Abstract: The influences of TiN additions on microstructure, mechanical properties and fracture behaviour of the SAF 2205-TiN composites were investigated. Automated spark plasma sintering machine (model HHPD-25, FCT GmbH Germany) was used to fabricate the composites. Characterization was performed using Scanning Electron Microscopy. Archimedes principle was used to evaluate the densities of the composites. Hardness (H) and elastic modulus (E) were investigated by nanoindentation using load 1 mN. The results obtained indicated that SPS process parameters were optimized at 1150 oC, 15 min and 100 oC/min. The microstructure revealed that the TiN particles have a general tendency to segregate at the grain boundaries. The hardness (H) and elastic modulus (E) values increased with TiN contents due to the hardening and stiffening effects of the TiN reinforcements. With increase in TiN content, the dimples on the fracture surfaces of the composites reduced drastically with only faint traces of the dimples left. A combination of ductile and brittle fractures is prevalent in the 6 and 8 % TiN.
Authors: Samuel Ranti Oke, Mahlatse R. Mphahlele, Oladeji Oluremi Ige, Oluwasegun Eso Falodun, Babatunde Abiodun Obadele, and Peter Apata Olubambi
Keywords: Spark Plasma Sintering (SPS); Duplex Stainless Steel (SAF 2205); Titanium Nitride (TiN); Microstructure; Fracture Behavior