Microstructures and mechanical properties of in situ TiC-β-Ti-Nb composites with ultrafine grains fabricated by high-pressure sintering

作者：Liu, Z.; Zhang, D. C.^*; Gong, L. J.; Lin, J. G.^*; Wen, Cuie

来源：Scientific Reports, 2018, 8(1): 9496.

DOI：10.1038/s41598-018-27535-6

• METAL-MATRIX COMPOSITES
• PARTICLE-SIZE
• TITANIUM
• TEMPERATURE
• BEHAVIOR
• POWDERS

In this study, an in situ beta-Ti-Nb composites reinforced with TiC particles with an ultrafine grain size were fabricated using a powder metallurgical (PM) method. The microstructures and mechanical properties of the composites were characterized using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and compression tests. TiC particles were formed in the ball-milled powders after annealing at 600 degrees C due to a chemical reaction between stearic acid and titanium. Using high-pressure sintering (HPS) on an apparatus with six tungsten carbide anvils, a fully dense beta-Ti-Nb composite reinforced with fine in situTiC particles was obtained. The TiC particles exhibit particle sizes of similar to 500 nm, uniformly distributed in the composite matrix, which had grain sizes of similar to 600 nm. Thus, the TiC-beta-Ti-Nb composite show very high compression yield strength and relatively high plasticity contributed by grain refinement and TiC particles strengthening. The composite with 45 vol.%TiC exhibited excellent mechanical properties, with a yield compressive strength of 1990 MPa and plastic strain of 9.12%. More over, a modified rule-of-mixture (ROM) was presented to describe the combined strengthening effect of grain refinement and TiC particles.

• 出版日期2018-6-22
• 单位湘潭大学