Spark plasma sintering versus hot pressing – densification, bending strength, microstructure, and tribological properties of Ti5Al2.5Fe alloys

ABSTRACT

Ti5Al2.5Fe alloys were fabricated by the spark plasma sintering (SPS) and hot pressing (HP) pressure-assisted sintering techniques from pre-alloyed powders with a particle size of about 200 μm. The powders were sintered at 850 °C for two different holding times (5 and 8 min) and heating rates (50 and 150°C min⁻¹) at 25 MPa. The maximum relative densities were 99.70 and 98.78% for SPS and HP samples, respectively. All the alloys prepared by the SPS process had significantly higher bending strengths (1825–2074 MPa) than the alloys prepared by the HP process (648–1330 MPa). A decrease in the heating rate from 150 to 50°C min⁻¹ enhanced the wear resistance of the Ti5Al2.5Fe alloys prepared by both the SPS and HP processes.

KEYWORDS:

• Ti5Al2.5Fe
• spark plasma sintering
• hot pressing
• mechanical properties

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Ridvan Yamanoglu was born in Bilecik and he graduated from the Kocaeli University, Izmit, Department of Metallurgical and Materials Engineering in 2002. He received his M.Sc. degree in 2005 and his PhD in 2011 from the Kocaeli University. He has been working at the same university since 2002. He was awarded by Turkish Scientific Council during his PhD. He studied his PhD at San Diego State University with Randall M. German and Eugene A. Olevsky. He also studied at the same university with Dr. Eugene Olevsky in 2014. Dr. Yamanoglu published several journal and conference papers and attended 4 international course on powder metallurgy.

Ismail Daoud received his M. Eng. degree in Materials Science and Engineering in 2011 from Boumerdes University, Boumerdes, Algeria. He is currently a PhD student in Materials science and Engineering department, University of Science and Technology HOUARI BOUMEDIENE, Algiers, Algeria. His research interests are Titanium alloys, liquid phase sintering, metal matrix composites, image analysis, and tribology.

Eugene Olevsky is Distinguished Professor of Mechanical Engineering and Associate Dean for Graduate Studies and Research at the College of Engineering of the San Diego State University, USA. Dr. Olevsky is the Director of the San Diego State University Powder Technology Laboratory. Eugene Olevsky is the author of over 500 scientific publications and of more than 150 plenary, keynote, and invited presentations in the area of sintering research. Prof. Olevsky has supervised scientific sintering studies of more than 100 post-doctoral, graduate, and undergraduate students. Prof. Olevsky is a Fellow of the American Ceramic Society, a Fellow of the American Society of Mechanical Engineers, Humboldt Fellow; he is a Full Member of the International Institute of Science of Sintering. Dr. Olevsky's most recent research is focused on field-assisted sintering techniques and sintering-assisted additive manufacturing.

Additional information

Funding

This work was supported by Scientific Research Projects Unit of Kocaeli University: [Grant Number 2015/042] and US Department of Energy, Materials Sciences Division: [Grant Number DE-SC0008581] through the Powder Technology Laboratory at the San Diego State University.