(昆明貴金屬研究所 稀貴金屬綜合利用新技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，昆明 650106)
摘 要: 利用化學(xué)鍍法對(duì)MWCNTs鍍銀并通過(guò)高能球磨制備MWCNTs/Ag復(fù)合粉末，然后采用粉末冶金法制備MWCNTs增強(qiáng)Ag復(fù)合材料，利用掃描電鏡對(duì)復(fù)合粉末的形貌以及復(fù)合材料中MWCNTs的分布進(jìn)行分析，研究MWCNTs含量對(duì)MWCNTs/Ag復(fù)合材料力學(xué)性能的影響。結(jié)果表明：球磨后Ag顆粒聚集形成二次大顆粒，隨著MWCNTs含量增加，顆粒聚集程度提高。MWCNTs體積分?jǐn)?shù)達(dá)到10%后，MWCNTs/Ag復(fù)合材料中MWCNTs團(tuán)聚嚴(yán)重；MWCNTs體積分?jǐn)?shù)增大，復(fù)合材料強(qiáng)度、硬度先增大后減小，體積分?jǐn)?shù)為8%時(shí)力學(xué)性能最佳，抗拉強(qiáng)度和屈服強(qiáng)度分別達(dá)到297MPa和245MPa，硬度HV0.1為80.1。復(fù)合材料表現(xiàn)出明顯的塑性斷裂特征，斷裂面形成了較多的韌窩，且存在明顯的MWCNTs拔出現(xiàn)象，說(shuō)明MWCNTs起到載荷傳遞和增強(qiáng)作用。
關(guān)鍵字: 碳納米管；化學(xué)鍍；力學(xué)性能；復(fù)合材料
（State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals,
Kunming Institute of Precious Metals, Kunming 650106, China）
Abstract:Multi-walled carbon nanotubes (MWCNTs) were coated by silver using chemical plating, MWCNTs/Ag composite powders were fabricated by high energy ball milling, and MWCNTs reinforced silver composites were obtained with powder metallurgy method. Morphologies of the composite powder and distribution of MWCNTs in the composite were analyzed by scanning electron microscopy. The effect of the MWCNTs content on the mechanical properties of the composites was studied. The results show that Ag particles gather to larger secondary particles after ball milling and the degree of aggregation increases with the increase of MWCNTs content. The MWCNTs present severe aggregation in the composites when the volume fraction of MWCNTs exceeds 10% (volume fraction). With the increase of the volume fraction of MWCNTs, strength and hardness of the composite first increase and then decrease. The composite containing 8% MWCNTs exhibits optimal mechanical properties with tensile strength of 297 MPa, yield strength of 245 MPa, and hardness of 80.1 HV0.1. The MWCNTs/Ag composite shows obvious plastic fracture with many dimples on the fracture surface. Pull-out of the MWCNTs illustrates the load transferring and strengthening effect of MWCNTs.
Key words: carbon nanotube; chemical plating; mechanical property; composite
