JPH0818063B2 - Manufacturing method of vacuum clad material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a vacuum clad material made of a metal material such as aluminum used as a vacuum material.

2. Description of the Related Art As a method for producing a clad material of this type, for example, a clad pipe, a method in which a hollow composite billet having two inner and outer layers is used and a mandrel type extrusion is performed on the hollow composite billet has been generally used. Are known. As shown in FIG. 4, the composite billet conventionally used in this method has a hollow core billet (53) whose outer diameter is constant in the longitudinal direction and an inner diameter which is constant in the longitudinal direction. The core billet (53) and the skin material billet (52) are formed by combination with the hollow skin material billet (52) by shrink fitting the inner peripheral surface of the skin material billet (52). Billet for core (5
It was supposed to be compounded by a method such as crimping to the outer peripheral surface of 3).

However, when the composite billet (51) is manufactured by shrinkage fitting, air is generated between the outer peripheral surface of the core material billet (53) and the inner peripheral surface of the skin material billet (52). There is a high possibility of being trapped, and when extrusion is performed using such a composite billet (51) containing air, the obtained clad pipe may have defects such as blisters. Therefore, when such a clad pipe is used as a vacuum material, air trapped between the core material and the skin material, blisters, or the like leaks out, which may adversely affect the degree of vacuum arrival.

Further, when extrusion is performed using such a composite billet (51), the metal on the center side of the billet generally tends to flow faster than the metal on the outer periphery in extrusion, so the obtained clad pipe is The inner layer is extremely thick at the front end portion and gradually thins as it moves to the rear end side, and it does not exist at all from the central portion to the rear end portion, and has the inner layer evenly in the length direction. It was difficult to manufacture a clad pipe. Such a defect similarly occurs not only in the clad pipe but also in a solid clad material obtained by using a solid composite billet and extruding the inner billet material as a core.

The present invention solves the above-mentioned problems with the conventional ones and can prevent the occurrence of defects such as blisters in the obtained clad material, and at the same time, the thickness of the skin material and the core material is a uniform vacuum in the length direction. An object of the present invention is to provide a method for manufacturing a clad material for use.

Means for Solving the Problems In order to achieve the above object, the present invention is directed to a core material in which an outer peripheral surface is formed into a conical tapered surface having an increased cross-sectional area from a die side end to a stem side end. A billet and a hollow skin material billet having an inner peripheral surface formed into a conical taper surface corresponding to the taper surface are cleaned by performing an immersion cleaning treatment on the both taper surfaces, and then mutually. While press-fitting, the die side joint end and stem side joint end of both billets are welded over their entire circumference to create a composite billet, and this composite billet is extruded from the die side end. The gist is a method of manufacturing a vacuum clad material, which is characterized in that.

Action By subjecting the billet for core material and the billet for skin material to the immersion cleaning treatment, oil, dust, dirt and the like attached to the tapered surface of the billet during the cutting process are completely removed.
Then, in the process of press-fitting both billets that have been cleaned in this way, the air present between the billet materials will be discharged and removed to either end side due to the ± tolerance of the tapered surfaces. , Air is not trapped between both billets. Moreover, since the die side end joint portion and the stem side joint portion of both billets press-fitted with the air completely eliminated are welded over the entire circumference, such a composite billet The exfoliation of the inner and outer billets and the entrainment of air during the extrusion are completely prevented, and defects such as blisters do not occur in the resulting clad material.

Moreover, the cross-sectional area of the core material billet, in which the speed of metal flow in extrusion is relatively faster than that of the skin material billet, is such that the outer peripheral surface of the billet for the core material is a conical taper surface, so that Since it is small and large at the end on the stem side, the amount of metal extruded from the core material billet is equalized throughout the extrusion process, and the obtained clad material is a uniform skin material and core material in the longitudinal direction. Will have.

Embodiment Hereinafter, the present invention will be described based on illustrated embodiments.

In FIG. 1, (1) is a composite billet, which comprises a combination of a core material billet material (2) and a skin material outer billet (3).

The core material billet (3) is formed into a hollow shape having a mandrel insertion hole (6),
Its inner diameter is made constant over its entire length and its outer peripheral surface is formed into a conical taper surface (5), so that it traverses from the die side end (7) toward the stem side end (8). The area is said to have been increased.

On the other hand, the skin material billet (2) is formed in a hollow shape, and the outer peripheral surface is in contact with the inner surface of the container so that the outer diameter is constant over the entire length and the inner peripheral surface is for the core material. By forming the conical tapered surface (4) corresponding to the tapered surface (5) of the billet (3), the cross-sectional area from the die side end (7) to the stem side end (8) is reduced. It is said to have been reduced.

To form a composite of both billets (2) and (3), the core material billet (3) is press-fitted into the hollow of the skin material billet (2), and both tapered surfaces (4) and (5) are brought into a pressure contact state. To be achieved. As shown in FIG. 3, both the tapered surfaces (4)
The air present between (5) is tapered surface (4).
Due to the ± tolerance of the inclination of (5), it will be discharged and removed to either side (in the case of the same figure, the direction of arrow (A)), and air will be tapered surface (4) (5) in the pressure contact state.
You will not be trapped between them. However, if oil, dust, dirt, etc. are attached to the surfaces of the above-mentioned tapered surfaces during cutting, air will be trapped between them. Therefore, it is necessary to completely clean both the tapered surfaces before the above-mentioned compounding. For such cleaning, wiping with a thinner or the like is not sufficient, and a dipping cleaning treatment such as caustic cleaning is performed.

The clad material is manufactured as a clad pipe by using the above composite billet (1) and performing extrusion by a mandrel method with the die side end portion (7) directed in the extrusion direction (arrow E in FIG. 1). It

The degree of inclination of the taper surface (5) is appropriately determined in consideration of the material of the billet (2) (3) for inner skin material, and the taper degree T is In general, the value of T is preferably set in the range of 1/30 to 1/60, for example, about 1/50, whereby the clad having the inner layer uniformly in the length direction. It becomes possible to manufacture wood.

Here, the outer diameter is 112 mm, the inner diameter is 98 mm, and the inner layer thickness is 2 mm.
The following was prepared as an extrusion composite billet (1) in order to produce the clad pipe.

As the core billet (3), one made of A6063 alloy having an inner diameter Di of 140 mm, an outer diameter Dd of the die side end (7) of 190 mm, and an outer diameter Ds of the stem side end (8) of 200 mm is used. , The outer diameter D _{0 of the} billet for leather (2) is 30
Use a 5 mm pure aluminum product with a purity of 99.99%. Both billets (2) and (3) have a concentration of 5 wt% and a liquid temperature of 40 ° C.
After dipping for 60 seconds in the aqueous sodium hydroxide solution, and then subjecting it to a neutralizing treatment, washing with water, and caustic washing treatment of drying,
Both billets (2) and (3) are press-fitted with a pressure of 100 tons, and then the die side joint end and the stem side joint end of both billets are welded over the entire circumference thereof to form a composite billet ( 1) was produced. In the figure, (9) indicates a welded portion.

And using this billet (1), the billet temperature is 480
Under the extrusion conditions of ℃, ram speed 3.0 mm / sec, and product speed 5.0 m / min, the mandrel system extrusion was performed, and the total length was 12 m, and the inner layer was present from the front end to the rear end, and A clad pipe with a thickness of 2 mm was obtained over the entire length. Moreover, there were no defects such as blisters.

In the present invention, the core billet may be solid to form a composite billet, and the composite billet may be extruded as a solid clad material.

EFFECTS OF THE INVENTION Depending on the above, the method for producing a vacuum clad material of the present invention forms the outer peripheral surface of the core material billet into a conical tapered surface, and the inner peripheral surface of the hollow skin material billet. After forming the conical tapered surface corresponding to the tapered surface and cleaning both tapered surfaces by immersion cleaning treatment, both billets are fitted to each other by press-fitting specifications, and both joint surfaces are the entire circumference. Since the composite billet welded over is used, air will not be entrapped between the tapered surfaces of the composite billet during extrusion or both billets will not shift, so defects such as blisters will occur in the clad material produced. Can be prevented.

Therefore, the vacuum clad material produced by the method is
Since air or oil does not leak from the layers due to defects such as blisters, it can be suitably applied as a material for a vacuum device, particularly an ultra-high vacuum device.

Moreover, the air on the mating surfaces of both billets can be automatically removed by simply press-fitting the core material billet and the leather material billet, so use a vacuum pump, etc. to remove the air on the mating surfaces. The air can be removed very easily without the need for

Moreover, the core material billet has an increased cross-sectional area from the die side end portion to the stem side end portion. Is uniformly supplied throughout the extrusion process, and the resulting clad material has an inner layer or core evenly from one end to the other end, increasing the effective length of the clad material, resulting in Therefore, it is possible to reduce the manufacturing cost of the clad material. Further, according to the method of the present invention, the amount of metal from the core material billet is uniformly supplied throughout the extrusion process as described above, and therefore the cross-sectional area of the inner layer is very small. There is an advantage that the clad material can be manufactured well.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a composite billet used in the manufacturing method of the present invention, FIG. 2 (a) is a left side view of the composite billet, and FIG. 2 (b) is the composite billet. Fig. 3 is a right side view of Fig. 3, Fig. 3 is a partial vertical sectional view schematically showing a process of press-fitting a core material billet into the hollow of a skin material billet, and Fig. 4 is a composite billet used in a conventional manufacturing method. FIG. (1) …… Composite billet, (2) …… Leather material billet,
(3) ... core material billet, (4) (5) ... tapered surface, (7) ... die side end, (8) ... stem side end.

Claims (1)

[Claims] 1. A core material billet in which an outer peripheral surface is formed into a conical tapered surface having an increased cross-sectional area from a die side end to a stem side end, and an inner peripheral surface corresponds to the tapered surface. A billet for skin material having a hollow portion formed on a conical taper surface is cleaned by dipping and cleaning both taper surfaces, and then press-fitted to each other and joined to the die side of the billet. A method for producing a vacuum clad material, characterized in that a composite billet is created by welding the end portion and the joining end portion on the stem side over their entire circumferences, and the composite billet is extruded from the die side end portion. .