Fabrication and mechanical properties of CNT/Al composites via shift-speed ball milling and hot-rolling
- PDF / 1,039,880 Bytes
- 11 Pages / 584.957 x 782.986 pts Page_size
- 62 Downloads / 232 Views
Fabrication and mechanical properties of CNT/Al composites via shift-speed ball milling and hot-rolling Chao Yuan1, Zhanqiu Tan1,a), Genlian Fan1, Mingliang Chen2, Quan Zheng2, Zhiqiang Li1,b) 1
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China 2 Shanghai Key Laboratory of Spacecraft Mechanism, Aerospace System Engineering Shanghai, Shanghai 201108, China a) Address all correspondence to these authors. e-mail: [email protected] b) e-mail: [email protected] Received: 21 March 2019; accepted: 10 June 2019
Flat products of carbon nanotubes (CNTs) reinforced Al matrix composites were fabricated using flake powder metallurgy via shift-speed ball milling and hot-rolling. The evolution of CNTs during preparation and the final distribution in the Al matrix were investigated, and the effect of CNT content on mechanical properties were discussed. Due to the combined effect of uniform dispersion of CNTs, structural integrity, interfacial bonding and directional alignment, the balance between high strength and ductility was successfully achieved in the annealed rolled composites with 1.5 wt% CNT addition, with the value of 382.6 MPa in tensile strength and 9.8% in fracture ductility. The load transfer strengthening was the main mechanism of the strength enhancement with CNTs addition. In addition, a strong rotated cube {001}〈110〉 texture was found in the final flat product of rolled composites. This study provides an effective route to produce and improve the mechanical properties of CNT/Al flat products.
Introduction Carbon nanotubes (CNTs) have attracted increasing attention as excellent reinforcements in Al matrix composites in the past two decades, due to their low density and excellent mechanical properties [1, 2]. The CNT/Al composites have great potential in the lightweight structural application. However, due to the large specific surface and strong van der Waals forces, raw CNTs used for the reinforcements usually tend to be clustered in the matrix, which results in a sharp decrease of ductility. So far, to obtain CNT/Al composites with high strength, stiffness and ductility, great efforts have been made by improving the CNT dispersion, structural integrity and interfacial bonding [2]. And a few methods, such as powder metallurgy (PM) [3, 4, 5], severe plastic deformation (SPD) [6, 7, 8], semi-solid powder processing [9] or induction melting [10], in situ chemical vapor deposition (CVD) [11, 12], electrochemical deposition (ED) [13], and nanoscale dispersion (NSD) [14], have been explored to fabricate CNT/Al composites. However, dispersion by mechanical methods, such as high energy ballmilling [4] and SPD [7], would cause severe structural damage due to the strong impact force from milling balls or the shear
ª Materials Research Society 2019
stress during SPD, which result in the decrease of strengthening efficiency and ductility. Semi-solid powder processing [9] or induction melting [10] would also cause severe damage
Data Loading...
