Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7210506 | Rare Metal Materials and Engineering | 2017 | 4 Pages |
Abstract
Tapered Cu50Zr42Al8 alloy with good glass-forming ability was fabricated by copper mould suction casting. Cubic AlCu2Zr and B2-ZrCu, thermal-induced martensitic B19'-ZrCu phases form on the glass matrix along the radial direction structure. Size effects on micro-mechanical properties and a unique crack healing behavior were studied. Micro-hardness of monolithic bulk metallic glass (BMG) displays “smaller is softer” trend, that is, the softer surface and the harder center. Whereas the lager size composites possess a softer center and a harder surface, due to the integrative action of the secondary phases. Amorphous matrix is toughened by TRIP (transition induced plasticity) effect of shape-memory phase as well as weakened and embrittled by AlCu2Zr crystal. After annealing, self-healing of Vickers indentation crack occurs as the thermoelastic transformation of shape-memory crystals. As loading, stress-induced martensites transform from B2 to B19', along with volume expansion. Annealed upon the reverse transformation temperature, B19' to B2 transform accompanied by a volume shrinkage, and a restoring force from the structure stress is set up to drive the crack closure.
Related Topics
Physical Sciences and Engineering
Engineering
Mechanics of Materials
Authors
Yuan Xiaopeng, Zhao Yanchun, Kou Shengzhong, Zhao Zhiping, Li Chun-yan, Yuan Zizhou,