JPS60227950A - Production of thin al-li alloy sheet - Google Patents

Abstract

PURPOSE:To obtain a desired thin alloy sheet having excellent workability in a process for producing a thin Al-Li alloy sheet by providing a stage for heating and melting an Al-Li alloy contg. a prescribed amt. of Li and forming the melt thereof into the thin sheet by an ultra-quick cooling method for the melt. CONSTITUTION:A base metal 3 consisting of the Al-Li alloy contg. 0.5-10wt% Li is heated and melted in the heating vessel 2 of a device 1 which executes the ultra-quick cooling method for the melt. An inert gas such as Ar or He is then forced into the vessel 2 and the molten Al-Li alloy is blown to the central opposing surface 7 of rolls 6a, 6b under rotation from a nozzle 4 to form the thin sheet. The sheet 8 is further worked by rolling rolls, by which the desired thin alloy sheet having fine crystal grains and excellent orientability is obtd. The production of the thin Al-Li alloy sheet having considerably improved workability is thus made possible without spoiling the intrinsic specific elasticity.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention provides a method for manufacturing an A6-Li alloy thin plate having excellent workability and easily and inexpensively manufacturing an alloy thin plate used for speakers, microphones, etc. Regarding.

Technical Background and Problems of the Invention Conventionally, AN-Li alloys are Ajl! -In addition to Li binary alloy, A7+-Li-Mg system, A7! Li-Cu system,
There are Aβ-Li-Cu-Mg-based alloys, etc., but the higher the amount of Li added to this superstructured multi-component alloy, the lower its density becomes, improving the Young's modulus E and increasing the specific modulus of elasticity 5f. . However, when the amount of Li added increases, the toughness decreases. The maximum amount of Lt added in a /l/2-Li alloy that has practical workability was about 2 to 3 wt%.

Conventional methods for manufacturing thin alloy sheets include the "casting and stretching method," in which a die-cast ingot is made from a molten alloy and then expanded, or the atomization method or splat quenching method in an active gas under r'1g fusion finance. "Powder metallurgy method" which uses A4 alloy powder, solidifies it using powder metallurgy method, and expands it.
There is.

An example of the physical properties of the /1-Li alloy manufactured by such a manufacturing method, such as density ρ, Young's modulus E, and specific elastic modulus, is shown in Table 1 below.

Furthermore, the relationship between toughness (yield point) and elongation (%) of these typical AR-Li alloys is shown in the graph of FIG. 1. Although these Al2-Li alloys have been improved in strength and elongation by making their crystallinity finer by adding Mn or Zr, their toughness is not sufficient. Among these, Al1-L
Although the i-Mg alloy has better overall properties than the AR-Li alloy, its elongation is lower than the existing Aβ=Li alloy. Aj again! -Li-Cu alloy and /1
It can be seen that the -Li-Mg alloy has significantly higher strength and elongation.

However, in these AR-Li alloys, as the amount of Li added increases, Aj! - Because the toughness of Li-based alloys decreases, conventional ingot methods and powder metallurgy methods, for example,
It was not possible to process thin plates with a thickness of less than μ.

In addition, the toughness of conventional AR-Li alloys decreases significantly as the amount of Li added increases, but there are limits to thin plate processing using the ingot method and powder metallurgy, so it is natural that the amount of Li added must be suppressed as much as possible. No.

Comparing the properties of this alloy with Al2, the density is significantly reduced and there is a limit to increasing the Young's modulus E, so it cannot be said that the properties of this alloy are fully utilized.

In addition, especially in the conventional powder metallurgy method, measures are taken to prevent the alloy from oxidizing during production, reduction by adsorption of hydrogen gas, and even L
It has the disadvantage that countermeasures against powder explosion caused by the strong chemical properties of i itself and equipment costs are expensive.

Purpose of the Invention This invention has been made in view of the above points, and its purpose is to use AI! It is an object of the present invention to provide a method for producing an A/-Li alloy thin plate in which the workability of the -Li alloy can be greatly improved without impairing the inherent large specific elastic modulus of the -Li alloy.

Embodiment of the Invention An embodiment of the invention will be described below with reference to FIGS. 2 to 5.

First, FIG. 2 shows an example of an apparatus 1 for carrying out the melt ultra-quenching method.

2 is a heating container in which the Al2-Li alloy base material 3 is accommodated, and 4 is a nozzle provided at the lower end of the heating container 2. The heating means for heating the heating container 2 is, for example, a coil heater 5 wound around the outer periphery of the heating container 2.

5a and 5b are quenching rolls that are rotatably provided opposite to each other below the nozzle 4, and when an inert gas such as Ar is injected into the heating container 2, the nozzle 4
The Aff-Li alloy base material 3 melted from the Aff-Li alloy base material 3 is sprayed onto the central matching surface 7 of the two rolls 6a and 6b and cooled very rapidly.

Further, the entire device 1 is covered with Ar in order to prevent oxidation and hydrogen adsorption due to highly active Li as a composition of Al1-Li alloy.

It is better to install it in an inert gas atmosphere such as He or in a vacuum.

First, as a first step, an AR-Li alloy base material 3 containing 0.5 to 10 wt% Li is placed and heated and melted.

After that, as a second step, by injecting an inert gas such as Ar into the heating container 2, the two
The mixture is sprayed onto the center abutting surfaces 7 of the two rolls 5a and '5b, and is ultra-quenched to obtain an AR-Li alloy thin plate 8. In this case, instead of using the twin roll method shown in FIG. 2, it is also possible to use a single roll method in which the molten base material 3 is sprayed onto one roll 6a of the wrapping Wl' as shown in FIG. 4 to cool it extremely rapidly.

Thereafter, in a third step, the AR-Li alloy thin plate 8 is press-fitted between opposing rolling rolls 9a and 9b and further rolled (see FIG. 3). The rolling method in this case is unidirectional single-stage rolling, but this rolling method is not suitable for the Af
Depending on the shape of the f-Li alloy thin plate 81, it may be rolled using a cross rolling method, a multi-stage rolling method, or the like.

AR-Li alloy thin plate 8 manufactured by the above manufacturing method
1 is a polycrystalline body, and its crystal grains are finer than conventional AR-Li alloys in which various additive elements are added to the AR-Li alloy using the ingot method or powder metallurgy. The direction of rapid cooling of roll 6 a H6b is Aj from the roll surface! Since it is always constant in the thickness direction of the -Li alloy thin plate 81, much smaller crystal grains can be obtained.

Further, the direction of rapid cooling of the An-Li alloy thin plate 8 manufactured in this way from the molten state is between the two rolls 6a and 5.
Since the crystal grains are arranged relatively regularly from b to the deep part (in the thickness direction) of the A#-Li alloy thin plate 8, the orientation of the crystals is improved.

This Affi-Li alloy thin plate 8 exhibits considerable ductility by cold rolling. For example, when the amount of Li added is about 10 wt%, it is possible to produce a β-Li alloy thin plate 8 of about IOμ.

Incidentally, the graph shown in Figure 5 is based on the diameter of the roll or φ140.
By using the twin roll method, the thickness of the plate immediately after super-quenching the melt was 81μ,
When an Al-Li alloy thin plate 8 with an added amount of 3 wt % of Li is rolled in one direction in one step by a twin roll method under the condition that the rolling load is 1000 kg by rolling rolls 9 a and 9 b with a roll diameter ψ 60 in the subsequent stage. The relationship between the longitudinal elongation rate (%) and the thickness μ) according to the number of cold rolling of the Ae-Li alloy is shown by curves X and Y.
It can be seen that the elongation increases with repeated rolling.

In FIG. 5, Lo is the length of the thin alloy sheet 8 before cold rolling, and L is the length of the thin alloy sheet after each number of passes.

The characteristics of the elongation rate shown in Fig. 5 are as follows: The overall composition of the elements contained in the ρ-Li alloy thin plate is 0.5 to 10 wt% Li;
If added, even small amounts of other elements such as Mn and Z'' will exhibit excellent ductility and the specific elastic modulus%
is 4.3 (X 109cm), density ρ is 2.2 [g/
cml], Young's modulus E is 950° (kg/m2), etc., and these physical properties are high.

Further, in the above embodiment, the Al-Li alloy base material 3 is placed in the heating container 2 and heated and melted to produce the β~Li alloy thin plate 8.
Aff~Li alloy thins Fj and B may be manufactured by supplying and melting Li and Li respectively in the heating container 2 and alloying them.

Effects of the Invention As described above, the present invention can improve Al2-1. Since the melt ultracooling method is applied to the i-alloy, its crystal grains can be made finer and its orientation can be improved, resulting in improved workability in cold rolling, press working, etc.

[Brief explanation of drawings]

Fig. 1 is a graph showing the relationship between toughness (yield point) and elongation rate (%) of conventional Al-Li alloys, and Fig. 2 shows an example of an apparatus for carrying out an embodiment of the present invention. The cross-sectional view shown,
FIG. 3 is a sectional view showing the rolling means in the latter twin roll method, FIG. 4 is a sectional view showing the other side of the apparatus when implementing this embodiment, and FIG. It is a graph showing the relationship between the elongation rate in the longitudinal direction and its thickness depending on the number of rolling times when a manufactured Al-Li based alloy thin plate is rolled by the twin roll method. 1.1'... device, 2... heating container, 3... Al
-Li alloy base material, 4... Nozzle, 5... Coil heater, 6a, 6b, 9a, 9b'' rolling roll, 8.
A ff-Li alloy thin plate. Figure 5 Pa55m number

Claims (1)

[Claims] Production of an AA-Li alloy thin plate characterized by including a step of heating and melting an A4-Li alloy containing t, 1t-0.5 to 10 t% of A6 and thinning it by a melt ultra-quenching method. Method.