Insights into microscale fracture behavior of C14-CaMg2 and C15-CaAl2 Laves phase intermetallic compounds (14/08/23)
Speaker and Affliation:
Dr. Anwesha Kanjilal
Department of Structure and Nano- and Micro-mechanics of Materials,
Max-Planck-Institut für Eisenforschung, Düsseldorf.
When?
14th August, 2023 (Monday), 03:00 PM (India Standard Time)
Venue
KPA Auditorium, Department of Materials Engineering
Abstract
The Mg rich alloys of Mg-Al-Ca contain various intermetallic compounds such as the β-Mg17Al12 and the Laves phases of C14-CaMg2 and C15-CaAl2, which improve the mechanical properties of the alloy. These intermetallics are brittle at room temperature, but may undergo brittle to ductile transition with loss in strength, thereby limiting the high temperature performance of the alloy. So far, much of the fracture properties of the Laves phase intermetallics remain unknown. In this talk I will discuss the microscale fracture behavior of these Laves phases as a function of composition and temperature using in-situ nano- and micromechanical testing. Firstly, to understand the role of crystal orientation on fracture the potential crack planes were identified and corresponding fracture toughness of these planes was determined using nanoindentation and microcantilever fracture testing. For different crack plane orientations and Laves phase compositions, brittle fracture with low anisotropy in fracture toughness was observed. Subsequently, the effect of temperature on microscale fracture was investigated. Through high temperature nanoindentation the regime for change in deformation was identified, followed by indentation-based micro-pillar splitting at elevated temperatures to determine transition from brittle to ductile failure.