DE3218284A1 - Process for conductive welding of amorphous metallic materials - Google Patents

Abstract

The present patent application describes a welding process for welding two metal bodies, one or both of which are in an amorphous statewelding is performed conductively with extremely short, steep-edged current pulses, so as to ensure prevention of harmful crystallisation in the heat-affected zone.

Description

όΔ Ι ÖZÖ

Dr. -Tng. Bogdan Kocjancic Sulzaer SIr. 12th

1000 Berlin 33

-2-

Berlin, February 11th, 1982

Patent application

Description of the invention and

Claims

(a total of 0 pages with 5 images)

Title:

(technical name)

Field of use:

Purpose:

State of the art:

with references and

State of the art criticism:

Process for the conductive welding of amorphous metallic materials.

Welding amorphous metallic materials and welding amorphous with crystalline metallic materials.

Provision of an i'Tige process that is more suitable than competing methods /

For similar applications for which the method according to this invention can be used there are other joining techniques:

1. Conductive welding with a capacitor discharge f 1]

2. Explosion welding [2]

3. Ultrasonic welding

The following nacives adhere to these procedures:

available 1.

The energy input in method 1 is compared to the one presented Process not, can be optimally dosed. The course of sweat! Current corresponds to the limit of a capacitor discharge. In contrast sr. is electronically regulated in the presented procedure! Current pulse with square wave, its duration because it is below the minimum pulse duration when the error occurs " ren 1 can be held.

The hot results are the application Dos procedure 2 is generally problematic in the continuation.

Task:

Solution:

-3-

Regarding V vr'L 3.: The method 3 is only for the welding of particularly krisfallisa-I ion carriers amorphous works ι of fo
suitable (see [3]). . Furthermore, when purchasing the system, the investment costs are high.

In general, the dosage of the energy supplied is much more critical in processes 1 and 2 than in the method according to the invention.

Development of a process for low-cost welding of amorphous metallic materials Materials, whereby the development of an application-technically harmful crystallization of the amorphous material is avoided in the heat affected zone.

According to the invention, the object is achieved in such a way that a direct current (alternating current) is sufficient high current density with a defined pulse duration with the help of an attached electrode with a high Thermal conductivity through the contact surface of the amorphous or amorphous to be welded and crystalline metals. The strength of the current is set so that the largest possible weld nugget is created and at the same time a crystallization of the amorphous material is prevented. The current pulse has approximately a rectangular current-time curve (Fig. 1).

The total welding energy introduced is determined by a corresponding combination of amperage and pulse duration. Due to the process, the pulse duration can be reduced to a minimum value can be set by just 0.02 ms. The electrode must be used during the welding process have perfect contact with the weld metal. The fleas of the electrode force is here of subordinate importance, since the current strength hardly depends on the contact resistance is. The use of static or rolling electrodes is part of the method according to the invention locked in.

The relationship between the course of performance , the F: iekt rodengesiali, the ElektrodonwerklolT, the Klekl rodenkrafl., the ZiKsamnienser / .ung dft · / u -vo! '. welding materials and the resulting strength of the welded joint can be summed up in each individual case in the same way as in joining technology in general is common. '.-- "_

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Achievable benefits:

Description of a
Embodiment:

The desired prevention of crystallization in the heat-affected zone takes place through rapid heat dissipation into the electrodes and the weld metal that is not heated at the same time. The cooling speeds achieved are the same (Irößeiior-diiiiii /. ¹ , as diojonigpn hoi ιϊ ^ ν I Icr.slel Ιιιιιι ^1. <Ιι · η; i 11 κ>ij> [ι · -ι ι! Vl: ι Ι «· | · ι; ι I ::.

• Due to the possibility of introducing the highest amounts of energy into the weld metal in extremely short periods (square-wave power pulse), the high cooling speeds are achieved, those to prevent crystallization ^ processes and the associated damage of the amorphous material are necessary. The unproblematic application of the electrode force enables the Vei to be well adapted to a complicated workpiece geometry.

Example 1: Body made entirely of glass-like Metal materials of the same composition Ni 78 Si 8 B 14 (the indices indicate the atomic percentages an) were welded under different conditions ", one being electronically controlled Welding device was used. The pulse shape was such that the energy was within 0.07 ins to 1 ms could be delivered to the welding point (Fig. 2).

The welded amorphous strips with the dimensions 3.0 0.03 * mm were fixed between spherical copper electrodes with an electrode force of approximately ^ς 0 [Ν]. The achieved tensile shear strength of the welded joint as a function of the selected pulse duration is shown in Figure 3. The correct lens geometry and areas of crystallization in the event of faulty welding are shown in Figures 4 and 5.

Literature:

[1] Offenlegungsschrift 27 5ί 025

[2] 'Ilammerschmid: M., Kreye fT. : Joining process for metallic glasses.

DVS (ifi, p. 23-28

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Claims (2)

'ό Z "I Ö Z Ö 4 Patent Claims: Claim';!; ■ a) Welding of two 'metal bodies to one another, both or one of which are in the amorphous state. The overlapping parts are clamped between electrodes and subjected to an electric current in this way that a welded connection of amorphous or partially amorphous s'riiklur is created! The current pulse has a rectangular shape over time, which is characteristic of the registered procedure. c) The method is characterized in that the strength of the welded joint is shown to be independent of the electrode force used in a wide range (electrode force range: 10-100 (N)). dj The electrodes, which conduct heat well, meet two requirements when using the method Functions: 1. Introduction of the electric current. 2. Sufficient ^ rapid Cooling of the weld metal. Subclaims: 1. The generation of extremely short-term and steep flanked temperature pulses (sub-millisecond range) , there a) because of the low impedance of the Las'kreises correspondingly rapid increases in current possible ° ind ^f with a corresponding design of the Las circuit and the control and switching equipment), b) because of the effective cooling (inwards and outwards, possibly also supported by surrounding, intensely heat-dissipating media) a very rapid heat extraction is possible. 2. Electrode stationary or sliding or rolling. COPY