Effect of Carbon Content on Mechanical Properties of Boron Carbide Ceramics Composites Prepared by Reaction Sintering

• Published in: Materials Vol. 15; no. 17; p. 6028
• Main Authors: Sha, Wenhao, Liu, Yingying, Zhou, Yabin, Huang, Yihua, Huang, Zhengren
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2022; MDPI
• Subjects: Activated sintering; Analysis; Boron; Boron carbide; Carbides; Carbon; Carbon content; Ceramic materials; Ceramics; Composite materials; composites; elastic modulus; Flexural strength; Grain boundaries; Grinding tools; Hot pressing; Mechanical properties; Modulus of elasticity; Particle size; Phase composition; Phase distribution; Plasma sintering; reaction sintering; Silicon carbide; Sintering; vickers hardness; China; United States > US; Japan
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma15176028

In this study, different reaction-bonded boron carbide (RBBC) composites with a free carbon addition from 0 to 15 wt% were prepared, and the effect of the carbon content on the mechanical properties was discussed. With the free carbon addition increase from 0 to 15 wt%, the residual silicon content in the RBBC composite decreased first and then increased. Meanwhile, the strength of the RBBC composite improved first and then worsened. In the RBBC composite without free carbon, the B4C grains are obviously dissolved, the grains become facet-shape, and the grain boundary becomes straight. The microstructure of the composite was tested by SEM, and the phase composition of the composite was tested by XRD. The RBBC composite with the addition of 10 wt% free carbon has the highest flexural strength (444 MPa) and elastic modulus (329 GPa). In the composite with a 10 wt% carbon addition, the phase distribution is uniform and the structure is compact.