JPH04221032A - High strength and high conductivity copper alloy for die for plastic molding and its manufacture - Google Patents

Abstract

PURPOSE:To offer a copper alloy material for a die for plastic molding easy to manufacture, high in high strength and high temp. strength and furthermore excellent in thermal conductivity. CONSTITUTION:This copper alloy has features of contg., by weight, 1.0 to 4.0% Ti, contg., as accessory components, 0.001 to 3.0% of one or >= two kinds among the group constituted of Zn, P, Sn, As, Cr, Mg, Mn, Sb, Fe, Co, Al, Zr, Be, Ag, Pb, B, Ni, Si and Lanthanoide series elements and the balance Cu with inevitable impurities. This copper alloy is subjected to hot forging, is thereafter subjected to soln. treatment at >=600 deg.C, is subsequently cooled at >=1 deg.C/sec cooling rate, is thereafter subjected to cold working at >=20% draft and is subsequently subjected to aging treatment at 250 to 500 deg.C.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper alloy for plastic molds having particularly high strength and high thermal conductivity, and a method for producing the same.

0002

2. Description of the Related Art Steel materials and copper alloys are often used as materials for plastic molds, but mold materials with high thermal conductivity are required for the purpose of shortening the molding cycle time. The problems with these materials are that although steel materials have excellent high-temperature strength, they have low thermal conductivity, a large temperature gradient between the inside and outside of the mold, making the mold easily cracked, and a short lifespan. Further, although copper alloys have high thermal conductivity, they lack strength and therefore have the disadvantage of being easily deformed by compressive stress during plastic molding. It is possible to add metal elements to improve its strength, but
Generally, the addition of metal elements has the problem of lowering thermal conductivity and lengthening the molding cycle.

0003

[Problem to be solved by the invention] Therefore, the current challenge is how to shorten the molding cycle of products in order to improve productivity. High quality mold materials are desired.

Characteristic values required for materials for plastic molding molds are high strength, excellent high-temperature strength, and excellent thermal conductivity.

[0005] The present invention has been made in view of these points, and an object of the present invention is to provide a material that is easy to manufacture, has high strength and high temperature strength, and has excellent thermal conductivity.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the copper alloy for plastic molding molds according to the present invention contains Ti.
: Contains 1.0 to 4.0 wt%, and Zn, as subcomponents.
P, Sn, As, Cr, Mg, Mn, Sb, Fe, Co
, Al, Zr, Be, Ag, Pb, B, Ni, Si, and one or more of the lanthanoid elements.
．． 001 to 3.0 wt%, with the balance consisting of Cu and unavoidable impurities, and after hot forging, this copper alloy is subjected to solution treatment at 600°C or higher, and then cooled at 1°C/second or higher. After cooling at a speed of 20
% or more and then aging treatment at 250 to 500°C.

[0007] The copper alloy for plastic molds according to the present invention will be explained in detail below. Ti is an element that improves strength without reducing electrical conductivity because it precipitates in Cu by aging treatment after solution treatment.

[0008] The reason why the amount of Ti added is 1.0 to 4.0 wt% is because if it is less than 1.0 wt%, the required strength cannot be obtained, and the solid solubility limit of Ti in Cu is 4.3 wt%. , 4.0
If it contains more than wt% of Ti, solution treatment becomes virtually impossible, and the presence of coarse Cu3Ti grains makes it brittle and significantly degrades manufacturability. Therefore, the upper limit of the Ti content is set to 4.0 wt%.

In addition, Zn, P, Sn,
As, Cr, Mg, Mn, Sb, Fe, Co, Al, Z
r, Be, Ag, Pb, B, Ni, Si, and lanthanoid elements are elements that precipitate or form a solid solution in Cu and improve strength, but the amount added is 0.001 to 3.0 wt%.
The reason is that there is no effect if it is less than 0.001wt%,
On the other hand, if it exceeds 3.0 wt%, the strength will improve, but the conductivity will be significantly degraded and the manufacturability will also deteriorate.

Furthermore, the reason why the solution treatment temperature is set to 600° C. or higher is because solution treatment is insufficient at lower than 600° C., and a high-strength material cannot be obtained in the subsequent aging treatment. The subsequent cooling rate should be 1°C/sec or more.
This is because a cooling rate of less than a second causes a precipitation reaction of Ti, which deteriorates subsequent workability.

[0011] The reason why cold working is then performed at a working degree of 20% or more is to improve the strength, and if the working degree is less than 20%, the target hardness cannot be obtained. Also, 250
The reason for performing aging treatment at ~500°C is that it takes too much time to obtain the target strength at temperatures below 250°C, and when aging treatment is performed at temperatures above 500°C, the amount of Ti precipitated is small, making it difficult to obtain sufficient strength. This is because hardness and thermal conductivity cannot be obtained.

0012

[Example] Next, the results of evaluating the high-strength, high-thermal-conductivity copper alloy for plastic molding molds according to the present invention will be explained together with comparative alloys.

[0013] After hot forging the alloy having the components shown in Table 1,
The skin was shaved to a thickness of mm. Thereafter, solution treatment was performed as appropriate. After that, cold working was performed and aging treatment was performed.

Test pieces for tensile tests, Charpy impact tests and thermal conductivity measurements were taken from the material thus obtained. Table 1 shows the results of measuring the characteristic values of each alloy at room temperature and 300°C.

[0015]

[Table 1]

As is clear from Table 1, the alloy of the present invention has good high-temperature strength, thermal conductivity, and impact resistance, whereas the comparative alloy No. It can be seen that in No. 12, the solution treatment temperature was too low and sufficient strength could not be obtained, and the impact resistance was also low. Also No. No. 13 has a cooling rate that is too slow and similarly fails to provide sufficient strength and impact resistance. Similarly, No. No. 14 has a too low degree of cold working, so sufficient strength and impact resistance cannot be obtained. Furthermore, No. Since the aging temperature of No. 15 is low, sufficient strength and impact resistance cannot be obtained even after aging for as long as 10 hours. On the contrary, No. 16 is a solid solution of Ti because the aging temperature is too high.
There are too many and the thermal conductivity is low. Furthermore, No. In No. 17, sufficient strength and impact resistance cannot be obtained because the amount of Ti is small. Also N
o. In No. 18, the amount of Ti was too large, so cracks occurred during forging, and the characteristic values could not be evaluated. Furthermore, No. Sample No. 19 contained too many subcomponents, so the strength and impact resistance were sufficient, but the thermal conductivity was low.

[0017]

[Effects of the Invention] The alloy of the present invention described above has high strength, excellent high-temperature strength, excellent impact resistance, and high thermal conductivity, so the time required for plastic molding can be significantly shortened.
The expected effect of improving productivity is significant. Further, according to the production method of the present invention, a material for plastic molding molds that can be sufficiently solutionized, a material with high strength can be obtained by subsequent aging treatment, and has good workability can be obtained.
% or more, the target high hardness can be easily obtained. Furthermore, since the aging treatment is performed at 250 to 500°C, sufficient hardness and thermal conductivity can be obtained.

Claims (3)

[Claims] 1. A high-strength, high-thermal-conductivity copper alloy for plastic molding molds, which contains Ti: 1.0 to 4.0 wt%, with the remainder consisting of Cu and unavoidable impurities. [Claim 2] Contains Ti: 1.0 to 4.0 wt%, and Zn, P, Sn, As, Cr, Mg, M as subcomponents.
n, Sb, Fe, Co, Al, Zr, Be, Ag, Pb
, B, Ni, Si, one of the group consisting of lanthanoid elements
Contains 0.001 to 3.0 wt% of one or more species,
A high-strength, high-thermal-conductivity copper alloy for plastic molds, characterized in that the remainder consists of Cu and unavoidable impurities. 3. After hot forging, the copper alloy according to item 1 and item 2 is subjected to solution treatment at a temperature of 600°C or more, and then cooled at a cooling rate of 1°C/sec or more, and then the working degree is 2.
A method for producing a high-strength, high-thermal-conductivity copper alloy for plastic molds, which comprises performing cold working at 0% or more and then aging treatment at 250 to 500°C.