|Cite this article as:|
|Weiqiang Hu, Fengming Gong, Shaocun Liu, Jing Tan, Songhua Chen, Hui Wang, and Zongqing Ma, The microstructure refinement and second phase particle regulation of Mo–Y2O3 alloys by minor TiC additive, Int. J. Miner. Metall. Mater.,(2022). https://doi.org/10.1007/s12613-022-2462-z|
The oxide dispersion strengthened Mo alloys (ODS-Mo) prepared by traditional ball milling and subsequent sintering technique generally possess comparatively coarse Mo grains and large oxide particles at Mo grain boundaries (GBs), which obviously suppress the corresponding strengthening effect of oxide addition. In this work, the Y2O3 and TiC particles were simultaneously doped into Mo alloys using ball-milling and subsequent low temperature sintering. Accompanied by TiC addition, the Mo-Y2O3 grains are sharply refined from 3.12 μm to 1.36 μm. In particular, Y2O3 and TiC can form smaller Y-Ti-O-C quaternary phase particles (~ 230 nm) at Mo GBs compared to single Y2O3 particles (~ 420 nm), so as to these new formed Y-Ti-O-C particles can more effectively pin and hinder GBs movement. In addition to Y-Ti-O-C particles at GBs, Y2O3, TiOx and TiCx nanoparticles (< 100 nm) also exist within Mo grains, which significantly different from traditional ODS-Mo. The appearance of TiOx phase indicates that some active Ti within TiC can adsorb oxygen impurities of Mo matrix to form new strengthening phase, thus strengthening and purifying Mo matrix. Furthermore, the relative density of pure Mo, Mo-Y2O3 and Mo-Y2O3-TiC alloys possesses similar values (97.4~98.0%). More importantly, the Mo-Y2O3-TiC alloys possess higher hardness (425 HV0.2) compared to Mo-Y2O3 alloys (370 HV0.2). Our work could provide a relevant strategy for the preparation of ultrafine Mo alloys by facile ball-milling.