thermally neuprochnyaemye aluminum alloys They include the various grades of aluminum and other alloys, in which an increase in strength properties is achieved due to:
- alloying and solid solution
- strain hardening (hardening, nagartovki) from the annealed state.
The main alloying elements of these alloys include:
- manganese and
Additional alloying elements:
- iron and
Properties thermally alloys neuprochnyaemyh
Aluminum alloys, which are not susceptible to heat treatment have the following general properties:
- relatively low strength,
- high plasticity and
- high corrosion resistance.
This group includes alloys:
- aluminum grades (series 1xxx);
- systems aluminum-manganese (alloys AMts – series 3xxx);
- systems aluminum-magnesium (alloys AMg – series 5xxx);
- some alloys of the 7xxx series and 8xxx.
The main mechanism of hardening of these alloys, if necessary, no heat treatment, a cold working (work hardening) by plastic deformation.
Technical aluminum (series 1xxx)
Stamps technical aluminum may contain up 1 % various additional additives or admixtures.
technical aluminum structure is composed of a small volume fraction of iron and / or silicon, which form insoluble particles in an aluminum matrix.
aluminum cold deformation 1100
technical aluminum Hardening occurs substantially only due to strain hardening – hardening (slander). The maximum level of alloy strength reaches 1100 (AD), which is often considered “standard” technical aluminum. Fully cold-worked aluminum alloy 1100 reaches tensile strength 165 MPa yield strength 150 MPa and a total elongation 5 %. Technical deformed aluminum is used in nearly all areas of industry. Most technical aluminum is on the packaging, in Chemical Engineering, energy and construction.
Al-Mn and Al-Mn-Mg alloys (3xxx series)
3xxx series aluminum alloy contains from 0,3 to 1,5 % manganese.
The only binary alloys, aluminum-manganese, which is of industrial interest, It is an alloy 3003 (AMc). This alloy has about 1,2 % manganese, aluminum which increases strength by solid solution hardening and its precipitation hardening particles Al6Mn.
The role of magnesium in the alloys 3xxx
Addition of magnesium to the alloy of aluminum-manganese greatly increases its strength properties due to solid solution strengthening. for instance, alloy 3004 (D12) has a strength of about 180 MPa in the annealed condition compared with 110 MPa alloy 3003.
The content of manganese in 3xxx alloys is much lower than its theoretical maximum solubility in aluminum;. The thing is, unavoidable impurity that reduces manganese iron solubility in aluminum;, and the formation of coarse particles Al6Mn may adversely affect the ductility.
Manganese, Unlike other elements, It does not impair the corrosion resistance of aluminum, and even improves it. Therefore 3xxx alloys compared to pure aluminum higher strength and corrosion resistance.
Aluminum alloys 3003 and 3004
Both alloys 3003 and 3004 have high corrosion resistance and high strength in combination with high ductility. These alloys are used there, requiring moderate strength and good weldability. They are increasingly being used successfully in those areas, where previously used various brands of aluminum, providing a high strength without loss of corrosion resistance.
In particular, alloy 3004 in large quantities used in the manufacture aluminum cans Beer and soft drinks.
Aluminum alloys 3005 and 3105
alloys 3005 (MM) and 3105 have a good combination of strength, formability and corrosion resistance and is therefore widely used in construction and finishing materials.
Al-Mg alloys (5xxx series)
5xxx series aluminum alloys contain 0,8 to 5 % magnesium as the principal alloying element. Although magnesium with decreasing temperature and decreases its solubility in aluminum;, Al-Mg alloys do not exhibit substantial age hardening at a magnesium concentration less than 7 %.
Alloys containing magnesium 1 to 6 %
However, the magnesium provides a significant strengthening of the solid solution of aluminum and increases susceptibility to work hardening. for instance, annealed alloy with Al-1Mg 1 % Magnesium has a yield strength 40 Strength MPa 125 MPa. By increasing the magnesium content to 6 % yield strength increases to 160 MPa, and strength – to 310 MPa. Elongation in the range of magnesium content is high and exceeds 25 %.
Al-Mg alloys combine a wide range of strength properties, good formability, good weldability and high corrosion resistance.
The most valuable quality 5xxx alloys is their behavior when welding high-strength alloys industrial welding processes. Weld strength is annealed state for most alloys exhibit high ductility and. The high strength of these alloys and the high quality of welds that provide them widely used in transport engineering and construction.
Cryogenic 5xxx alloys
Good mechanical properties of the alloys at low temperatures 5xx used to allow different cryogenic techniques.
Other alloys netermouprochnyaemye
Aluminium alloy 8001
Alloy 8001 It contains 1,1 % nickel and 0,6 % iron, and has good corrosion resistance in hot water and at high pressure. Its mechanical properties similar to the properties of the alloy 3003. It is used in the nuclear industry.
Aluminium alloy 8011
Alloy 8011 (Al-0.75Fe-0.7Si) is used for the manufacture of bottle caps. It has the properties, which are suitable for large plastic deformations, that occur during deep planting.
Aluminum alloys 8081, 8280 and 8009
alloys 8081 (Al-0,75Fe-0,7Si) и 8280 (Al-6,2Sn-1Cu-1,5Si) have excellent antifriction properties and are used in bearings for automobiles.