JPH0340099B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a mold material for molding parts with complex shapes, and is particularly used as a powder injection mold for plastics, rubber, metals, ceramics, etc. This invention relates to aluminum alloy materials. [Prior Art] Steel materials are generally used for plastic injection molding molds and blow molding molds. However, aluminum alloys are used for molds that do not require mass production. Aluminum alloy molds have a short mold life because they are inferior in wear resistance, softening resistance, and high-temperature strength compared to steel materials, but they have been preferred because they have the following advantages. Due to good machinability, mold drilling speed is fast,
Mold production time is short. It also has a long tool life during machining. Due to its low specific gravity, it is easy to handle in mold production and installation. Due to its good corrosion resistance, maintenance during suspension is easy. Due to its high thermal conductivity, it has a high cooling capacity as a mold and can shorten the molding cycle. The types of aluminum alloys require strength, so JIS alloys include Al-Zn-Mg- such as 7075 and 7079.
Cu alloys have been used. As mentioned above, aluminum alloy molds use an aluminum alloy that has excellent strength and wear resistance, but the mold life is short compared to steel materials. For example, a steel material mold can punch more than 100,000 shots, but an aluminum alloy mold can punch only 3,000 to 5,000 shots. For this reason, aluminum alloy molds have only been used as simple molds with short lifespans. In addition, there was a difference in mold life of about 30 times between steel materials and aluminum alloys, making it impossible to take advantage of the superiority of aluminum alloy molds. 1/ of steel with aluminum alloy
It was hoped that something with a lifespan of 10 or more would be developed. [Problem to be solved by the invention] The present invention has been made in view of these circumstances.
The purpose of this invention is to provide an aluminum alloy mold material that has a lifespan of approximately 1/10 or more of that of steel molds. [Means for Solving the Problems] In order to solve the above problems, the strength, wear resistance, machinability (surface As a result of studying the effects on roughness, etc., we found that at least Si and Cu are contained as alloy components in Al alloys formed by powder forming.
In addition, they discovered that it is effective to maintain the particle size of Si within a specific range, and completed the present invention. That is, the first invention has Si17 to 30% by weight,
An aluminum alloy obtained by powder compaction with a composition containing 0.5 to 10% Cu and the remainder Al and unavoidable impurities, and characterized in that the average diameter of Si particles is 0.3 to 10 μm. It is an aluminum alloy material. The second invention is Si17 to 30% and Cu0.5 to 10% by weight.
%, Mg 0.3 to 6%, and the balance is Al and inevitable impurities, and the average particle size of the Si particles is 0.3 to 10 μm. It is an aluminum alloy material characterized by: The third invention is in weight%
Contains 17~30% Si, 0.5~10% Cu, and further Fe,
Aluminum obtained by powder compaction containing 0.3 to 6% of one or more metals selected from the group consisting of Mn and Ni, singly or in total, with the balance consisting of Al and unavoidable impurities. The aluminum alloy material is an alloy and is characterized in that the average diameter of Si and its compound particles is 0.3 to 10 μm. Furthermore, the fourth invention is Si17 to 30% by weight,
Contains Cu0.5-10%, Mg0.3-6%, and
A metal selected from the group consisting of Fe, Mn and Ni
An aluminum alloy obtained by powder compaction containing one or more species alone or in total of 0.3 to 6%, with the balance consisting of Al and inevitable impurities, and the average diameter of Si and its compound particles. It is an aluminum alloy material characterized by having a diameter of 0.3 to 10 μm. Next, the reasons for limiting the composition of the aluminum alloy of the present invention will be described. Si is dispersed as Si particles in the Al base and increases wear resistance. In addition, the thermal expansion coefficient is lowered to suppress distortion caused by heat generation during machining, and the elastic modulus is increased to suppress distortion caused by chuck during processing. If Si is less than 15%, wear resistance will be insufficient, and if it exceeds 40%, chipping and wear of the machining tool will easily occur, and the surface roughness of the machined surface will become rough.
A range of 40% is effective, but depending on the balance between the two parties17
It is preferable to contain up to 30%. Cu imparts age hardenability to the alloy and improves wear resistance due to improved hardness. Cu 0.5%
If it is less than 10%, the effect will not be sufficient, and if it exceeds 10%, the effect will be saturated and the corrosion resistance will deteriorate significantly.
It was set at 0.5-10%. Also, in cooperation with both parties, 1
~6% is more preferred. Mg coexists with Cu and improves hardness and wear resistance through age hardening. If Mg is less than 0.3%, the effect will not be sufficient, and if it exceeds 6%, the effect will be saturated, so it was set at 0.3 to 6%. Further, from the viewpoint of mold life, it is more preferable that the content is 0.5% or more. Each component of Fe, Mn, and Ni increases the heat resistance of the alloy. That is, the temperature during mold use (e.g. 100
~150℃), suppresses the decrease in hardness (softening),
It also increases the strength at room temperature to high temperature. Furthermore, it has the effect of lowering the coefficient of thermal expansion and increasing the modulus of elasticity. If the content of these components is less than 0.3% individually or in total, the effect will not be sufficient, and if the content exceeds 6%, the material will become brittle and easily chipped during mold processing or use. In addition, if the average diameter of particles of Si and its intermetallic compounds is less than 0.3 μm, wear resistance will be insufficient;
If it exceeds the limit, chipping and wear of the machining tool will easily occur, and the surface roughness of the machined surface will become rough. In the present invention, the Si particles include both primary and eutectic particles. Although there are various methods for producing the aluminum alloy of the present invention, it is generally produced by the following method.
That is, after melting the aluminum alloy having the above-mentioned composition, the molten metal is rapidly solidified. Usually 100℃/
Cooled at a cooling rate of seconds or more. Specifically, the atomization method and the splattering method are applied.
The powder thus obtained is subjected to (a) pre-compression - filling in a container - heating vacuum degassing - extrusion, (b) pre-compression - filling in a container - heating vacuum degassing - hot press, (c) pre-compression - filling in a container - heating vacuum degassing. -Hot press-container removal-
Extrusion, (d) Pre-compression-Heating-Extrusion, (c) Pre-compression
It is solidified and molded through processes such as filling a container, heating vacuum degassing, and HIP (high temperature isostatic pressure). in particular
In method (a), aluminum alloy powder is pre-compressed to about 60-90% of its true density by CIP or mold compression, then sealed in a designated container, heated to 300-550°C, evacuated, and degassed. I do. If the heating temperature during degassing is less than 300°C, degassing will be insufficient and the final product will swell or have pores. When the temperature exceeds 550℃, Si particles grow and become coarse.
The pre-compressed product (billet) thus degassed is heated to a temperature of 300 to 520°C and extruded. In method (b), the aluminum alloy material is made by hot pressing (upsetting and compacting at high temperature) instead of extrusion, (c) is the method in which the container is cut and removed after hot pressing, and (d) is the preparatory material. In air after compression,
In the case of (c), the aluminum alloy material is obtained by HIP treatment instead of _extrusion or hot pressing. When the size of the mold is large and a large-sized material is required, the material is solidified by any of the above processes, especially (b) hot pressing or HIP, and then expanded by forging or rolling to create a large-sized material. . The alloy material manufactured in this way has properties such as superior wear resistance, strength, hardness, and heat resistance, low coefficient of thermal expansion, and high modulus of elasticity compared to conventional aluminum alloy materials for molds, and is suitable for molds. It is ideal as a material. In addition, the thermal conductivity is almost the same as that of 7075 alloy, so the life of machining tools will not be shortened. Electric discharge machining is also possible. Furthermore, alumite treatment is also possible. This treatment is performed to further increase wear resistance, and hard alumite is usually used. In addition, if the design of the mold is changed, or if deep engraving is performed by mistake, it is also possible to build up the material by welding. TIG, MIG, etc. are also possible welding methods, but
If possible, electron beam welding or plasma arc welding, which can reduce the welding area, is preferable. Filler rods include BA4043, BA4045, BA4145,
BA4047, BA4003, BA4004, BA4005,
BA4N04 etc. are used. In addition, when welding, increase the degassing temperature or lengthen the degassing time during solidification and molding of the powder, and reduce the amount of hydrogen in the material to 0.5cc/100gAl or less, preferably 0.3cc/100gAl.
It is preferable to set it to less than gAl. At this time, the degassing temperature is
It is desirable to set it as 490-550 degrees Celsius. Example 1 The present invention will be described in further detail with reference to Examples below. Alloys No. 1 to No. 29 shown in Table 1 were melted and rapidly solidified powder was created by air atomization. The obtained powder was classified to a particle size of 297 μm or less, and then pre-compressed to 70 to 75% of the true density by CIP, inserted into an Al container, and vacuum degassed while being heated. The heating temperature was 500°C. However, only No. 18 was degassed while being heated at 550°C in order to grow Si particles. The billet thus obtained was heated to 390°C and extruded at an extrusion ratio of 14 to obtain a rod with an outer diameter of 40 mm. These extruded rods No. 1 to No. 18 were subjected to heat treatment at 500°C for 2 hours, water cooling, and 175°C for 8 hours. Alloy No. 30 in Table 1 has the same composition as No. 29, but after melting to make the Si particles fine, a ribbon-shaped rapidly solidified material was obtained by a single roll method. After that, it was molded in the same manner as above. However, in order to suppress the growth of Si particles, the heating temperature during degassing was set to 450°C. After melting the alloy No. 31 in Table 1, an ingot with an outer diameter of 150 mm was prepared, and this was extruded under the same conditions as above. About the extrusion rod 470℃ x 2hr → water cooling → 115℃ x 7hr → 175
Heat treatment (T73 treatment) was performed at ℃×8 hours. Regarding the above materials, the particle size in the microstructure (Si particles, Al-Si-Fe compound particles, Al-Si
- Average diameter of all particles such as Mn-based compound particles and Al-Ni-based compound particles), hardness at room temperature (Rockwell B scale), hardness at room temperature after heating to 150°C (Rockwell B scale), tensile strength at room temperature, at 150℃
Measurement of tensile strength at 150℃ after holding for 100 hours, specific wear amount in Okoshi type wear test (dry type, load 2.1Kg, friction distance 600m, mating material S50C), and surface roughness (R _nax ) after buffing. did. The results are shown in Table 2. Invention alloy No. 1~
In the case of No. 18, the specific wear amount is small, especially 7075 (No. 33)
significantly smaller. In addition, the surface roughness is as small as 7075, and the surface finish is good. Also, No.
Among No. 1 to No. 18, No. 1 and No. 2 do not contain Mg.
Comparing No. 3 and No. 4 containing Mg, it is shown that the hardness tends to increase with the addition of Mg.
No. 5 to No. 18 containing Mn and/or Ni are No. 1 to No.
It can be seen that the hardness after heating and the tensile strength at 150°C are higher than No. 4. Comparative alloy No. 19 has a large specific wear amount because of a small amount of Si, and No. 20 has a large amount of Si and has a large surface roughness. No. 21 has a low hardness due to the small amount of Cu, and has a large specific wear amount. No. 22 and No. 23 have increased amounts of Cu and Mg, but their effects are not apparent (the effects are saturated). No.24-28 are Fe,
Since the amounts of Mn and Ni are too large individually or in combination, chipping is likely to occur during processing of the mold. No.29
has a large particle size and therefore has a large surface roughness. No.
30 does not have sufficient wear resistance due to its small particle size.

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[Table] [Effects of the Invention] (1) As explained above, the aluminum alloy material of the present invention has the machinability, lightness, corrosion resistance, thermal conductivity, and surface treatability (anodizing property) that aluminum alloys have. It has improved wear resistance and heat resistance without sacrificing advantages such as weldability, making it suitable for molds for molding plastics, rubber, metal powders, ceramic powders, etc., and significantly improving its service life. I can do it.

[Brief explanation of drawings]

FIG. 1 is a plan view of the part molded in Example 2, FIG. 2 is a side sectional view of the same, and FIG. 3 is a perspective view of the same.

Claims (1)

[Claims] Contains 17 to 30% Si and 0.5 to 10% Cu at 1% by weight,
A plastic molded metal with excellent wear resistance, which is an aluminum alloy obtained by powder molding with a composition consisting of the balance Al and unavoidable impurities, and the average diameter of Si particles is 0.3 to 10 μm. Aluminum alloy material for mold. 2 Weight%: Si17-30%, Cu0.5-10%, Mg0.3
~6%, with the balance consisting of Al and unavoidable impurities, and the average diameter of the Si particles is
An aluminum alloy material for plastic molds with excellent wear resistance characterized by a thickness of 0.3 to 10 μm. 3 Contains 17 to 30% Si and 0.5 to 10% Cu by weight,
Furthermore, one or more metals selected from the group consisting of Fe, Mn, and Ni are added individually and in total to 0.3
An aluminum alloy obtained by powder compaction with a composition of ~6% and the remainder consisting of Al and unavoidable impurities, and characterized in that the average diameter of Si and its compound particles is 0.3 to 10 μm. Aluminum alloy material for plastic molds with excellent wear resistance and heat resistance. 4 Weight%: Si17-30%, Cu0.5-10%, Mg0.3
6%, and further contains 0.3 to 6% of one or more metals selected from the group consisting of Fe, Mn, and Ni, individually and in total, with the balance consisting of Al and inevitable impurities. An aluminum alloy for plastic molds having excellent wear resistance and heat resistance, which is obtained by powder compaction of material.