Journal of Materials Research and Technology Journal of Materials Research and Technology
J Mater Res Technol 2018;7:126-34 DOI: 10.1016/j.jmrt.2017.03.004
Original Article
Optimization of process parameters for spark plasma sintering of nano structured SAF 2205 composite
Samuel Ranti Okea,b,, , Oladeji Oluremi Igea,c, Oluwasegun Eso Faloduna, Babatunde Abiodun Obadelea, Mxolisi Brendon Shongwed, Peter Apata Olubambia
a Center for NanoEngineering and Tribocorrosion, School of Mining, Metallurgy and Chemical Engineering, University of Johannesburg, Doornfontein Campus, 2028 Johannesburg, South Africa
b Department of Metallurgical and Materials Engineering, Federal University of Technology Akure, Ondo State, Nigeria
c Department of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
d Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Pretoria, South Africa
Received 02 February 2017, Accepted 22 March 2017

This research optimized spark plasma sintering (SPS) process parameters in terms of sintering temperature, holding time and heating rate for the development of a nano-structured duplex stainless steel (SAF 2205 grade) reinforced with titanium nitride (TiN). The mixed powders were sintered using an automated spark plasma sintering machine (model HHPD-25, FCT GmbH, Germany). Characterization was performed using X-ray diffraction and scanning electron microscopy. Density and hardness of the composites were investigated. The XRD result showed the formation of FeN0.068. SEM/EDS revealed the presence of nano ranged particles of TiN segregated at the grain boundaries of the duplex matrix. A decrease in hardness and densification was observed when sintering temperature and heating rate were 1200°C and 150°C/min respectively. The optimum properties were obtained in composites sintered at 1150°C for 15min and 100°C/min. The composite grades irrespective of the process parameters exhibited similar shrinkage behavior, which is characterized by three distinctive peaks, which is an indication of good densification phenomena.

Spark plasma sintering, Duplex stainless steel (SAF 2205), Titanium nitride (TiN), Microstructure, Density, Hardness
J Mater Res Technol 2018;7:126-34 DOI: 10.1016/j.jmrt.2017.03.004