Wrought alloy

Wrought alloys are alloys that are suitable for processing by forming , e.g. B. for forging , rolling or bending . The counterpart are the casting alloys , which are particularly suitable for casting . For most alloys, these are also explicitly referred to as wrought or cast alloys, for example wrought aluminum or wrought copper alloys. The iron materials are an exception : the wrought alloys are called steel , cast alloys are called cast iron .

Semi-finished products made from wrought non-ferrous alloys

Wrought alloys are an "intermediate product", also known as a semi-finished product , the manufacture of which has some special features compared to cast alloys of the same type.

In their basic analytical composition, they differ only slightly from the cast alloys. Since the main requirement of a wrought alloy is its suitability for cold or hot deformation, whereby the machinability is also important, this can require both the limitation of the proportion of some accompanying elements that are not disruptive in cast alloys and the addition of elements that are suitable and others To promote processing of the wrought alloy.

Melted in large-volume furnaces, wrought alloys are cast in simple geometric shapes as blanks (also called rolling bars ), round blanks or extrusion billets, and only after a cold or hot aging process in specially designed furnaces in a rolling or pressing plant after a cold or hot aging process that influences the structure through recrystallization subjected to further production processes for the intended purposes.

Steels and wrought alloys based on aluminum, magnesium or copper represent the majority of semi-finished products, but nickel alloys, silver and gold are also first processed into semi-finished products, from which coins are then minted or jewelry is made. Semi-finished products made from standardized wrought copper-tin alloys are processed into spring strips, which are important functional elements in various branches of industry.

Examples of rolled products

Rolled products are used, among other things, as simple or shaped sheets in vehicle construction, be it land, water or air vehicles. In building construction they are found in the form of design elements, as cladding and coverings. There are many possible uses for the rolled product foils. In this respect, the most common starting form for aluminum is the rolling ingot cast in the vertical process in the cast house.

Examples of pressed products

Pressed products, also called round blanks or billets, are manufactured in the same way as the rolling ingots using the continuous casting process, but drawn through a smooth or profiled mold. With hollow profiles, a graphite mandrel inserted into the mold is cast. A division of the smooth, profiled or hollow round blanks into disks of arbitrarily selectable thickness is common. Such discs can be extruded into round containers of all kinds, preferably into cans and their lids. Such discs can be used to mint coins and, if the strand is appropriately profiled, round technical parts of all kinds can be produced (e.g. gear wheels).

Aluminum based alloys

see aluminum alloy # wrought aluminum alloys

Copper-based alloys

Brass make up the largest share of the wrought copper alloys produced, but other copper alloys are also produced as semi-finished products, such as the above-mentioned copper-nickel alloys, which have a light color not reminiscent of copper with their> 15% nickel content of coin production stands for superiority compared to copper coins. More important are the physical properties that ensure a wide range of applications for CuNi wrought alloys.

In the case of semi-finished brass products with a predominantly 58% copper content, a distinction is made between lead-containing and lead-free alloys. With a lead content of 2.5 to 3.5%, the alloy is also called free-cutting brass (CuZn39Pb3). Due to its variable lead content, it is both cold and hot formable, suitable for drop forging and the manufacture of wires, and it can also be used almost universally.

literature

• Stephan Hasse (Ed.): Giesserei Lexikon. 17th edition. Schiele and Schön, Berlin 1997, ISBN 3-7949-0606-3 .
• Series of publications by the DKI (German Copper Institute) ( online catalog ).
• Ernst Brunhuber (translator): Cast from copper and copper alloys. Schiele & Schön, Berlin 1986, ISBN 3-7949-0444-3 , p. 99 f.

Web links

• German Copper Institute (DKI): Wrought copper-tin alloys (tin bronzes) . July 2004 (PDF file; 998 kB).

Individual evidence

1. ↑ In the ironworks , semi-finished products are also produced, traditionally as slabs, more modern usually as strand or round blank.
2. ↑ Examples of wrought copper-zinc alloys and their possible uses in: Copper-zinc alloys (brass and special brass). Informationsdruck i.5, Deutsches Kupferinstitut ( PDF  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. ).  
3. ↑ Copper coins are rarely made of expensive copper, mostly copper-plated iron.
4. ↑ Copper-nickel alloys CuNi , in: Series of publications by the German Copper Institute , accessed on June 18, 2018.
5. ↑ Copper-zinc alloys (brass and special brass). Informationsdruck i.5, Deutsches Kupferinstitut ( PDF  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. ).