Densification of B4C nanopowder with nanograin retention by spark-plasma sintering

摘要: Densification of a commercially available B4C nanopowder by spark-plasma sintering (SPS) with nanograin retention was investigated, emphasis on elucidating the potential both single-step and two-step SPS cycles as well effect pre-sintering annealing treatments nanopowders. It found that does not allow suitable processing window to obtain near-fully-dense nanostructured ceramics from as-received nanopowder, cause being attributable boria impurities producing coarsening. Pre-sintering eliminate thus facilitating densification SPS, but at expense grain growth. Two-step overcomes these drawbacks approach (both without treatments), enabling desired (but nonetheless certain size heterogeneity). also resulting are superhard toughened, highly desirable attributes in contact-mechanical tribological applications.