Material

Aluminium

Material

Aluminium alloy AlMg3

AlMg3 alloy is characterised by medium strength, good formability and weldability in addition to good corrosion resistance, especially against sea water. It can be used wherever there are no high demands with regard to mechanical load capacity. Their main areas of application include container and apparatus construction, mechanical engineering, the chemical and food industries as well as the manufacture of packaging machinery. You can find out what exactly the abbreviation AlMg3 means, why pure aluminium is alloyed with magnesium in the first place and who came up with this idea here.

Aluminium-magnesium alloys - what are they for and who invented them?

In 1825 the Danish physicist Hans Christian Oersted was the first to succeed in isolating still impure aluminium by reducing aluminium chloride with potassium. The German chemist Friedrich Wöhler improved Oersted's method and extracted pure aluminium for the first time. From Wöhler's processes, the French chemist Henri Étienne Sainte-Claire Deville developed a technical extraction method based on the reduction of a mixture of sodium and aluminium chloride using sodium. However, this method was far too costly for mass production.

It was only in 1886 that the American inventor, engineer and entrepreneur Charles
M. Hall and the French chemist Paul Louis Toussaint Héroult independently invented a cost-effective way of producing pure aluminium by fused-salt electrolysis. The process, known as the Hall-Héroult process, is still in use today with various improvements.
Pure aluminium was therefore available in large quantities at the beginning of the 20th century. However, it had already become apparent that it could not be cleanly machined with cutting tools and that its most valuable property, its low specific weight, could therefore not be used to the desired extent. Initial attempts to alloy the element with magnesium were made shortly after its discovery. However, they failed due to incorrect mixing ratios on the one hand, and on the other hand because both alloy components were not available in sufficient purity - probably also containing larger traces of carbon, sodium or nitrogen, depending on the production method.
The first viable solution to the problem was found by Ludwig Mach, the eldest son of the Austrian physicist Ernst Mach, who in 1894 developed an aluminium alloy with two to thirty percent magnesium, which he named Magnalium. During his experiments Mach found that alloys with 10% magnesium have the same mechanical properties as rolled zinc, while alloys with 15% magnesium are equivalent to a good brass casting. At 20% magnesium, the alloy has the specific characteristics of soft gunmetal or hard-drawn brass wire and at 25% that of ordinary gunmetal.

What does the abbreviation AlMg3 stand for?

Al stands for aluminium, Mg for magnesium and the 3 for the percentage of magnesium content. In other words it is an aluminium-magnesium alloy with a magnesium content of around 3% (2.6 to 3.6%). Traces of silicon, iron, copper, manganese, chromium, tin and titanium are also contained. The material number of this alloy is 3.3535 according to the European Standard EN AW-5754 designation.
Pure AlMg-alloys like these are considered to be medium-strength, naturally hard alloys. They are easy to roll, forge and, with Mg contents of 3 % or more, also easy to weld. The welding filler depends on the magnesium content.

What can the AlMg3 alloy be used for?

While pure and ultra-pure aluminium are best suited for non-cutting manufacturing processes, their comparatively low strength values make them less suitable for cutting processes and heavy mechanical stresses. This deficit can be easily compensated by adding magnesium.
The high increase in strength is based on the high binding energy of vacancies to the magnesium atoms. The more empty spaces are occupied in this way, the lower the plastic deformability of the material.
Technically relevant aluminium-magnesium alloys contain between 3 and 10 % magnesium. In order to take full advantage of the favourable strength properties of alloys with a Mg content of more than 7 % which are demanding in terms of casting technology, these alloys require additional homogenisation annealing.
Pure AlMg alloys are suitable for a wide range of applications depending on the magnesium content. AlMg1 is used for example for roof coverings, façades, in window and door construction in addition to fittings, AlMg5 for optical appliances and
packaging. Pure AlMg alloys with 3% magnesium are used in the following areas, for example:

  • Mechanical and apparatus engineering
  • Aircraft construction
  • Mould making
  • Automotive construction (car body parts)
  • Pressure vessel construction
  • Containers for the beverage and food industry
  • Sheet aluminium and tubes for general use
  • Sheet metal fittings
  • Bolts

Da poliertes Aluminium-Magnesium-Halbzeug in Innenräumen schön blank bleibt, werden AlMg-Legierungen häufig für Beschläge oder Haushaltsgeräte verwendet.

naturblanke und eloxierte Bleche aus AlMg3

Unser Angebot an AlMg3-Produkten umfasst naturblanke und eloxierte Bleche in unterschiedlichen Stärken, die wir Ihnen gern auf die von Ihnen gewünschten Maße zuschneiden. Zusätzlich haben Sie die Möglichkeit, Ihre Bleche von uns entgraten und/oder in bestimmten Farben pulverbeschichten zu lassen.

Applications Applications

Engraving

  • Mechanical insertion by milling / engraving of texts and symbols into the material.
  • Engraving depth: 0.15 - 0.5 mm, depending on customer requirements, standard is 0.2-0.25 mm
  • As a rule, the engravings are designed and coloured with a nitro lacquer.

Anodised underprint

  • With anodised underprinting, the anodised layer of 18 - 24 ym is chemically broken up again in the upper area of 8-10 ym. This is called an uncompressed surface, and a special anodising ink is applied to the open pores by means of screen printing or digital printing. After a drying period, these are closed again chemically and with the application of temperature, the so-called sealing / compression process. With the anodised underprinting or digital anodised underprinting process, the ink is embedded and protected in the upper anodised layer of 8-10 ym, which makes the anodised underprinting scratch and solvent-resistant. It is the main printing processes in mechanical engineering, system / apparatus construction in addition to type plates.
  • Inks used in anodised underprinting must be checked for UV durability depending on the application. Indoors this is negligible, but there are differences in the exterior depending on the colour shade, e.g. black is largely UV resistant due to a soot content.
  • In anodised underprinting the choice of colours is limited since this is a special application, the colour spectrum is limited to a few standard shades.
  • In the field of digital anodised underprinting, almost all colour shades can be mixed automatically by entering CMYK values. It should be noted that colour deviations may occur due to mixing ratios and an inherent colour of aluminium. There are also colour tones that tend to have a slight violet tint when mixed, including certain shades of blue and grey.

Screen printing

  • In the classic screen printing / overprinting process, the ink is pressed through the fabric by means of its fabric screen and a rubber squeegee and applied to the underlying printing medium.
  • The printing medium is the front plate, front film or sign on to which the ink/print is applied.
  • Printing medium can be e.g. aluminium, stainless steel, brass, plastics or others.
  • It is always important to ensure that the correct printing system, i.e. ink system, is used for the print medium. An ink for T-shirts is not necessarily suitable for aluminium.
  • There are single colours or multi-component inks which are used depending on the intended purpose, in some cases the colours are baked in the oven to improve adhesion.
  • For overprint colours, almost all RAL or Pantone colours can be mixed.
  • The screen print / overprint is largely UV-resistant and is therefore often used for outdoor applications.
  • Silk screen printing / overprint is not scratch / solvent resistant, therefore the application must be checked before implementation.

Etching

  • When etching, the area where no ink is to be applied is covered with a special ink, this is known as negative printing.
  • During etching, the aluminium passes through a chemical bath, the areas which are not covered with special paint are attacked by the chemicals and a roughened surface is created, then the special paint (etching resist) is removed chemically.
  • The etched area is then usually dyed with a paint and scrapings.
  • The paint is baked in an oven. Products with aluminium

Products with Aluminium

Bitte aktualisieren Sie Ihren Browser

Leider ist Ihre Browserversion zu alt und unterstützt nicht die nötigen Technologien um diese Website richtig darzustellen.

Bitte laden Sie sich einen aktuellen Browser herunter: