A review on the formation and unique physical and mechanical properties of metallic glassy fibers(MGFs)with the diameter ranging from micro to nano scales fabricated by a supercooled liquid extraction method(SLEM)is g...A review on the formation and unique physical and mechanical properties of metallic glassy fibers(MGFs)with the diameter ranging from micro to nano scales fabricated by a supercooled liquid extraction method(SLEM)is given.The SLEM method,through driving metallic glass rods in their supercooled liquid region via superplasticity,can fabricate MGFs with precisely designed and controlled size and properties,high structural uniformity and surface smoothness and extreme flexibility.The SLEM method is efficient and the MGFs can be continuously prepared by this method.A parameter f based on the thermal and rheological properties of MG-forming alloys is proposed to control the preparation and size of the fibers.We show that the novel MGFs with superior properties may attract intensive scientific interests and propel more engineering and functional applications.展开更多
Bulk metallic glasses (BMGs) with large supercooled liquid region are promising materials for superplastic forming. In this paper, we demonstrate a microstructure-based strategy to pinpoint the composition with the la...Bulk metallic glasses (BMGs) with large supercooled liquid region are promising materials for superplastic forming. In this paper, we demonstrate a microstructure-based strategy to pinpoint the composition with the largest supercooled liquid region in La 86 x Al 14 Cu x (x=16 at%-20 at%) metallic glass system. By monitoring the changes in crystallization behavior of the glassy alloys with composition to search for the alloys exhibiting eutectic crystallization, the glassy alloys with the largest supercooled liquid region in the given alloy system can be found. The metallic glasses with Cu contents of 16 at%-19 at% exhibited two crystallization peaks, and the primary crystallization product was identified to be α-La by means of DSC, XRD and TEM. The increase in Cu content resulted in the decay of the primary crystallization peak and the increase in onset temperature of crystallization, leading to the enlargement of supercooled liquid region. By further suppressing the α-La primary crystallization with increasing Cu content up to 20 at%, the eutectic crystallization of α-La and LaCu 13 through one crystallization reaction occurred upon heating, where the largest supercooled liquid region of 65 K for La 66 Al 14 Cu 20 glassy alloy was located. This study indicats that, in a given glassy alloy system, a larger supercooled liquid region can be achieved by optimizing the alloy compositions to suppress the primary crystallization.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51271195 and 51171204)the National Basic Research Program of China(Grant No.2010CB731603)
文摘A review on the formation and unique physical and mechanical properties of metallic glassy fibers(MGFs)with the diameter ranging from micro to nano scales fabricated by a supercooled liquid extraction method(SLEM)is given.The SLEM method,through driving metallic glass rods in their supercooled liquid region via superplasticity,can fabricate MGFs with precisely designed and controlled size and properties,high structural uniformity and surface smoothness and extreme flexibility.The SLEM method is efficient and the MGFs can be continuously prepared by this method.A parameter f based on the thermal and rheological properties of MG-forming alloys is proposed to control the preparation and size of the fibers.We show that the novel MGFs with superior properties may attract intensive scientific interests and propel more engineering and functional applications.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50631010, 50771005 and 50771006)the National Basic Research Program of China (Grant No. 2007CB613900)
文摘Bulk metallic glasses (BMGs) with large supercooled liquid region are promising materials for superplastic forming. In this paper, we demonstrate a microstructure-based strategy to pinpoint the composition with the largest supercooled liquid region in La 86 x Al 14 Cu x (x=16 at%-20 at%) metallic glass system. By monitoring the changes in crystallization behavior of the glassy alloys with composition to search for the alloys exhibiting eutectic crystallization, the glassy alloys with the largest supercooled liquid region in the given alloy system can be found. The metallic glasses with Cu contents of 16 at%-19 at% exhibited two crystallization peaks, and the primary crystallization product was identified to be α-La by means of DSC, XRD and TEM. The increase in Cu content resulted in the decay of the primary crystallization peak and the increase in onset temperature of crystallization, leading to the enlargement of supercooled liquid region. By further suppressing the α-La primary crystallization with increasing Cu content up to 20 at%, the eutectic crystallization of α-La and LaCu 13 through one crystallization reaction occurred upon heating, where the largest supercooled liquid region of 65 K for La 66 Al 14 Cu 20 glassy alloy was located. This study indicats that, in a given glassy alloy system, a larger supercooled liquid region can be achieved by optimizing the alloy compositions to suppress the primary crystallization.
