Optimisation of spark plasma sintering parameters of Al-CNTs-Nb nano-composite using Taguchi Design of Experiment

Optimisation of process parameters is usually undertaken to achieve more efficient and cost-effective process conditions. This work deals with the optimisation of spark plasma sintering process parameters which include sintering temperature, pressure, dwell time and heating rate for the development of Al-CNTs-Nb nano-composite. Taguchi Design of Experiment (DOE) was used to design the sintering operation, while analysis of variance (ANOVA) was used to investigate the contribution of the factor variables to the response variables of density and micro-hardness. The admixed powders were consolidated as designed with SPS machine, while the sintered compacts were characterised using optical microscope, Vickers hardness tester and Archimedes-based density tester. The results obtained were a maximum density of 2.68 g cm ⁻³ (99.3% relative density) and maximum micro-hardness of 38.57 HV (0.37 GPa), while the optimal SPS parameters were sintering temperature of 630 °C, pressure of 30 MPa, dwell time of 10 min and heating rate of 200 °C/min. This work has achieved a 20% improvement in micro-hardness which is good for so many engineering applications.