(1. 三峽大學(xué) 材料與化工學(xué)院，宜昌 443002；
2. 南京航空航天大學(xué) 材料科學(xué)與技術(shù)學(xué)院，南京 210016)
摘 要: 通過(guò)真空液相燒結(jié)工藝制備不同粘結(jié)相含量和相組成的Mo2FeB2基金屬陶瓷，并用壓痕法測(cè)量其斷裂韌性，研究粘結(jié)相含量和相組成對(duì)Mo2FeB2基金屬陶瓷斷裂韌性的影響。結(jié)果表明：粘結(jié)相含量對(duì)Mo2FeB2基金屬陶瓷的斷裂韌性具有一定影響，當(dāng)粘結(jié)相含量(質(zhì)量分?jǐn)?shù))由27%增加到37%時(shí)，斷裂韌性從12.8 MPa·m1/2提高到了17.3 MPa·m1/2；與粘結(jié)相含量的影響相比，粘結(jié)相相組成對(duì)Mo2FeB2基金屬陶瓷的斷裂韌性具有更加顯著的影響，當(dāng)粘結(jié)相為鐵素體時(shí)，金屬陶瓷的斷裂韌性為28.5 MPa·m1/2，增加了約一倍；硬質(zhì)相顆粒與粘結(jié)相的沿晶斷裂，尤其是粘結(jié)相的撕裂對(duì)其斷裂韌性的增加起重要的貢獻(xiàn)。
關(guān)鍵字: Mo2FeB2基金屬陶瓷；粘結(jié)相含量；粘結(jié)相組成；斷裂韌性
（1. College of Mechanical and Material Engineering, Three Gorges University, Yichang 443002, China
2. College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China）
Abstract:A series of Mo2FeB2 based cermets with different binder phase contents and compositions were fabricated by liquid phase sintering. The fracture toughness was measured by the indentation method, and the effects of binder phase contents and compositions on fracture toughness of Mo2FeB2 based cermets were investigated. The results show that the fracture toughness increases from 12.8 MPa·m1/2 to 17.3 MPa·m1/2 with an increase of binder phase content (mass fraction) from 27% to 37%. In addition, the effect of the binder phase compositions on the fracture toughness of Mo2FeB2 based cermets is more obvious compared with that of the binder phase contents. The fracture toughness improves to 28.5 MPa·m1/2 when the binder phase is ferrite, which is twice higher than that of martensite binder phase. The toughening mechanism is characterized by dimple rupture across the binder and near a binder/hard phase interface.
Key words: Mo2FeB2 based cermets; binder phase content; binder phase composition; fracture toughness
