Development and manufacture of brazed sintered part for wear resistant application

Paper i proceeding, 2009

To replace a conventionally machined and brazed component the manufacture of a sintered cog-wheel Cu-brazed to a steel cup has been studied. The sintered steel is fabricated from water-atomized 0.85% Mo steel powder admixed with 3% Cu-powder and 0.8% graphite to a green density of 7.0 g/cm3 followed by sintering at 1120°C for 30 min in nitrogen-bearing atmosphere with carbon control at -65°C dew point. After sintering, brazing and partial Cu infiltration in endogas preceded the final oil hardening, which through hardened the material to 680 ± 30 HV10. Component field testing showed that the sintered parts only experienced mild abrasive wear, thereby surpassing the required life time performance. Studies of different field tested parts showed that failure or too short life time was associated with brazing problems and not to the performance of the sintered part itself further demonstrating the potential of the studied sintered part assembly.