2011 年 52 巻 608 号 p. 1017-1021
Functionally graded cemented carbide (FGCC) models with a hardness distribution are fabricated by combining the powder layer compaction (PLC) technique and CNC milling. In the fabrication of the FGCC model, powders of cemented carbide (WC) with different Co contents are combined by compaction and then the resulting green compact is sintered. The hardness is confirmed to change smoothly around the interface of the WC samples with different Co contents in the sintered FGCC models. To control the hardness distribution of the sintered FGCC models, the influences of fabrication conditions on Co diffusion and movement during sintering are examined. Presintering at temperatures higher than 600 °C is found to be effective for suppressing Co diffusion and movement. Furthermore, residual stress in the sintered FGCC die model is estimated. When the inner layer is presintered at 1300 °C, a compressive residual stress is confirmed to be induced in the inner layer of the sintered FGCC die model.