Fundamentals of fibre formation during melt extraction

Xing

et al. 2010

Metall Mater Trans A

Amorphous Co 68.15 Fe 4.35 Si 12.25 B 15.25 wires with smooth surface and circular cross section were fabricated by melt extraction technology using a copper wheel with a knife-edge cross section angle of 60 deg. The effect of some process parameters such as wheel circumference velocity, molten alloy feed rate, and temperature on the geometry and weight, i.e., melt extracted layer thickness, of wire was examined carefully. An optimum process parameter to produce highquality circular wires was presented. A high resolution CCD video camera recorder was used to monitor the changing of the surface shape of molten alloy contacting the wheel tip under different conditions. It was found that the mechanism of the wire formation during the optimum process condition was controlled by the momentum mechanism, while in the low wheel speed region, heat transfer turned out to be a dominant factor. Some characteristics of the circular wires such as amorphous nature and tensile strength were also studied.

Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of Melt-Extracted Co-Based Amorphous Wires

Xing

et al. 2010

Metall Mater Trans A

“…After manufacturing of the fibers, they are usually dry deposited and sintered to yield highly porous structures. More processing details can be found elsewhere …”

Section: Introductionmentioning

confidence: 99%

Highly Porous Magnesium Alloy Structures and Their Properties Regarding Degradable Implant Application

et al. 2013

Magnesium alloys offer excellent properties with regard to application as degradable implant. For bone implants, it is often desirable to use porous materials. However, the preparation of high-porosity magnesium implants has been difficult so far. The present study uses melt extracted magnesium fibers as the starting material for the sintering of highly porous magnesium bodies, i.e., from alloys MgY4 (W4) and MgY2Zn1CaMn (WZ21). Single short fibers of these alloys with an equivalent diameter between 100 and 250 mm and a length of 4-8 mm are manufactured by melt extraction. Thermodynamic calculations are used to determine the best conditions for liquid phase sintering of these Mg alloys. As no organic or other substances are needed in the process, it is possible to obtain high-purity, high-porosity (up to 75%) bodies with exclusively open porosity. Metallographic studies as well as mechanical and corrosion testing experiments complete this work.

Applied Physics Letters

“…S1). 31 During meltextraction, the cooling rate of the extracted filaments may reach 10 4 -10 5 K/s, 32 implying a grain refinement in the asextracted microwires after solidification, as illustrated in Fig. 1(a).…”

mentioning

confidence: 99%

Magnetostructural coupling and magnetocaloric effect in Ni-Mn-Ga-Cu microwires

Zhang

Qian

Zhang

et al. 2016

Ni-Mn-Ga-X microwires were produced by melt-extraction technique on a large scale. Their shape memory effect, superelasticity, and damping capacity have been demonstrated. Here, the excellent magnetocaloric effect was revealed in Ni-Mn-Ga-Cu microwires produced by melt-extraction and subsequent annealing. The overlap of the martensitic and magnetic transformations, i.e., magnetostructural coupling, was achieved in the annealed microwires. The magnetostructural coupling and wide martensitic transformation temperature range contribute to a large magnetic entropy change of −8.3 J/kg K with a wide working temperature interval of ∼13 K under a magnetic field of 50 kOe. Accordingly, a high refrigeration capacity of ∼78 J/kg was produced in the annealed microwires.