Metallic glass formation is equivalent with the avoidance of crystallization during solidification. The glass forming ability is quantified by the critical cooling rate, the lowest cooling rate, which avoids crystallization. These rates are remarkably low, ranging 1-100 K/s for bulk metallic glasses, which are up to 12 orders of magnitude lower than required rates for pure metals. However, despite these low rates which suggest experimentally convenient time scales for processing, a robust fabrication that results in desirable properties that can be repeatedly be achieved in complex shapes of even the most processable bulk metallic glass formers remains a challenge.
In this talk, I will investigate the origin for this challenge and quantify the effects that deteriorate the mechanical properties on the way from a bulk metallic glass forming melt to a complexly shaped final article with desirable properties. Specifically, the effect of (partial) crystallization, cooling rate, flaws, and chemical composition will be quantified by fracture toughness measurements. This work revealed that thermoplastic-based processing methods are most promising to fabricate complex bulk metallic glass articles with consistently high performance.