JPH04218629A - Copper alloy for metal mold for plastic molding - Google Patents

Abstract

PURPOSE:To provide a copper alloy for metal mold for plastic molding having superior manufacturability, increased in strength at high temp., and excellent in thermal conductivity. CONSTITUTION:The copper alloy is a copper alloy for metal mold for plastic molding characterized by having a composition consisting of, by weight, 1.5-3.0% Fe, 0.005-0.4% P, 0.001-2.0% of one or >=2 elements selected from the group consisting of Zn, Sn, Cr, Co, Ni, Ti, Zr, Si, Mg, Nb, and V as accessory components, and the balance Cu with inevitable impurities. Because this copper alloy as copper alloy for metal mold for plastic molding has superior strength at high temp., excellent impact resistance, and high thermal conductivity, the time required for plastic molding can be shortened remarkably and the improvement of productivity can be expected.

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 that has high strength and excellent thermal conductivity.

0002

BACKGROUND OF THE INVENTION Conventionally, iron-based alloys such as carbon steel for machine structures and steel for hot work tools have often been used as materials for plastic molds. Although these materials have excellent high-temperature strength, they have low thermal conductivity, resulting in a large temperature gradient between the inside and outside of the mold, making the mold easily cracked and having a short lifespan.

[0003] Also, as a material with high thermal conductivity, Cu
-Cr alloys are known, but are not widely used due to the low high temperature strength of the material.

However, the problem is how to shorten the molding cycle of products in order to improve productivity, and for this purpose there is a need for mold materials with high thermal conductivity.

[0005]

[Problems to be Solved by the Invention] Characteristic values required of materials for plastic molds are excellent high-temperature strength and excellent thermal conductivity. The present invention has been made in view of these points, and an object of the present invention is to provide a material for a plastic molding die that is easy to manufacture, has high 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 is made of Fe.
:1.5~3.0wt%, P:0.005~0.4wt
%, and Zn, Sn, Cr, Co, N as subcomponents.
1 of the group consisting of i, Ti, Zr, Si, Mg, Nb, V
Contains 0.001 to 2.0 wt% of one or more species,
It is characterized in that the remainder consists of Cu and unavoidable impurities.

[0007] The copper alloy for plastic molds according to the present invention will be explained in detail below. Fe is an element that improves strength without reducing conductivity because it precipitates in Cu alone or together with P as an intermetallic compound.

[0008] Furthermore, the amount of Fe added is 1.5 to 3.0 wt%.
This is because if it is less than 1.5 wt%, there is no effect of improving strength, and if it exceeds 3.0 wt%, thermal conductivity decreases and workability deteriorates.

Furthermore, P forms an intermetallic compound with Fe, but the addition amount is 0.005 to 0.4 wt% because
This is because if it is less than 0.005 wt%, there is almost no effect of improving strength, whereas if it exceeds 0.4 wt%, thermal conductivity decreases and workability deteriorates.

Furthermore, Zn, Sn,
Cr, Co, Ni, Ti, Zr, Si, Mg, Nb, V
0.001 to 2.0 of one or more of the group consisting of
The purpose of adding wt% is to further improve high-temperature strength, thermal conductivity, and impact resistance; if it is less than 0.001wt%, the effect cannot be expected, and if it exceeds 2.0wt%, the thermal conductivity will decrease. This is because the processability deteriorates.

[0011]

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

[0012] An ingot with a thickness of 100 mm was melted and cast in an inert atmosphere using an alloy having the components shown in Table 1, heated to 950°C and then hot-forged, and the forging end temperature was set to 700°C.
After having a thickness of m, it was cooled at a rate of 1° C./sec or more. This was then subjected to aging treatment at 450°C for 2 hours.

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.

[0014]

[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. No. 9 had low P and insufficient strength and impact resistance. Similarly, No. No. 10 has too much P and has low thermal conductivity. Also No. No. 11 has low Fe content and is insufficient in strength and impact resistance. Furthermore, No. No. 12 is a Cu-Cr alloy, but its impact resistance is low.

[0016]

Effects of the Invention The alloy of the present invention as described above is a very good copper alloy for plastic molds, and has excellent high-temperature strength and impact resistance. Furthermore, since it has high thermal conductivity, the time required for plastic molding can be significantly shortened and productivity can be expected to improve.

Claims (1)

[Claims] [Claim 1] Fe: 1.5 to 3.0 wt%, P: 0
．． 005 to 0.4 wt%, and Zn,
Sn, Cr, Co, Ni, Ti, Zr, Si, Mg, N
b, one or more of the group consisting of V from 0.001 to
A copper alloy for plastic molds, characterized in that it contains 2.0 wt%, and the remainder consists of Cu and unavoidable impurities.