alloys contain Cu as a main component, 0.1 to 3.5 wt% of Ti,
It contains 0.1 to 3.5% by weight of V, 0.05 to 4.0% by weight of Zr, unavoidable impurities, and, if necessary, a solid solution strengthening component.

The reason for limiting the Zr content is the same as in the case of Ti and (2).

The solid solution strengthening component remains solid solution in the alloy even after the age hardening treatment and contributes to improving the strength. As such, P, Al)
Examples include SSn, Zn, and Mns Si. Also,
The content of solid solution strengthening components is 3 for Sn and Mn.
Weight% or less, 0.51ffi% for other items
It is preferable that it is below.

Such a precipitation hardening alloy is subjected to solution treatment as follows.

First, a precipitation hardening copper alloy is subjected to a first solution treatment for 10 minutes or more at the following heating temperature. The heating temperature during the first solution treatment is set at 900 to 1000°C. The first solution treatment is for dissolving components that contribute to precipitation hardening in the precipitation hardening copper alloy. Therefore, the heating temperature during the first solution treatment is higher than the temperature at which the copperware phase of the precipitation hardening copper alloy becomes a single phase, and deterioration such as oxidation or melting of the material does not occur in the copperware single phase region. It is preferable to set it as high as possible within the range. However, near the temperature at which the copperware phase becomes a single phase, it takes a very long time for the copperware phase to become homogenized, which is inefficient. Therefore, the heating temperature during the first solution treatment is preferably set at least 50°C higher than the temperature at which the copperware phase becomes a single phase.

Moreover, the time of the first solution treatment is set to a time sufficient to uniformly dissolve the components contributing to precipitation hardening into the precipitation hardening copper alloy. Specifically, this first solution treatment time is 1
It is desirable to set it to 0 minutes or more.

Next, the precipitation hardening copper alloy after the first solution treatment is cooled to a temperature at which the second solution treatment is performed. Next, the precipitation hardening copper alloy is subjected to a second solution treatment for a predetermined period of time. In addition, the first
The cooling rate when cooling the precipitation-hardened copper alloy after solution treatment to the temperature of the second solution treatment may be maintained at any cooling rate as long as there is no industrial problem.

In addition, the heating temperature during the second solution treatment is 800 to 90°C.
Set to 0℃.

The second solution treatment is for reducing the pores introduced into the precipitation hardening copper alloy matrix by the first solution treatment. If the vacancy concentration in the copper alloy matrix is high, the component elements that precipitate during the cooling process will actively diffuse. In addition, the pores themselves form nucleation sites and increase the amount of precipitated phases that do not contribute to precipitation hardening. Therefore, the pore density is reduced by the second solution treatment to reach an equilibrium pore concentration.

The equilibrium pore concentration refers to a pore concentration that does not interfere with age hardening treatment. By maintaining the temperature during the second solution treatment at a temperature near the temperature at which the copper alloy matrix becomes a single phase, an equilibrium vacancy concentration can be achieved in the copper alloy matrix.

Further, the time for the second solution treatment is set so as to obtain an equilibrium vacancy concentration within the copper alloy matrix.

Specifically, the time for this second solution treatment is preferably set to 5 minutes or more.

The cooling rate of the precipitation hardening copper alloy after the second solution treatment is 5
Set to ℃/min or higher. This is because if the cooling rate is less than 5° C./min, precipitation of precipitated phases that do not contribute to precipitation hardening cannot be sufficiently suppressed in the second cooling step.

In this way, Cu-Ti system, Cu-Ti-V system and Cu
- A Ti-V-Zr precipitation hardening copper alloy is subjected to a first solution treatment, and components contributing to precipitation hardening are dissolved in the blended phase. Next, the precipitation hardening copper alloy is cooled to a temperature for second solution treatment through a first cooling step. Next, this is subjected to a second solution treatment to reduce the concentration of pores introduced into the precipitation hardening copper alloy matrix in the first solution treatment.

Thereafter, a second cooling step forms a homogeneous supersaturated solid solution within the precipitation hardening copper alloy. As a result, components contributing to precipitation hardening in the subsequent age hardening treatment are finely distributed. As a result, the precipitation hardening copper alloy can be sufficiently strengthened.

Examples of experiments conducted to confirm the effects of the present invention will be described below.

Experimental Examples 1 to 3 First, a precipitation hardening copper alloy containing 2.1% by weight of Ti as a precipitation hardening component was heated to 1200° C. in an electric furnace and melted. This molten precipitation-hardening copper alloy was cast into a plate-like body with dimensions of 200 m in length, 80 m in width, and 20 m in thickness. This plate-shaped body was hot rolled at 800°C to a thickness of 5II11. Furthermore, this was cold-rolled to a thickness of 1 mm to produce a thin plate-like body.

Next, the obtained thin plate-shaped body was heated at 950° C. for 30 minutes to undergo a first solution treatment. After the first solution treatment, the thin plate was cooled to 900°C at a cooling rate of 10°C/min. Next, this was held at a temperature of 900° C. for 30 minutes to perform a second solution treatment on the thin plate-like body. Thereafter, the thin plate-like body after the second solution treatment was cooled to room temperature at a cooling rate of 250° C./min.

In this way, a precipitation-hardened copper alloy thin plate (Experimental Example 1) which was subjected to solution treatment according to the present invention was obtained. Also,
A precipitation-hardened copper alloy thin plate (Experimental Example 2.3) was obtained in the same manner as above, except that the cooling rate for cooling to room temperature was 100° C./min and 40° C./min.

The three precipitation-hardened copper alloy thin plates thus obtained were subjected to an age hardening treatment at 450° C. for 30 minutes, and then placed in ice water for quenching. Thereafter, the tensile strength of each precipitation-hardened copper alloy thin plate was examined. The results are shown in Table 1 below along with the solution treatment conditions.

Note that the tensile strength was measured by cutting the thin plate-like body into a predetermined size to prepare a tensile test piece, and attaching the mini test piece to an Amsler type tensile tester.

Comparative Examples 1 to 3 Using the same thin plate body as in Experimental Example 1, it was subjected to solution treatment at 950°C for 60 minutes. Thereafter, the thin plate-shaped body after the heat treatment was cooled to room temperature at a rate of 250° C./min.

In this way, a precipitation-hardened copper alloy thin plate (Comparative Example 1) which had been subjected to conventional solution treatment was obtained.

In addition, the cooling rate to room temperature was 100℃/min, 40℃/min.
A precipitation-hardened copper alloy thin plate-like body of Comparative Example 2.3 was obtained in the same manner as Comparative Example 1 except for the point that the thickness was changed to 1.

The tensile strength of these precipitation-hardened copper alloy thin plates was examined in the same manner as in Experimental Example 1. The results are also listed in Table 1 below.

Experimental Examples 4 to 6 First, 2.0% by weight of Ti10.5 as a precipitation hardening component
Precipitation hardening copper alloy containing % by weight of V was heated in an electric furnace at 1% by weight.
It was heated to 200°C and dissolved. This was rolled in the same manner as in Experimental Example 1 to obtain a thin plate-like body.

Next, the obtained thin plate-shaped body was heated at 950° C. for 30 minutes to undergo a first solution treatment. After the first solution treatment step, the thin plate-shaped body was cooled to 900°C at a cooling rate of 10°C/min.

Next, the thin plate-shaped body was subjected to a second solution treatment by holding at a temperature of 900° C. for 30 minutes. Thereafter, the thin plate-like body after the second solution treatment was cooled to room temperature at a cooling rate of 250° C./min.

In this way, a precipitation hardening type copper alloy thin plate-like body of Experimental Example 4 was obtained. In addition, the cooling rate to room temperature was set to 100°C/min.
Precipitation hardening type copper alloy thin plate bodies of Experimental Example 5.6 were obtained in the same manner as Experimental Example 4 except that the heating rate was 40° C./min.

The tensile strength of these precipitation-hardened copper alloy thin plates was examined in the same manner as in Experimental Example 1 except that the aging temperature was 500°C. The results are also listed in Table 1 below.

Comparative Examples 4 to 6 Using the same thin plate body as in Experimental Example 4, it was subjected to solution treatment at 950°C for 60 minutes. after that.

The thin plate-shaped body after the heat treatment was cooled to room temperature at a cooling rate of 250° C./min.

In this way, a precipitation-hardened copper alloy thin plate of Comparative Example 4, which had been subjected to conventional solution treatment, was obtained. Further, a precipitation-hardened copper alloy thin plate body of Comparative Example 5.6 was obtained in the same manner as Comparative Example 4 except that the cooling rate to room temperature was 100° C./min and 40° C./min.

The tensile strength of these precipitation-hardened copper alloy thin plates was examined in the same manner as in Experimental Example 4. The results are also listed in Table 1 below.

Experimental Examples 7 to 9 First, 2.0% by weight of Ti, 0.5% by weight as precipitation hardening components
A precipitation-hardening copper alloy containing 0.5% by weight of Zr and 0.5% by weight was heated to 1200° C. and melted in an electric furnace. This was rolled in the same manner as in Experimental Example 1 to obtain a thin plate-like body.

Next, the obtained thin plate-shaped body was heated at 950° C. for 30 minutes to undergo a first solution treatment. After the first solution treatment step, the thin plate-shaped body was cooled to 900°C at a cooling rate of 10°C/min.

Next, the thin plate-shaped body was subjected to a second solution treatment by holding at a temperature of 900° C. for 30 minutes. Thereafter, the thin plate-like body after the second solution treatment was cooled to room temperature at a cooling rate of 250° C./min.

In this way, a precipitation hardening type copper alloy thin plate-like body of Experimental Example 7 was obtained. In addition, the cooling rate to room temperature was set to 100°C/min.
Precipitation hardening type copper alloy thin plate bodies of Experimental Examples 8 and 9 were obtained in the same manner as Experimental Example 7 except that the heating rate was 40° C./min.

The tensile strength of these precipitation-hardened copper alloy thin plates was examined in the same manner as in Experimental Example 1, except that the temperature of the age hardening treatment was 530°C. The results are also listed in Table 1 below.

Comparative Examples 7 to 9 Using the same thin plate-shaped body as in Experimental Example 7, it was subjected to solution treatment at 950°C for 60 minutes. Thereafter, the thin plate-shaped body after the heat treatment was cooled to room temperature at a cooling rate of 250° C./min.

In this way, a precipitation-hardened copper alloy thin plate of Comparative Example 7 was obtained which had been subjected to conventional solution treatment.3 In addition, the cooling rate to room temperature was 100°C/min and 40°C/min. In the same manner as in Comparative Example 7, a precipitation-hardened copper alloy thin plate of Comparative Example 8.9 was obtained.

The tensile strength of these precipitation-hardened copper alloy thin plates was examined in the same manner as in Experimental Example 7. The results are also listed in Table 1 below.

Table 1 As is clear from Table 1, the precipitation hardening copper alloys (Experimental Examples 1 to 9) obtained by the solution treatment method of the present invention had high tensile strength after age hardening treatment. . On the other hand, the precipitation hardening copper alloys (Comparative Examples 1 to 9) obtained by conventional solution treatment methods all had low tensile strength after age hardening.

From the above results, it is clear that the solution treatment method for precipitation hardening copper alloys of the present invention has the following effects.

■Precipitation-hardening copper alloys with excellent properties can be efficiently solution-treated without rapid cooling.

■ Solution treatment by heating during hot rolling, solution treatment using a continuous annealing furnace or a bell furnace becomes possible.

[Effects of the Invention] As explained above, the solution treatment method for precipitation hardening copper alloys according to the present invention can be carried out with simple equipment, and does not contribute to precipitation hardening during the final cooling step. It is possible to prevent precipitation of the precipitated phase.

Claims (3)

[Claims] (1) Cu is the main component, and the precipitation hardening component is 0.1~
90% precipitation hardening copper alloy containing 3.5% by weight of Ti
Heat at a temperature of 0 to 1000℃ for 10 minutes or more to convert Ti to Cu.
a first solution treatment step in which the copper alloy is dissolved in solid solution; a first cooling step in which the copper alloy after the first solution treatment is cooled to a predetermined temperature;
The copper alloy after the first cooling step is heated at a temperature lower than the temperature during the first solution treatment and at a temperature of 800 to 900 ° C. for 5 minutes or more to dissolve Ti into Cu. Second
The solution treatment process and the copper alloy after the second solution treatment are heated to 5°C.
1. A method for solution treatment of a precipitation hardening copper alloy, comprising a second cooling step of cooling at a cooling rate of 1/min or more. (2) Cu is the main component, and the precipitation hardening component is 0.1~
A precipitation hardening copper alloy containing 3.5% by weight of Ti and 0.1 to 3.5% by weight of V is heated at a temperature of 900 to 1000°C for 10 minutes or more to dissolve Ti and V into Cu. a first solution treatment step; a first cooling step of cooling the copper alloy after the first solution treatment to a predetermined temperature; A second solution treatment step in which Ti and V are dissolved in Cu by heating at a temperature of 800 to 900° C. for 5 minutes or more at a temperature lower than the above temperature, and the copper after the second solution treatment. A method for solution treatment of a precipitation hardening copper alloy, comprising a second cooling step of cooling the alloy at a cooling rate of 5° C./min or more. (3) Cu is the main component, and the precipitation hardening component is 0.1~
A precipitation hardening copper alloy containing 3.5 wt% Ti, 0.1-3.5 wt% V, and 0.05-4.0 wt% Zr was heated at a temperature of 900-1000°C for 10 minutes. a first solution treatment step in which Ti, V, and Zr are dissolved in Cu by heating as described above; a first cooling step in which the copper alloy after the first solution treatment is cooled to a predetermined temperature; At a temperature lower than the temperature during the first solution treatment on the copper alloy after the cooling step,
and a second solution treatment step in which Ti, V, and Zr are dissolved in Cu by heating at a temperature of 800 to 900°C for 5 minutes or more, and the copper alloy after the second solution treatment is heated at 5°C. 1. A method for solution treatment of a precipitation hardening copper alloy, comprising a second cooling step of cooling at a cooling rate of 1/min or more.