Cu被覆W複合粉末の焼結特性

抄録

30 mass%Cu coated W composite powders were produced by fluidized bed electroplating process. The sintering properties and the hardness of sintered compacts were investigated in comparison with mixed powders of tungsten and copper powders.
Tungsten powders of 0.7, 8 and 25 μm were prepared and each particle was coated with copper by the above process. The same tungsten powders and a pure copper powder of less than 43μm were mixed in order to compare the properties with those of composite powders. The powders were compacted at 294 MPa and sintered for 1 h at 1 173 K or 1 423 K in hydrogen. The relative density of compacts was investigated in relation to tungsten particle size and source powders ; i.e., composite or mixed powder. The microstructure of sintered compacts was investigated by EPMA and the hardness was measured.
Composite powder compacts sintered at 1 423 K showed higher relative density and much larger densification parameter than mixed powder compacts. The microstructure of composite powder compacts contained more homogeneously and finely dispersed copper than that of mixed powder compacts. Composite powder compacts showed higher hardness than mixed powder compacts.