Effect of Sintering Temperature on Properties of CNT/Al Composite Prepared by Capsule-Free Hot Isostatic Pressing Technique

• DOI: 10.1007/s12666-016-0886-8
• Publication Date: 2016-05-11T06:58:36Z
• Authors: Pham Van Trinh; Nguyen Van Luan; Phan Ngoc Minh; Doan Dinh Phuong
• Keywords: Hot isostatic pressing; Relative density; Hot pressing

Carbon nanotube (CNT)/Al composite powders were prepared by high energy ball milling technique. CNTs were well dispersed in Al matrix but the graphite structure of CNTs was significantly damaged during the mixing process. Dense composite was prepared by capsule free hot isostatic pressing technique. The best sintering temperature was determined to be 620 °C, at which relative density of sintered specimens increased to 92 % and decreased with the increase of CNT content due to the formation of CNT clusters. Microhardness of the composite could be improved by increasing CNT content up to 1 wt% with the highest value of 56.7 HV which was nearly two times higher than that of pure Al. Electrical resistivity was increased in proportion to the CNT content. The increase of resistivity was due to the effect of porosity, electron scattering at particle boundaries and existence of oxidation phase.