Ductility

Ductility ( from the Latin ducere ( pull, carry, lead ) is derived ) is the property of a material to deform plastically under load before it fails. For example, breaks glass with no apparent deformation; Steel, however, may be more than 25% plastically deform (depending on steel grade, see also structural steel ) before it breaks. Gold is so ductile that it can be cast to a thickness of a few atomic layers, see gold leaf.

Materials with this property are in building important so that a structure with a lot of stress his failure clearly visible " announce " before it breaks down. In the automotive industry, ductile materials are required, since a car in the event of an accident deform plastically and is not to rip apart. Formerly a synonym for malleability ductility. Ductile materials are readily cold formable, eg by deep drawing, bending or stretching. Nichtduktile (ie brittle) materials could cause by flying parts from the bursting injuries.

Survey

In principle there are two possible processes for plastic deformation of crystals, so in particular for metals, crystalline structure, after the load has exceeded the yield point. Either they deform flexible, then they are called ductile or brittle they deform and burst, then they are called brittle.

• In geology, the term for rocks is particularly the lower continental crust used under tectonic stress not brittle, but plastically deform.
• In the testing of bitumen, a sample is clamped in a so-called Ductilometer and pulled apart until the resulting bitumen thread breaks. The length of the thread at the time of breakage is designated as the ductility of the bitumen. The polymer-modified bitumen which according to DIN EN Kraftduktilität interested 13589th this bitumen thread of 30 mm is stretched at 400 mm and calculated the work that was done on the stretch of 200 to 400 mm.

Many materials lose their ductility at low temperatures and become brittle. Because of this behavior, many structures ( bridges, ships, etc.) have been destroyed.

Definition

The ductility is best defined in terms of a schematic representation. There is shown a crack in a material. Top and bottom of the crystal WOULD a force in the normal direction. Then deforms the crystal by easily the two monolayers separated from each other, without being changed themselves in their structure, breaks apart obviously the material and it is referred to in this sense as brittle. Deforms the crystal, however, by the monolayers sequentially slide upwards, so flows in this sense the material and it is referred to as ductile.

Hazard statement with electrical contacts

If electrical contact points soldered with solder, and comes mechanical pressure - for example by a screw - into play, so the tin can dodge in solder with time, so that the connection is loose. This danger is especially for wires that are more flexible than single-core ( and correspondingly thicker ) cable through their Mehradrigkeit. Performs the affected loose end power, it may show a short circuit.