Chen, Y.Y., Yu, H.B., Zhang, D. & Chai, L.H. (2009). Effect of spark plasma sintering temperature on microstructure and mechanical properties of an ultrafine grained TiAl intermetallic alloy. Materials Science and Engineering: A, 525(1-2), 166-173.
Permanent Research Commons link: https://hdl.handle.net/10289/4134
The effect of spark plasma sintering (SPS) temperature on the microstructure and mechanical properties of a bulk solid ultrafine grained gamma TiAl alloy produced by SPS of an ultrafine structured Ti/Al composite powder with a nominal composition of Ti–47 at.%Al has been investigated. The Ti/Al composite powder was produced using high energy mechanical milling. It was found that an SPS temperature of 800 °C led to the completion of the reactions needed for reaching the phase equilibrium and formation of a nanostructure with grain sizes in the range of 50–100 nm. However, this SPS temperature was not sufficient to achieve a nearly full density of the compact or a high level of interparticle bonding. Increasing the SPS temperature from 800 to 900 °C caused a significant increase of the density and the level of interparticle bonding while still maintaining grain sizes of <500 nm. The bulk TiAl alloy produced under this condition had a good compression yield strength, fracture strength, bending strength and plastic strain to fracture of 1722, 1963, 610 MPa and 4%, respectively. Increasing the SPS temperature from 900 to 1100 °C caused significant coarsening of the TiAl grains which led to a clear decrease in yield strength and hardness and a slight increase in ductility.