組織和力學(xué)性能的影響
(1. 南京航空航天大學(xué) 材料科學(xué)與技術(shù)學(xué)院，南京 210016；
2. 華中科技大學(xué) 材料成形與模具技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，武漢 430074)
摘 要: 采用真空燒結(jié)工藝制備了Ti(C, N)基金屬陶瓷，通過(guò)XRD、TEM和SEM等手段研究碳納米管(CNTs)對(duì)金屬陶瓷組織和性能的影響。結(jié)果表明：與未加碳納米管的基體組織相比，添加CNTs的金屬陶瓷組織中具有“白芯−灰殼”結(jié)構(gòu)的小顆粒大大增加，金屬陶瓷晶粒逐漸細(xì)化且分布均勻；當(dāng)CNTs添加量(質(zhì)量分?jǐn)?shù))為0.5%時(shí)，Ti(C, N)基金屬陶瓷的硬度可達(dá)90.9HRA；金屬陶瓷的抗彎強(qiáng)度比未加碳納米管的試樣提高14.1%，可達(dá)2 180.7 MPa，其強(qiáng)化機(jī)制主要為細(xì)晶強(qiáng)化；金屬陶瓷的斷裂韌性比未加碳納米管的試樣提高18.5%，可達(dá)14.7 MPa·m1/2，CNTs對(duì)金屬陶瓷強(qiáng)韌化機(jī)制主要為橋聯(lián)作用、拔出效應(yīng)和裂紋偏轉(zhuǎn)作用。
關(guān)鍵字: Ti(C, N)基金屬陶瓷；碳納米管；顯微組織；力學(xué)性能
mechanical properties of Ti(C, N)-based cermets
（1. School of Materials Science and Technology, Nanjing University of
Aeronautics and Astronautics, Nanjing 210016, China;
2. State Key Laboratory of Dies and Mould Technology, Huazhong University of
Science and Technology, Wuhan 430074, China）
Abstract:Ti(C, N)-based cermets with CNTs addition were produced by vacuum sintering. The effects of carbon nanotubes (CNTs) addition on the microstructure and mechanical properties of Ti(C, N)-based cermets were studied by X-ray diffractometry (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results show that, compared with the base microstructure of cermets without CNTs addition, the grains of the cermets with CNTs addition are refined gradually and distributed homogeneously, and the amount of “white core-gray rim” increases. When the CNTs addition (mass fraction) is 0.5%, the hardness of the cermets is up to 90.9HRA, the transverse rupture strength (TRS) of the cermets is 2 180.7 MPa, which is about 14.1% higher than that of the cermets without CNTs addition, and the reinforcement mechanism of the cermets is caused by fine-grain strengthening. The fracture toughness (KIC) of the cermets with 0.5% CNTs addition is 14.7 MPa·m1/2, which is about 18.5% higher than that of the cermets without CNTs addition. The toughening mechanism of the cermets with CNTs addition is caused by crack bridging, pull-out mechanism and crack deflection.
Key words: Ti(C, N)-based cermets; carbon nanotube; microstructure; mechanical property
