Fabrication and characterization of W-Cu functionally graded material by spark plasma sintering process

In this study, seven-layered W/Cu functionally graded material (FGM) (100 W, 80W-20Cu, 60W-40Cu, 50W-50Cu, 40W-60Cu, 20W-80Cu, 100Cu, by wt %) were fabricated by a spark plasma sintering process (SPS). The influences of sintering temperature on microstructure, physical and mechanical properties of the sintered bulk FGM were investigated. Results indicated that the graded structure of the composite densified after the SPS process and interfaces of the layers are clearly visible. All of the layers had a very high relative density, thereby indicating their densification and excellent sintering behavior. SEM and EDX study of the bulk sample cross-section reveal that the graded structure can be retained up to sintering temperature of 1050 °C. In addition fine microstructure within each layer with good interface bonding was also observed. Sample sintered at 1050 °C exhibited excellent mechanical and physical properties (hardness 239 ± 5 Hv and relative density of 90.5%). The result demonstrates that SPS is a promising and more suitable process for fabrication of W-Cu functionally graded materials.