Microstructure and properties of La2O3 doped W composites prepared by a wet chemical process

Abstract La 2 O 3 /W composite powders were prepared by a wet chemical method,using ammonium metatungstate (AMT) and lanthanum oxides (La 2 O 3 ) as raw materials. La 2 O 3 /W composite materials were obtained by sintering the powder compacts at 2200 °C. The La 2 O 3 /W composite powders were characterized by X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM) coupled with energy dispersive spectrum (EDS) and microstructure of the La 2 O 3 /W composites was characterized by SEM and EDS. The results showed that the La 2 O 3 /W composite powders have polyhedral shape with particle size of 100–200 nm and some La 2 O 3 particles were wrapped up by tungsten particles. The highest relative density of 96.93% was obtained for the composites containing 0.6 wt% La 2 O 3 . Maximum bending strength and Rockwell hardness reach 434 MPa and 70.3HRA, respectively, for the 0.6%La 2 O 3 /W composites. Scanning electron microscopy observations reveal that the La 2 O 3 -W core-shell structure still remains in the sintered La 2 O 3 /W composites.