JPH01309752A - Manufacture of high heat conductive complex die - Google Patents

Abstract

PURPOSE:To restrain deformation of a die, to improve the forming efficiency and to prevent the development of heat crack by heating and melting copper or copper alloy having high heat conductivity under non-oxidizing atmosphere and directly metal-joining with steel or cast iron at back surface of working face. CONSTITUTION:The die 1 containing the working face is produced with casting and oxide on the surface for executing joining is removed with mechanical or chemical treatment. Successively, after charging the copper or the copper alloy 2 having >=0.1cal/cm. deg.C.sec the heat conductivity, they are heated and melted under non-oxidizing atmosphere to directly join with the steel or the cast iron at the back surface of the working face. In this result, by making the heat conductivity in inner part of the die 1 high and cooling effect in the inner part large, unevenness of the temp. in the die is made small to restrain the deformation of the die, and also cycle time for forming products is shortened and the forming efficiency can be improved. Further, the development of the heat crack is restrained to improve the service life of the die.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a mold for casting molten metal, or a mold for molding molten plastic, molten glass, sand core, or the like.

[Conventional technology]

Conventional mold materials for applications that are used at high temperatures, such as molds for casting molten metal, molds for plastic/glass molding, and sand core molds, include steels such as hot die steel, stainless steel, cast iron, and metal molds. Copper alloys with higher thermal conductivity than these have been used as an integral part.

[Problem to be solved by the invention]

These molds take away the heat from the molten material to form it, which causes the mold to rise in temperature. However, in the case of molds made of N4 or cast iron, the level of thermal conductivity is not necessarily high, so the temperature of the mold increases. Depending on the shape or structure.

Large temperature irregularities occur within the mold, leading to mold deformation.
Furthermore, it was difficult to increase the number of molding cycles per unit time. In addition, copper alloys with high thermal conductivity also have low strength, so this problem has not been solved. The purpose of the present invention is to increase the thermal conductivity inside the mold and increase the internal cooling effect, thereby reducing temperature unevenness within the mold, suppressing mold deformation, and shortening the product molding cycle time. The present invention provides a method for manufacturing a highly thermally conductive composite mold that can improve molding efficiency, suppress the development of heat cracks, and improve mold life.

[Means to solve the problem]

The present invention provides a method for manufacturing a highly thermally conductive composite mold that solves the above problems. That is, the working surface of the mold is made of steel or cast iron, and the back surface of the working surface is made of copper or i
Jo, in a method for manufacturing a high thermal conductive composite mold that is directly metal-bonded with a copper alloy having a thermal conductivity of 1 cal/cm・℃・sec or more, the mold including the working surface is formed by cutting from a cast or forged product. After manufacturing and removing oxides on the surfaces to be joined by mechanical or chemical processing, copper or copper alloy is charged and then heated in a non-oxidizing atmosphere to melt the copper or copper alloy and join. Or, it is characterized by direct metal joining with cast iron.6 Also, after removing oxides from the joint surface, a metal brazing material and flux are interposed between the joint surface and the copper or copper alloy to be charged later. Alternatively, the copper alloy may be charged and then heated in a non-oxidizing atmosphere to melt the metal brazing material and join the steel or cast iron on the back side of the working surface and the copper or copper alloy inside through the brazing material. moreover.

When the copper alloy or copper alloy solidifies from the molten state, it is also possible to solidify the central part into a concave shape. As a means for solidifying this concave shape, a core made of ceramics, graphite, etc. that has low adhesion to the melt of the copper-based material is made into a convex shape corresponding to the desired concave shape, and then the copper or copper alloy is charged. Ceramics and graphite used in the core can be used in an integrated form or in a covered state.

Recesses formed on the copper or copper alloy surface remain as they are.

Alternatively, it can be machined and used as a water cooling structure to further improve the cooling effect of the entire composite mold.
It has the effect of preventing separation from the joint surface when copper or copper alloy solidifies and shrinks after melting.

The step of melting copper or copper alloy to the back surface of a mold made of steel or cast iron and directly metal bonding it, and the step of quenching the steel or cast iron can be performed in the same step. Furthermore,
Even if the process of melting a metal brazing metal on the back side of a mold made of steel or cast iron and joining the copper or copper alloy inside through the brazing metal and the quenching process of the steel or cast iron are performed in the same process. good.

In order for the steel on the working surface of the mold to have appropriate properties, the weight ratio must be C0.1-1.1%, Si≦3.00%, Mn≦3.
00%, Ni≦4.00%, Cr≦18.00%, W and Mo alone or in combination (1/2W+Mo)512
．． 00%, and further V≦3.00%%Go≦6.
5%, Al≦1.50%, Cu≦3.00%, and the balance is preferably substantially Fe.

〔Example〕

A detailed explanation will be given below based on examples.

Example 1 After forging and drawing a 60 mφ forged material of 5KD61, a 40+m+φ hole was machined into a cup shape to produce a mold including a working surface.

A composite mold was produced using the cup-shaped mold according to the conditions shown in Table 1. Copper alloy 1 shown in Table 1 is Ni-9i, which the present inventor has already proposed as a material with excellent thermal conductivity and suitable strength as a mold (Japanese Patent Application Laid-Open No. 133357/1982). Precipitation strengthened copper alloy, copper alloy 2 is 6
0/40 brass, copper alloy 3 is 70/30 brass. Their thermal conductivities are shown in Table 2. Here, three examples of copper alloys used are shown.

Generally, the level of thermal conductivity of steel materials used for molds is less than the thermal conductivity * 0.1 cal/cm・℃・sec.

By using the same alloy with a thermal conductivity higher than this, the thermal conductivity of the mold will be increased, and it will be 0.1 cal/
Any type of copper alloy is effective as long as it has a thermal conductivity of cm/°C/sec or higher.

Table 2 In addition, when a metal brazing material is used, a flux-coated welding rod of a metal brazing material (material: Cu-Zn alloy) is used to join the mold including the working surface using the three methods shown in Figure 1. attached to the surface. Figure 1(a) shows a method of heating the welding rod with a burner, melting it, and attaching it to the inner wall.
b) is a method in which the welding rod is cut to an appropriate size and placed along the inner wall. In FIG. 1(c), the metal brazing material and flux were attached while heating the bonding surface so as to uniformly adhere the metal brazing material and flux to the bonding surface in the same manner as in FIG. 1(a).

As shown in Table 1, except for samples No. 61, No. 10, the state of metallurgical bonding between the 5KD61 mold including the working surface and the charged copper or copper alloy was good. Figures 2 and 3 show sample No. 3 and sample No. 5.
Line analysis of each element was performed by scanning the microstructure of the joint and the joint with characteristic X-rays.

It is clear that the steel diffuses to the 5KD61 side and is sufficiently bonded.

Samples No. 1 and No. 10 are 5KD molds including the working surface.
The bonding surfaces of 61 and copper or copper alloy are oxidized, resulting in insufficient bonding. In samples No. 1, oxidation was severe when heated in the atmosphere, and in sample No. 10, 5K was generated when the welding rod of brazing metal was turned into droplets by heating with a burner.
The bonding surface of D61 was heated and oxidized, resulting in poor bonding.

Example 2 Inner dimensions are width 120wm, length 160I, height 45+n
The mold was made of steel 5KD61 and cast iron Fe1, with a bottom of
2 was cast into a box shape. A composite mold was manufactured under the conditions shown in Table 3. In addition, FIG. 4 shows the method of charging the charge and the core.

Table 3 As shown in Table 3, except for samples No. 11 and 13, the bonding state between the mold including the working surface and the charged copper or copper alloy 1 was good.

In sample No. 11, the mold including the working surface was oxidized during casting, and the joining surface was covered with an oxide film. Therefore, the oxide film was removed by sandblasting or pickling without joining. The bonding conditions of No. 12, 14, and 15 were improved and good.

In No. 13, the mold including the working surface and the charged copper were partially peeled off. This is because the coefficient of thermal expansion of copper is larger than the 5KD61 of the mold including the working surface, so the copper shrinks more during the cooling process after heating, and as shown in Figure 4, an alumina core is placed in the center. N o , 1・2.1
4.15 showed a good bonding state.

Example 3 Next, an application example of the mold produced by the method of the present invention will be described.

Table 4 shows examples of reduction in molding cycle time when the mold according to the present invention is applied to a glass-containing plastic mold.

The fourth table mold has inner dimensions of 300 m in diameter and 400 m in height + (wall thickness of 100 m).The mold of the present invention has a surface layer of SKD12 (I
C-5Cr-IMo-0.4V) with a hardness of HRC55 and a thickness of 8 nn, and the back side of the mold was composited with copper alloy 2 shown in Table 1.

This was compared with the conventional 5KD12 case. For reference, the results of a test made by manufacturing one mold using Copper Alloy 2 in Table 1 are also shown.

In the case of the alloy of the present invention, the molding cycle time was halved. In addition, in the case of the one-piece type of copper alloy 2, as shown in Table 4, abrasion progressed easily and the lifespan was shortened.

Table 5 shows the state of melting loss and heat cracking when the mold according to the present invention is applied to a pressure die casting mold.

The working surface of the mold is 5KD61100 x 150 x 8
0nn+ (wall thickness: 60 m) at 700° C.] Alloy was injected under pressure and the working surface was cooled with water after molding, and the number of 5 hots until gate melting and heat cracking occurred was determined.

The mold of the present invention has a working surface of 5KD61 (HRC4
5), the thickness of 5KD61 is 8 m or less, and pure copper is composited on the back side.

Table 5 In the case of the present invention type, results were obtained in which the corrosion resistance and heat crack resistance life were significantly improved.

Example 4 The working surface of the mold was 0.28% G and 0.28% Si by weight.
60%, Mn 0.21%, Ni 0.85%, Cr
14.51%, WO08%, Mo1.2%, 76.3%
, Co 4.56%, and the balance substantially Fe is machined into a cup shape with the dimensions of the working surface of the mold (diameter 150 m, height 10100 l, wall thickness 10 m), and then copper is placed inside the cup shape. A composite mold was created by melting the materials and directly metal-bonding them. Using this composite mold as a glass mold, the corrosion status of the surface portion and the number of 5 hots until the occurrence of heat cracks were determined and are shown in Table 6. As a comparison material, an integral mold made from conventional steel 5US420J and having the same outer diameter was used.

Table 6 In the case of the inventive type, compared to conventional steel, the life of the mold was significantly improved due to the effect of preventing the temperature rise of the mold working surface and the effect of improving corrosion resistance and high temperature strength due to the composition.

Example 5 The working surface of the mold was 0.27% C, 0.6% Si by weight.
3%, Mn 0.19%, Ni 0.82%, Cr 1
4.75%, W 0.7%.

A steel consisting of Mo 1.3%, V 6.1%, Co 4.32%, and the balance substantially Fe was made with a mold working surface dimension of 100%.
After machining into a box shape of x 150 x 80 m (thickness: 6 m), a composite mold was produced by melting copper alloy 1 inside the box-shaped mold and directly metal-bonding it. Table 7 shows the results of molding two plastics using this composite mold and examining the state of corrosion on their surfaces. In addition, as a comparison steel, conventional steel 5US4
An integral mold made from 20J2 and having the same external dimensions was used.

Table 7 × Comparison after 200 shots In the case of the mold of the present invention, the mold surface after 200 shots is not recognized as corroded, but has a cloudy surface in two parts, whereas in the case of conventional steel, The entire surface was cloudy, and spotty corrosion was observed on other parts of the skin.

Example 6 The working surface of the mold has a weight percentage of 1,03% Si, 0
．． 33%, Mn 0.57%, Ni 0.65%,
C, r 7.23%, Mo 1.32%, V 1.8
The dimensions of the working surface of the mold are 60IIW11 in outer diameter, 40ngo in inner diameter, and 40W in height.
After machined into a cup shape with a thickness of n (bottom thickness 8 rrrs), weld the joint surface of the mold using the method shown in Fig. 1(a) using a flux-coated Cu-Zn alloy solder metal welding rod. A composite mold was prepared in which the copper alloy 2 was attached and bonded by charging the copper alloy 2. This composite mold was used for sand core firing, and the amount of wear after 150 shots was compared, and the results are shown in Table 8. In addition, as a comparison steel, conventional steel FC
An integrated type having the same shape and made from No. 30 was used.

Table 8 As shown in Table 8, it can be seen that the mold of the present invention has extremely excellent wear resistance.

Example 7 The working surface of the mold was % by weight, C082%, SLo, 38%
, Mn 0.30%, Ni 3.52%, Mo 2.
Using a composite mold made of steel consisting of 86% and the remainder substantially Fe in the same manner as in Example 3,
An Al alloy was molded under the same molding conditions. The results are shown in Table 9, partially overlapping the results obtained in Example 3.

Table 9 In the case of the mold of the present invention, 5KD for the integrated type of 5KD61
When 61 was used as a work surface steel and used as a composite mold, the life of the mold was significantly improved, and even more remarkable effects were obtained in the case of a composite mold having the above composition.

Example 8 The working surface of the mold was 0.14% G, 0.2% Si by weight.
5%, Mn0.79%, Ni 3.01%, Mo0.4
1%, At 1.27%, Cu 2.30%, and the balance substantially Fe, the dimensions of the working surface of the mold are 150
After machining into a box shape of 160 x 70+nm (thickness 6+nm), a composite mold was produced by melting copper alloy 2 inside the box-shaped mold and directly metal-bonding it. Plastics were molded using this composite mold and the wear conditions of the surface portions were compared, and the results are shown in Table 10. In addition, conventional m Cr-M is used as a comparison steel.

An integral type made of steel and having the same shape was used.

Table 10 In the mold of the present invention, an extremely large improvement was observed due to the high initial hardness of the mold surface in addition to the cooling effect of the composite mold.

〔Effect of the invention〕

As described above, the high thermal conductivity composite mold produced by the manufacturing method of the present invention has superior thermal conductivity compared to conventional materials,
Low-pressure Al casting, Fe-based material casting mold materials, Al-based and Cu
It dramatically improves molding efficiency for pressure die casting of alloys, gravity casting molds, sand core firing molds, and plastic molds, and also prevents problems such as mold warping, cracking due to heat cracks, melting damage, and wear. This method solves the problem and has a significant industrial effect.

[Brief explanation of the drawing]

Figure 1 shows the method of attaching brazing filler metal to the back side of the mold, including the first working surface. Figures 2 and 3 show photographs of the micrometallic structure of the joint and the state of diffusion of elements. Alloy charging situation and core installation situation Fig. 1 3 Hardware No. 2 Fig. 3 Fig. 5 Ko6+! Can type 2 including the 4th figure 1 and the 1st part of the construction.

Claims (1)

[Claims] 1. The working surface of the mold is made of steel or cast iron, and the back surface of the working surface is directly metal-bonded with copper or a copper alloy having a thermal conductivity of 0.1 cal/cm・℃・sec or more. In the method for manufacturing a composite mold with high thermal conductivity, a mold including a working surface is produced by casting, oxides on the surface to be joined are removed by mechanical treatment or chemical treatment, and then copper or copper alloy is mounted. A method for producing a composite mold with high thermal conductivity, which comprises heating the mold in a non-oxidizing atmosphere to melt the copper or copper alloy and directly metallize it with the steel or cast iron on the back side of the working surface. 2. A highly thermally conductive composite mold in which the working surface of the mold is made of steel, and the back surface of the working surface is directly metal-bonded with copper or a copper alloy having a thermal conductivity of 0.1 cal/cm・℃・sec or more. In the manufacturing method, a mold including the working surface is made by cutting from a forged product, oxides on the surface to be joined are removed by mechanical or chemical treatment, and then copper or copper alloy is charged. A method for manufacturing a composite mold with high thermal conductivity, which is characterized by heating in a non-oxidizing atmosphere to melt copper or copper alloy and directly metal joining it to steel on the back side of the working surface. 3. The method according to any one of claims 1 and 2, wherein after removing oxides on the joint surface, flux is applied to the joint surface or after the flux is spread, copper or copper alloy is charged. A method for manufacturing a composite mold with high thermal conductivity. 4 The working surface of the mold is made of steel or cast iron, and the back surface of the working surface is a high-temperature mold that is bonded to copper or a copper alloy having a thermal conductivity of 0.1 cal/cm・℃・sec or more via a metal brazing material. In a method for manufacturing a conductive composite mold, a mold including a working surface is produced by casting, oxides on the surface to be joined are removed by mechanical treatment or chemical treatment, and then the mold is charged later with the joint surface. A metal brazing material and flux are interposed between the copper or copper alloy, and the copper or copper alloy is charged and then heated in a non-oxidizing atmosphere to melt the metal brazing material and connect it to the steel or cast iron on the back side of the work surface. A method for manufacturing a highly thermally conductive composite mold, characterized by joining copper or copper alloys through a brazing material. 5 A high thermal conductivity mold in which the working surface of the mold is made of steel, and the back surface of the working surface is joined to copper or a copper alloy having a thermal conductivity of 0.1 cal/cm・℃・sec or more via a metal brazing material. In the manufacturing method of composite molds, a mold including a working surface is produced by cutting from a forged product, and after removing oxides on the surfaces to be joined by mechanical or chemical treatment, the joining surfaces and later mounting are removed. A metal brazing material and a flux are interposed between the copper or copper alloy, and the copper or copper alloy is charged and then heated in a non-oxidizing atmosphere to melt the metal brazing material and bond it to the steel on the back side of the work surface. A method for manufacturing a highly thermally conductive composite mold, characterized by joining copper or copper alloys through a brazing material. 6. The method for manufacturing a highly thermally conductive composite mold according to any one of claims 1 to 5, wherein the mechanical removal of the oxide on the joint surface is performed by sandblasting. 7. The method for manufacturing a highly thermally conductive composite mold according to any one of claims 1 to 5, wherein the removal of oxides on the joint surface by chemical treatment is carried out by pickling. 8. A method for manufacturing a highly thermally conductive composite mold according to any one of claims 1 to 3, in which a concave portion is formed in the center when copper or copper alloy solidifies from a molten state. . 9. The highly thermally conductive composite metal according to claim 8, in which a ceramic or graphite core is placed in the center of the charged copper or copper alloy as a means for forming the concave portion, and then heated and melted to solidify. Mold manufacturing method. 10. Claim 1, characterized in that the step of melting copper or copper alloy to the back side of a mold made of steel or cast iron and directly metal-bonding it, and the step of quenching the steel or cast iron are performed in the same step. A method for manufacturing a highly thermally conductive composite mold according to any one of Items 1 to 3 or 6 to 9. 11. The process of melting a metal brazing material on the back side of a mold made of steel or cast iron and joining the copper or copper alloy inside through the brazing material and the quenching process of the steel or cast iron are performed in the same process. A method for manufacturing a highly thermally conductive composite mold according to any one of claims 4 to 7, characterized in that: 12 The steel on the working surface of the mold has a C0.1-1.1% weight ratio.
, Si≦2.00%, Mn≦2.00%, Ni≦4.0
0%, Cr≦18.00%, W and Mo alone or in combination (1/2W+Mo)≦12.00%, further V≦3.00%, Co≦6.5%, Al≦1 .50
%, contains one or more types of Cu≦3.00%, the remainder is real F
12. The method for manufacturing a highly thermally conductive composite mold according to any one of claims 1 to 11, characterized in that the mold comprises: e.