| | 
Höganäs AB has been co-operating with Scania, a leading manufacturer of heavy trucks, to test the potential of various powder metal (P/M ) manufacturing methods for high-performance gears. Warm compaction and surface densification are two performance-enhancing processes that arehelping to push P/M technology towards the high strength and fatigue properties required for transmission gears. The study from Höganäs andScania compares the performance of gears produced by three different manufacturing routes: cold compaction, warm compaction and surface densification. Tests were carried out on a 20-tooth, 700g planetary gear used in the hub reduction unit of Scania heavy trucks and confirmed theperformance-enhancing qualities of warm compaction and surface densification. Warm compaction improves density and ensures excellent pore size distribution. Surface densification enhances the fatigue properties and the surface hardness allowing a virtual pore-free surface layeralong the gear tooth. The study also showed that, compared with cold compaction, warm compaction elevates tooth root fatigue performance byincreasing the density from 7.01g/cm³ to 7.44 g/cm³.
| |
