|Feb. 18, 2020, 16:00|
|Campus North, INT, 0-167|
"Mechanical properties of multi-phase high-entropy alloys"
Introduction: Dr. Julia Ivanisenko
In a quest to develop new materials with enhanced properties, a novel class of material systems called as “high-entropy alloys (HEAs)” have emerged recently, challenging the conventional alloy making principles. This concept gives a “near-infinite” compositional space for exploration which was untouched till now. Therefore, it is also expected that unprecedented properties would be exhibited by these materials. Our efforts at University of Hyderabad, India include development of various classes of these materials by adding different alloying elements in equi-atomic proportion and understanding the resultant mechanical properties vis-à-vis structural/microstructural features. Ball milling coupled with spark plasma sintering (SPS) as well as vacuum arc melting have been used to fabricate various multi-phase HEA systems. Ball milling has resulted in either single/dual phase structures whereas multi-phase structures have been realized while heating the samples as part of sintering/homogenization. These multi-phase structures have resulted in interesting mechanical properties w.r.t. hardness, strain rate sensitivity, activation volume, fracture toughness etc. Development of some of our HEA systems was inspired by conventional super-alloys such as Haynes 188. Detailed characterization has been done using X-ray diffraction and electron microscopy. Mechanical properties were evaluated by micro indentation and high throughput nano-indentation at room temperature. This talk would address the relationship between microstructural features and the corresponding indentation based mechanical properties of different HEA systems. It was broadly observed that a multi-phase structure is desirable to have a balanced mechanical property in various alloy systems.
|This event is part of the eventgroup INT Talks|
Dr. Julia Ivanisenko
Institute of Nanotechnology (INT)
Karlsruhe Institute of Technology (KIT)
Mail:julia ivanisenko∂kit edu