Introduction

POWDER METAL COMPACTING PRESSES, equipped with appropriate tooling, frequently are used for producing P/M components. Although commonly called P/M presses, use is not limited to the pressing of metal powders. Almost any alloy or mixture of materials produced in powder form can be compacted into suitable end products. The majority of components fabricated by P/M presses, in number of pieces and pounds of product produced, consists of compacted metals. Ferrous-base metals constitute the largest usage. Powder metallurgy compacting presses usually are mechanically or hydraulically driven, but they can incorporate a combination of mechanically, hydraulically, and pneumatically driven systems.

Table 1 summarizes some of the developments for P/M presses in the last 40 years. Other recent improvements in compaction technology include:

• Split-die techniques to make multilevel parts having different peripheral contours at different levels

• Punch rotation capability to facilitate production of helical gears and other helical shapes

• Higher compaction pressures by using stronger tool materials, advanced pressure control methods, and die wall lubricants

• Better process control with computerized tool motion monitoring

• Warm compaction and improved "segregation-free" powders with enhanced flow characteristics

Table 1 History of development in P/M presses

Years

Compacting press

1955-1959

Cam press, HP

1960-1964

Toggle press, MP

1965-1969

Large size HP (500 +), large size MP (500 +)

1970-1974

Multistepped MP, double die compacting press

1975-1979

Large size MP (750 +), tool holder quick change

1980-1989

NC press, multistepped HP (800 +), large size rotary press

1990-1994

Large size MP, automatic P/M manufacturing line

1995-present

Hybrid (mechanical/hydraulic) presses (800 tons)

HP, hydraulic press; MP, mechanical press; NC, numeric controlled

HP, hydraulic press; MP, mechanical press; NC, numeric controlled

Powder Metallurgy Presses and Tooling

Revised by John Porter, Cincinnati Incorporated

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