COMPACTING OR BRIQUETTE POWDER METALLURGY PROCESS

Compacting or briquetting is the process of converting loose powder into a "green compact" as it is called, of accurately defined size and shape. The briquette is considered fairly fragile, but it can be handled.

The compacting stage is carried out at room temperature in a die set-up on press. The die consists of a cavity , the shape of the desired part, but from two or ten times deeper, according to the material to be handled. Metal powder is poured into the cavity , and leveled off flush with the top of the die. The punches usually work from the top and the bottom of the die. Owing to interparticle friction , pressure applied from one direction will not be distributed uniformly throughout the part. This necessitates the use of the both top and bottom die. The dies are forced together under pressure into the die cavity and the powder is compressed to the desired shape to approximately one-third of its original volume. In addition to two punches , a core rod extending up through the lower punch and die barrel is also used for forming a hole in any cylindrical piece. Dies are made usually of high grade steel, finely finished and hardened, but carbide dies are used for long production runs.

The process used for compacting may be either mechanical or hydraulic or a combination of the two and the pressure used is from 100 to 1000 MN / m2 .

Compacting or Briquette powder metallurgy process

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Mechinopedia For Mechanical Engineers

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