Improving iron compact green strength using powder surface modification

In powder metallurgy, green strength has important consequences for part pr oduction rates and product end quality. Mechanical interlocking and interpa rticle cold welding are the main mechanisms responsible for green strength. These mechanisms are affected by compaction pressure, temperature, amount of lubricant and additives admired to the powder, and surface characteristi cs of the powder. The present paper describes the effect of iron powder sur face modification on the green strength of compacted specimens. The green p roperties of compacts fabricated from iron powder treated with diluted sulp huric acid and coated with copper by a non-catalytic displacement plating m ethod are presented. The results indicate that surface modifications strong ly influence the green strength of the compacts. PM/0831 (C) 1999 IoM Commu nications Ltd.