Spray forming

Spray forming is a manufacturing process from the group of primary forming method. Here, a liquid molten metal is sprayed through a nozzle for the production of net-shape components or semi-finished products (blocks, bolts, washers, plates, pipes ). The spray is directed to a substrate or a collecting surface where the liquid or in the process solidifying melt droplets are " compacted " into a solid body. After treating the collection surface in a slow rotation and pulls them down gradually away, then "grows" in return for a bolt-shaped body up.

Origin

As one of the pioneers of spray compaction to Professor Singer, the new ways of original shaping of steel studied in the 1970s at the University of Swansea in Wales. Starting from the spraying of metallic melts, which was already known from powder metallurgy, but was allowed to melt sprayed droplets do not freeze to metal powder, but the spray was " compacted " directly to the desired solid. The detour of powder metallurgy, namely, pressing the powder into a mold, and sintering is prevented.

Benefits

The advantages of the spray forming arise from the high cooling rate. This is with 1,000 to 10,000 K / s, only slightly below the cooling rates of powder metallurgy, but several orders of magnitude above the cooling rates of classical casting method. Thus the possibilities of metallurgy are considerably extended compared to the casting process. Through the Spray Forming Alloys can be produced which could produce neither the technology nor the foundry metal forming. Spray-formed steels have a particularly homogeneous material structure, segregation can be largely avoided. Special structural components, which are needed to achieve a particular material properties, such as Manganese sulfides or carbides can be produced much more fine-grained during spray than with the casting technique. As a result, strength and toughness are improved. Can be prepared by spray-forming particularly powerful alloys with high strength and temperature strengths also in aluminum and magnesium alloys.

Disadvantages

A disadvantage of the spray forming is in the spray losses ( overspray ). As in painting, it is inevitable that a certain proportion of the spray misses his target. Another potential drawback is that there is a 100 % non-porous material with the spray forming usually do not restore.

Variants

• Atomizing the melt can be effected by a gas jet, or by centrifugal force.
• A gas nozzle can be operated with an inert gas or a reaction gas.
• In addition to Schmelzsprühstrahl you can perform with a powder blasting solid particles.
• You can use multiple Schmelzsprühstrahlen simultaneously.
• The substrate can be moved linearly and rotationally in many ways.

• Urformen