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

La2O3/W composite powders were prepared by a wet chemical method,using ammonium metatungstate (AMT) and lanthanum oxides (La2O3) as raw materials. La2O3/W composite materials were obtained by sintering the powder compacts at 2200 degrees C. The La2O3/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 La2O3/W composites was characterized by SEM and EDS. The results showed that the La2O3/W composite powders have polyhedral shape with particle size of 100-200 nm and some La2O3 particles were wrapped up by tungsten particles. The highest relative density of 96.93% was obtained for the composites containing 0.6 wt% La2O3. Maximum bending strength and Rockwell hardness reach 434 MPa and 70.3HRA, respectively, for the 0.6%La2O3/W composites. Scanning electron microscopy observations reveal that the La2O3-W core-shell structure still remains in the sintered La2O3/W composites.