Factorial optimization of the effects of melt-spinning conditions on biodegradable as-spun aliphatic-aromatic copolyester fibers. III. Diameter, tensile properties, and thermal shrinkage

2011 ◽  
Vol 122 (2) ◽  
pp. 1434-1449 ◽  
Author(s):  
Basel Younes ◽  
Alex Fotheringham
Keyword(s):  
Tensile Properties ◽  
Melt Spinning ◽  
Thermal Shrinkage ◽  
Factorial Optimization

Structure and tensile properties of Nanoclay-Polypropylene fibers produced by melt spinning

2011 ◽  
Vol 121 (1) ◽  
pp. 410-419 ◽  
Author(s):  
Loganathan Rangasamy ◽  
Eunkyoung Shim ◽  
Behnam Pourdeyhimi
Keyword(s):  
Tensile Properties ◽  
Melt Spinning ◽  
Polypropylene Fibers

scholarly journals Effects of melt spinning parameters on polypropylene hollow fiber formation

2020 ◽  
Vol 15 ◽  
pp. 155892501989968
Author(s):  
Rebecca Ruckdashel ◽  
Eunkyoung Shim
Keyword(s):  
Tensile Properties ◽  
Hollow Fiber ◽  
Melt Spinning ◽  
Tensile Modulus ◽  
Fiber Spinning ◽  
Fiber Formation ◽  
Processing Conditions ◽  
Quench Rate ◽  
Fiber Structure ◽  
Spinning Speed

The objective of this research was to explore the effects of processing conditions on hollow fiber spinning, specifically to look at how differences in solidification impact hollow and solid fiber structures. Polypropylene hollow fibers were melt-spun with a four-segmented arc (4C) die under the wide ranges of spinning conditions (0.25–0.83 g/min of polymer mass throughput per a fiber, 500–2000 m/min of spinning speed, and 5%–100% quench rate). Fiber structure was explored through thermal, geometric, and tensile properties. Fiber hollowness depends on all spinning parameters studied (mass throughput, spinning speed, and quench rate). Increasing the quench rate resulted in the fiber solidifications closer to the spinneret. This leads to higher hollowness but also affected fiber tensile properties. When hollow and solid fibers were compared at constant quench, the hollow fiber solidified faster than solid fiber. The crystallinity of the fibers remained similar, but the tensile modulus was higher for hollow fiber than for solid fiber.

scholarly journals Effect of Cooling Rate on the Microstructure Evolution and Mechanical Properties of Iron-Rich Al–Si Alloy

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 411
Author(s):  
Xiao Shen ◽  
Shuiqing Liu ◽  
Xin Wang ◽  
Chunxiang Cui ◽  
Pan Gong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Cooling Rate ◽  
Melt Spinning ◽  
Silicon Phase ◽  
Rich Phase ◽  
The Matrix ◽  
Granular Morphology ◽  
Morphology Changes ◽  
Al Matrix

The mechanical properties of iron-rich Al–Si alloy is limited by the existence of plenty of the iron-rich phase (β-Al5FeSi), whose unfavorable morphology not only splits the matrix but also causes both stress concentration and interface mismatch with the Al matrix. The effect of the cooling rate on the tensile properties of Fe-rich Al–Si alloy was studied by the melt spinning method at different rotating speeds. At the traditional casting cooling rate of ~10 K/s, the size of the needle-like β-Al5FeSi phase is about 80 μm. In contrast, the size of the β-Al5FeSi phase is reduced to 500 nm and the morphology changes to a granular morphology with the high cooling rate of ~104 K/s. With the increase of the cooling rate, the morphology of the β-Al5FeSi phase is optimized, meanwhile the tensile properties of Fe-rich Al–Si alloy are greatly improved. The improved tensile properties of the Fe-rich Al-Si alloy is attributed to the combination of Fe-rich reinforced particles and the granular silicon phase provided by the high cooling rate of the melt spinning method.

EM of rapidly solidified permanent magnets

1992 ◽  
Vol 50 (1) ◽  
pp. 198-199
Author(s):  
Raja K. Mishra
Keyword(s):  
Melt Spinning ◽  
Permanent Magnets ◽  
Dark Field Image ◽  
Dark Field ◽  
Maximum Energy ◽  
Quench Rate ◽  
Maximum Energy Product ◽  
Energy Product ◽  
Annular Dark Field ◽  
Rapidly Solidified

The discovery of a new class of permanent magnets based on Nd2Fe14B phase in the last decade has led to intense research and development efforts aimed at commercial exploitation of the new alloy. The material can be prepared either by rapid solidification or by powder metallurgy techniques and the resulting microstructures are very different. This paper details the microstructure of Nd-Fe-B magnets produced by melt-spinning.In melt spinning, quench rate can be varied easily by changing the rate of rotation of the quench wheel. There is an optimum quench rate when the material shows maximum magnetic hardening. For faster or slower quench rates, both coercivity and maximum energy product of the material fall off. These results can be directly related to the changes in the microstructure of the melt-spun ribbon as a function of quench rate. Figure 1 shows the microstructure of (a) an overquenched and (b) an optimally quenched ribbon. In Fig. 1(a), the material is nearly amorphous, with small nuclei of Nd2Fe14B grains visible and in Fig. 1(b) the microstructure consists of equiaxed Nd2Fe14B grains surrounded by a thin noncrystalline Nd-rich phase. Fig. 1(c) shows an annular dark field image of the intergranular phase. Nd enrichment in this phase is shown in the EDX spectra in Fig. 2.

In situ TEM observations of melting in nanosized eutectic Pb-Cd inclusions embedded in Al

1996 ◽  
Vol 54 ◽  
pp. 986-987
Author(s):  
S. Hagège ◽  
U. Dahmen ◽  
E. Johnson ◽  
A. Johansen ◽  
V.S. Tuboltsev
Keyword(s):  
Electron Microscope ◽  
Melt Spinning ◽  
Ternary Alloys ◽  
Solid Matrix ◽  
Eutectic System ◽  
In Situ Tem ◽  
In Situ Observation ◽  
Orientation Relationships ◽  
Transmission Electron

Small particles of a low-melting phase embedded in a solid matrix with a higher melting point offer the possibility of studying the mechanisms of melting and solidification directly by in-situ observation in a transmission electron microscope. Previous studies of Pb, Cd and other low-melting inclusions embedded in an Al matrix have shown well-defined orientation relationships, strongly faceted shapes, and an unusual size-dependent superheating before melting.[e.g. 1,2].In the present study we have examined the shapes and thermal behavior of eutectic Pb-Cd inclusions in Al. Pb and Cd form a simple eutectic system with each other, but both elements are insoluble in solid Al. Ternary alloys of Al (Pb,Cd) were prepared from high purity elements by melt spinning or by sequential ion implantation of the two alloying additions to achieve a total alloying addition of up to lat%. TEM observations were made using a heating stage in a 200kV electron microscope equipped with a video system for recording dynamic behavior.

Electron spectroscopic imaging (ESI) on multiphase polymer materials

1989 ◽  
Vol 47 ◽  
pp. 348-349
Author(s):  
H.-J. Cantow ◽  
M. Kunz ◽  
M. Möller
Keyword(s):  
Energy Loss ◽  
Melt Spinning ◽  
Chromatic Aberration ◽  
Element Distribution ◽  
Polymer Materials ◽  
Specific Energy Loss ◽  
Transmission Electron ◽  
Multicomponent Polymer ◽  
Diffraction Patterns ◽  
Image Planes

In transmission electron microscopy the natural contrast of polymers is very low. Thus the contrast has to be enhanced by staining with heavy metals. The resolution is limited by the size of the staining particles and by the fact that electrons with different energy are focused in different image planes due to the chromatic aberration of the magnetic lenses. The integration of an electron energy loss spectrometer into the optical coloumn of a transmission electron microscope offers the possibility to use monoenergetic electrons and to select electrons with a certain energy for imaging. Thus contrast and resolution are enhanced. By imaging only electrons with an element specific energy loss the element distribution in the sample can be obtained. In addition, elastic bright field images and diffraction patterns yield excellent resolution. Some applications of the method on multicomponent polymer materials are discussed.Bulk polymer samples were prepared by ultramicrotoming at room temperature or well below the glass transition temperature. Very thin films for the direct observation of the structure in semicrystalline polymers were obtained by melt-spinning. Specimens were examined with a ZEISS CEM 902 operated at 80 kV.

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