DE10337971A1 - Method for increasing the strength and / or load capacity of workpieces - Google Patents

Abstract

A method for at least locally increasing the strength and / or loading capacity of workpieces (10) is proposed, wherein a first workpiece (11) is first produced by means of a conventional production method. The method comprises the following method steps: DOLLAR A a. The first workpiece (11) is subsequently provided with a hole (13) in the region of the strength to be increased and / or increased load capacity, DOLLAR A b. Subsequently, in the hole (13) from a strength and / or loadability increasing material existing second workpiece (12) is introduced, DOLLAR A c. Finally, in this state, the second workpiece (12) against the first workpiece (11) by the method of friction welding relative to each other until reaching the welding temperature below the melting temperature of both workpieces (11, 12) rubbed, so that a Reibschweißverbindung between the first workpiece (11) and the second workpiece (12) for forming the workpiece (10).

Description

The The invention relates to a method for at least locally increasing the Strength and / or resilience of workpieces, with a first workpiece first by means of a conventional manufacturing process is produced.

Certain Workpieces, made of certain materials by means of known, conventional Manufacturing processes are produced, for example. By casting Procedures have regard to their strength and / or resilience when used in the intended installation locations or with regard to on the intended installation purposes though in the selection of the workpiece forming material, for example. a desired one low weight, as it can be found, for example, in light metal materials is, however, these show material-specific often not the Strength and / or load capacity for the intended use of the workpiece is required or desired becomes. In these cases the low strength and / or the low load capacity of such made of such materials workpieces, at least on highly stressed Locate the workpiece to encounter these areas already in the manufacturing process Materials "reinforced" to the desired higher Strength and / or load capacity of the workpieces at least in these local Reach areas. For example, in a light metal workpiece produced by known metallurgical casting techniques during the casting process a sprue placed in appropriate place in the mold and with the casting material poured so that, in fact, as desired, at least one local increase in strength and / or the resilience is reached.

Especially this leads to metallic workpieces regularly to incompatibilities regarding the electrochemical potentials of the material of the workpiece and the material of the sprue and also the residual stresses. This results in how the practice in such composite workpieces has shown, besides reinforced Occurring corrosion phenomena also the formation of cracks as a result of said unfavorable Residual stresses of the two materials of the two workpieces.

Puts such composite workpieces the normal environment or even exposure to saline, aqueous solutions out, such workpieces fail within the shortest possible time Time. Partially very different physical play in it and mechanical properties of the workpiece forming material and of the sprue forming material. After all also result in adverse internal stresses caused by the used actual casting process arising in the course of production.

It is therefore an object of the present invention, a method of to create the aforementioned type, with the at least locally Increase the Strength and / or load capacity of workpieces is achieved, namely for workpieces, in their basic configuration by means of different, general manufactured and possibly also conventional manufacturing process have also been produced in accordance with previous manufacturing processes workpieces increased Temperature resistance is to be achieved and wherein the method is inexpensive and should be feasible with little equipment.

• a. das erste Werkstück nachfolgend im Bereich der zu erhöhenden Festigkeit und/oder erhöhenden Belastbarkeit mit einem Loch versehen wird und nachfolgend
• b. in das Loch ein aus einem festigkeits- und/oder belastbarkeitserhöhenden Werkstoff bestehendes zweites Werkstück eingebracht wird und
• c. in diesem Zustand das zweite Werkstück gegenüber dem ersten Werkstück nach der Methode des Reibschweißens relativ zueinander bis zum Erreichen der Schweißtemperatur unterhalb der Schmelztemperatur beider Werkstücke zur Schaffung einer Reibschweißverbindung zwischen beiden Werkstücken gerieben werden.

Solved the task gem. the invention in that

• a. the first workpiece is subsequently provided with a hole in the region of the strength to be increased and / or increased load capacity, and subsequently
• b. in the hole from a strength and / or loadability increasing material existing second workpiece is introduced and
• c. In this state, the second workpiece relative to the first workpiece by the method of friction welding relative to each other until reaching the welding temperature below the melting temperature of both workpieces to create a Reibschweißverbindung between the two workpieces are rubbed.

through the process of the invention is advantageously achieved that Composite workpieces make, at least locally the properties with respect on strength, load capacity and resistance at high temperature and a high wear resistance have and thus produced workpieces thus used in areas can be the previously for such workpieces completely inaccessible were. It can, if for example, the first workpiece made of a light metal material, for the entire workpiece all advantageous properties of the light metal are used, for example the low weight or its low density, beyond but also strength and strength Resilience and temperature resistance properties at least in the local area of the workpieces be reached, the previously only workpieces made of materials with very great specific Weight or larger Dense or extremely difficult to process materials and very costly to provide Materials accessible were.

In principle, the inventive Procedure be carried out using all variants of friction welding.

Gem. an advantageous embodiment of the method is the hole in first workpiece a bore and the second workpiece has a rotationally symmetric Form in which the method of friction welding in this case, the Friction stir welding is, in which case the friction cone welding can be used, which is a special form of friction stir welding. This way you can target reinforcements in certain local areas of the first workpiece can be achieved, the overall strength and / or load capacity of the workpiece increase. Thus, for example, the hole may be either cylindrical or conical, wherein the rotationally symmetric second workpiece in this case either cylindrical or correspondingly conical.

The Hole or the hole can at the appropriate point of the first workpiece the Traverse workpiece, but it is also possible to form the hole or hole as a blind hole or blind hole, so that one Soil remains in the first workpiece.

Gem. a further advantageous embodiment of the method is the Hole or bore in the first workpiece by the second workpiece in the one another connected state at least partially filled, i. it is possible, yes in the second workpiece to form a through hole or a blind hole or a blind hole, according to the shape of the second workpiece, before this through the friction welding with the first workpiece is connected.

Basically the first workpiece using any suitable manufacturing process getting produced. Preferably, however, the first workpiece in a cast manufacturing process made, which has the advantage that the first workpiece very economical in the form of a mass casting technique known from the prior art Process can be produced, whereas the second workpiece that the special desired strength and load capacity properties has, which then sought in the composite of both workpieces for the entire work are used and, for example, as commercially available semifinished products can be so that too by the achievable according to the invention Composite component only minimal cost increases over a normal means casting technical measures produced workpiece to be recorded.

Gem. a further advantageous other embodiment of the invention At least the first workpiece made of a light metal or a light metal alloy, preferably the light metal Magnesium or a magnesium alloy is or ultimately beneficial the light metal is aluminum or an aluminum alloy.

aluminum and magnesium incl. its respective alloys, come in the lightweight construction industry, i. in the automotive industry and in the air and Space industry an ever stronger becoming an important role. Especially in the field of motor vehicle construction results in addition to the low density of aluminum and magnesium also the requirement of workpieces or provide components made of these materials extremely inexpensive to be able to so that workpieces in this Area already now in particular by means of known casting technology Process are produced. Nevertheless, this results for this Cases the Demand that this at least locally high mechanical and electrochemical stresses have to withstand. Combined according to the invention good pourability of magnesium or magnesium alloys or aluminum and aluminum alloys as well as their good mechanical workability with the properties the material of the second workpiece, which has a high mechanical and electrochemical loading, but less so Well workable and much less castable, in this example to stay, as that of the first workpiece.

The invention will now be described in detail with reference to the single drawing with reference to an embodiment. This shows:
In four steps the execution of the process for obtaining a composite piece of two workpieces, which are joined together by the method of friction welding.

The workpiece 10 is initially the first workpiece 11 before, which is shown in the individual manufacturing steps according to pos. 1st to 4th in section. The first workpiece 11 may be any suitable workpiece, in the present case a flange-like projection 17 has, cf. Pos. 1. The first workpiece 11 is, for example, produced by means of known casting processes and can, for example, consist of an aluminum or magnesium alloy or any other suitable material.

In the flange-like projection 17 becomes a hole 13 drilled, or introduced in any other suitable manner. The hole 13 is conical in the present case and has no hole bottom. It should be noted that the hole or the bore 13 also in the first workpiece 11 may be formed, that a soil in the hole or the bore 13 remains (not shown).

Subsequently, a second workpiece 12 , which in the example shown here is rotationally symmetrical and also conical, by means of a device not shown here in rotation, cf. arrow 15 , offset and in the direction of movement, cf. arrow 16 , in the hole 13 while continuously maintaining the rotational movement in the direction of movement 16 introduced.

As a result of the contact between the first workpiece 11 and second workpiece 12 a friction welding process takes place, which is maintained until the welding temperature below the melting temperature of both workpieces is reached.

In this case, a state gem. Pos. 3 of the drawing reaches where the hole 13 with the second workpiece 12 forming a Reibschweißverbindung between the first workpiece 11 and the second workpiece 12 is filled.

Gem. Pos. 4, the second workpiece 12 , as shown in Pos. 2, also with a through hole 14 be provided so that the second workpiece 12 also in the final position or in the last procedural step acc. Pos. 4. a through hole 14 having. In this case, the separate formation of a through hole 14 Not required by a drilling or milling process.

But it is also possible, the through hole 14 through the second workpiece 12 durchzubehhren or to-milling, after it gem. Pos. 3. has been formed, ie after a Reibschweißverbindung between the first workpiece 11 and the second workpiece 12 is reached.

10

workpiece

11

first workpiece

12

second workpiece

13

Hole / bore

14

Through Hole

15

arrow (Rotation)

16

arrow (Direction of movement)

17

head Start

Claims (7)

Method for at least locally increasing the strength and / or loading capacity of workpieces, wherein a first workpiece is first produced by means of a conventional manufacturing method, characterized in that a. the first workpiece is subsequently provided with a hole in the region of the strength to be increased and / or increasing load capacity and subsequently b. a second workpiece consisting of a material that increases strength and / or load capacity is introduced into the hole, and c. In this state, the second workpiece relative to the first workpiece by the method of friction welding relative to each other until reaching the welding temperature below the melting temperature of both workpieces to create a Reibschweißverbindung between the two workpieces are rubbed. Method according to claim 1, characterized in that that this Hole in the first workpiece a bore is and the second workpiece is a rotationally symmetric Form, wherein the method of friction welding that of the friction stir welding or the Reibkegelschweißens is. Method according to one or both of claims 1 or 2, characterized in that the Hole or bore in the first workpiece by the second workpiece in the one another connected state is at least partially filled. Method according to one or more of claims 1 to 3, characterized in that the first workpiece produced in a casting production process becomes. Method according to one or more of claims 1 to 4, characterized in that at least the first workpiece made of a light metal or a light metal alloy. Method according to one or more of claims 1 to 5, characterized in that the light metal Magnesium or a magnesium alloy. Method according to one or more of claims 1 to 5, characterized in that the light metal Aluminum or an aluminum alloy.