Preparation and characterization of Si3N4/(W, Ti)C nano-composite ceramic tool materials

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 596; pp. 255 - 263
• Main Authors: Tian, Xianhua, Zhao, Jun, Zhu, Ningbo, Dong, Ying, Zhao, Jiabang
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 24.02.2014; Elsevier
• Subjects: (W, Ti)C; Applied sciences; Ceramic tools; Composite materials; Cross-disciplinary physics: materials science; rheology; Deflection; Exact sciences and technology; Fractures; Hardness; Materials science; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Methods of nanofabrication; Microstructure; Nanocomposites; Nanostructure; Other materials; Physics; Si3N4; Silicon nitride; Sintering; Specific materials; Toughening and strengthening mechanisms; Transgranular fracture; Mechanical properties; Si3N4; Nanocomposites; Microstructure; (W, Ti)C; Toughening and strengthening mechanisms; Strengthening; Composite material; N; Hardening; Nanometer scale; Nanocomposite; Rupture strength; Ceramic materials; Nanomaterial synthesis; Branching; Transgranular fracture; Nanostructure; Hardness; Intergranular fracture; Fracture toughness; Transgranular cracking; Bending strength; Crack bridging; Hot pressing; Experimental result; Sintering; Si; Crack
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2013.12.065

Si3N4-based composite ceramic tool materials reinforced with nanoscale Si3N4 and microscale (W, Ti)C were fabricated by hot pressing and sintering technology. The flexural strength, fracture toughness and hardness of the sintered composites were tested and the microstructure and indention cracks were observed. The experimental results showed that the Si3N4/(W, Ti)C nanocomposites containing 18vol% of nanoscale Si3N4 and 20vol% of microscale (W, Ti)C, which were sintered under a pressure of 30MPa at 1700°C in vacuum condition for 45min, had the optimum comprehensive mechanical properties. The appropriate addition of microscale (W, Ti)C and nanoscale Si3N4 accelerated the formation of elongated β-Si3N4 grains and contributed to the improvement of mechanical properties. The strengthening and toughening mechanisms for the Si3N4/(W, Ti)C composite ceramic tool materials was a synergistic effect of intergranular and transgranular fracture, crack bridging, deflection and branching.