Forged aluminum wheels

Hot forging and cold reeling

Forged aluminum wheels are one piece, которая изготавливается из одной заготовки металла путем горячей ковки с последующей горячей или холодной ротационной деформационной обработкой (раскаткой) и обязательной механической обработкой.

forging technology makes it possible to realize the most diverse design, almost as well as in the alloy wheels. Forging the entire rim of the one piece ensures a higher strength properties and smaller weight as compared with composite constructions, as well as cast aluminum wheels and, of course, with steel wheels.

kovanye-alyuminievye-kolesnye-diskiFigure 1 - Forged aluminum wheel Alcoa wheels manufactured for "tuning" vehicles

Benefits forgedx aluminum wheels

  • Forged wheels are usually at about 25 % lighter alloy wheels.
  • While molding and is a cheaper process, alloy wheels show significantly lower mechanical properties, than forged wheels.
  • Components forged alloy composed of two or more parts, which are interconnected in different ways. In some composite disks used bolting, in others - welding or adhesives. In any case, the compounds in composite rims act as stress concentrators and place of occurrence of fatigue cracks. Bolting can be a source of vibration to subside or.
  • Forged aluminum wheels are superior cast aluminum wheels, especially with respect to impact and fatigue strength. Forged wheels do not break under impact tests, whereas it impact tests are a problem for alloy wheels.
  • Increased fatigue strength of forged wheels gives designers the opportunity to further reduce their weight, in the same time, staying on the fatigue strength of no worse than cast wheels.

kovanye-alyuminievye-kolesnye-diski-devyat2-22-3Figure 2 – Кованые колесные диски: разнообразие вариантов дизайна

Advantages of aluminum forging

1) Процесс ковки дает возможность полного использования свойств материала в отношении:

  • механических свойств;
  • вязкости;
  • fatigue strength.

2) Технология ковки позволяет достигать очень жестких допусков по размерам колесных дисков. The forged rims are no porosity and shells, which means high reliability.

3) Поверхность кованых колес дает более широкие возможности для ее конечной отделки.

Aluminum alloys for forging disks

standard alloys, которые применяются для кованых алюминиевых колесных дисков являются термически упрочняемые сплавы системы легирования AlMgSi (серия 6ххх):

  • 6082 in Europe and
  • 6061 in North America.

Full designation aluminum alloy 6082 according to the European Standard EN 573-1 выглядит следующим образом: EN AW-6082 или EN AW-AlSi1MgMn, and alloy 6061 - EN AW-6061 или EN AW-AlSiMgCu. Alloy 6082 - is an analogue of the domestic aluminum alloy AD35, a raft 6061 - alloy AD33 GOST 4784-97.

Wrought aluminum microstructure

Ковка вытягивает микроструктуру металла вдоль направления течения металла (рисунок 3) и тем самым позволяет полностью использовать потенциал сплава по прочности и вязкости.

makrostruktura-alyuminievogo-kolesnogo-diskaFigure 3 – Вытянутая зеренная структура алюминия в кованом колесном диске (источник – фирма Alcoa)

Although forged, and alloy wheels must meet the same specifications of the strength characteristics and reliability indicators, forged wheels are more resistant to overloading and incorrect use.

Compared with alloy wheels, forged wheels exhibit a high fatigue endurance due to the absence of porosity and the presence of small, гомогенной микроструктуры (рисунок 4). Moreover, dense microstructure deformed literally will reach mirror surface disk after machining of a diamond tool.

4Figure 4 – Кривые усталости для кованого сплава AlSi1MgMn-T6 (6082-T6) и литого алюминиевого сплава AlSi7Mg0,3-T6 (источник – фирма Otto Fuchs)

Manufacture of forged aluminum wheel

Conventional technology for manufacturing of forged aluminum wheel includes a plurality of forging operations, rough machining, heat treatment, finish machining and various intermediate and finishing treatment depending on the construction and design.

Technology company Otto Fuchs chain for the manufacture of lightweight forged wheels, first used back in 1995 году, comprising the steps of, shown in Figure 5.

kovanye-aljuminievye-diskiFigure 5 – Технологическая цепочка изготовления облегченных кованных колесных дисков на фирме Otto Fuchs (источник – фирма Otto Fuchs)

A source: European Aluminium Association, 2011

Cast aluminum wheels

Welding aluminum wheels