Green Machining Of P/M Parts Using Enhanced Green Strength Lubricating Systems 2001-01-0399
P/M parts are often machined after sintering to meet tight dimensional tolerances or accommodate design features that cannot be molded during compaction. The development of new polymeric lubricants opens the possibility of machining P/M components prior to sintering, which could result in a considerable reduction of machining costs.
This study compares the green and ejection characteristics of binder-treated FC-0205 mixes containing either a new high green strength lubricating system or conventional EBS wax. The comparison was carried out on TRS specimens and gears pressed from 6.8 to 7.2 g/cm3 on laboratory and production scale presses. The influence of these lubricating systems on green machining was also determined on gear shape specimens pressed to 6.8 and 7.0 g/cm3. Results showed that mixes containing the new lubricating system exhibit similar compressibility and a better lubrication behavior than mixes admixed with the conventional EBS wax. Moreover, the green strength of gears produced with the new lubricating system was sufficiently high to enable machining in the green state.