中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 2 February 2020 |
（1. Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria 0001, South Africa;
2. Department of Electrical Engineering, Tshwane University of Technology, Pretoria 0001, South Africa;
3. Department of Metallurgical and Materials Engineering, University of Nigeria, Nsukka 410001, Nigeria;
4. Department of Chemical, Materials and Metallurgical Engineering, Botswana International University of Science and Technology, Palapye 12345, Botswana;
5. Department of Mechanical Engineering, University of Johannesburg, Johannesburg 2000, South Africa）
Abstract:This study aimed at improving the tribological and thermal properties of Al alloy using CNTs and Nb nanopowder as reinforcements and spark plasma sintering (SPS) as the fabrication method. The SPS was conducted at 630 °C, 30 MPa, 10 min, and 200 °C/min. The tribology test was run with ball-on-disc tribometer using steel ball as the counter body. And the thermal test was processed with thermogravimetric analyzer (TGA) and laser flash apparatus (LFA). Results showed that the addition of 8 wt.% CNTs and 8 wt.% Nb reinforcements respectively decreased the coefficient of friction (COF) of the composite by 79%. The wear volume of the composite was decreased by 23%, and so was the wear rate. However, the thermal conductivity of the composite was equally improved by 44%. The tribology improvement was stimulated by a C film generated by CNTs and a protective Nb2O5 formed by Nb nanopowder. The thermal conductivity was improved by the grain refining property of Nb and the high thermal conductivity of CNTs. Therefore, these results indicated that Al-CNTs-Nb composite is a robust material for high transmission conductor capable of reducing sag and ensuring the durability of the composite.
Key words: tribology; thermal conductivity; spark plasma sintering; Al-CNTs-Nb composite; coefficient of friction
