scholarly journals In Situ WAXD and SAXS during Tensile Deformation Of Moulded and Sintered Polyamide 12

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1001 ◽  
Author(s):  
Fabio Paolucci ◽  
Leon Govaert ◽  
Gerrit Peters
Keyword(s):  
Mechanical Response ◽  
Mechanical Performance ◽  
Tensile Deformation ◽  
Constant Strain Rate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polyamide 12 ◽  
X Ray Scattering ◽  
The Difference

To provide knowledge to improve the mechanical performance of Polyamide 12 (PA12) sintered products, we have studied experimentally the mechanical response and structure development under constant strain rate of compression moulded and laser sintered PA12 by means of in situ small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) experiments. It is found that at low temperatures, i.e., below the glass transition temperature, the brittle failure of laser sintered samples is determined by the fast formation of voids that originate at the beginning of the macroscopic plastic deformation. This effect appears to be faster at temperatures below room temperature and it is less effective at higher temperatures. When tested at 120 ∘ C, sintered PA12 shows a better mechanical response in terms of yield stress and a comparable strain at break with respect to moulded PA12. This can be explained by considering that sintered samples have slightly thicker crystals that can sustain higher stress at high temperature. However, this also leads to the formation of a larger number of voids at low testing temperatures. This work does not attempt to quantify the micromechanics behind crystals deformation and disruption, but it provides a deeper insight in the difference between the mechanical response of moulded and sintered PA12.

In Situ Synchrotron SAXS/WAXD Study during Uniaxial Drawing of Poly (L-Lactic Acid)

2014 ◽  
Vol 1048 ◽  
pp. 404-409
Author(s):  
Takahiko Kawai ◽  
Shin-ichi Kuroda
Keyword(s):  
Lactic Acid ◽  
Mechanical Response ◽  
Early Stage ◽  
Amorphous Film ◽  
X Ray Diffraction ◽  
X Ray ◽  
Saxs Measurement ◽  
X Ray Scattering ◽  
Shish Structure

The structure development of poly (L-lactic acid)(PLLA) during the uniaxial drawing was investigated by means of in-situ simultaneous wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) measurements. When the quenched amorphous film of PLLA was drawn at 77.2 oC, which was well above the glass transition temperature of PLLA, two different crystal structures were formed depending on the strain. The mesophase, which has 103 helix with large amount of packing disorder, was formed at the early stage of drawing, followed by the crystal transformation into α’ form (ε ≥ 1.5). SAXS measurement showed that the kebab formation begins at the stage later than that of meso-α’ transition. It strongly suggests that the transition takes place inside the shish structure. The development of kebab leads to the enhancement of mechanical response, which is found to be the origin of the strain hardening of PLLA.

scholarly journals In Situ Synchrotron X-ray Study of the Mechanical Properties of Pure Mg Produced by Powder Metallurgy

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1198
Author(s):  
Li Li ◽  
Leyun Wang ◽  
Jie Wang ◽  
Huan Zhang ◽  
Qingchun Zhu ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Tensile Deformation ◽  
Line Broadening ◽  
X Ray ◽  
X Ray Scattering ◽  
Type Dislocation ◽  
Diffraction Patterns ◽  
Saxs Analysis ◽  
Ray Scattering

In this study, in situ synchrotron X-ray experiments with wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) detectors were performed on two pure magnesium materials produced by powder metallurgy. According to SAXS analysis, each of the two materials has a porosity of less than 0.5%. Line broadening analysis was performed on diffraction patterns collected by WAXS to analyze the dislocation evolution during material deformation. In both materials, <a>-type dislocation activities dominate the tensile deformation. The influence of grain size and texture on the different tensile behaviors of these two materials is also discussed.

In situ coupling of atomic force microscopy and sub-micrometer focused X-ray techniques

2014 ◽  
Vol 1712 ◽  
Author(s):  
Thomas W. Cornelius ◽  
Zhe Ren ◽  
Francesca Mastropietro ◽  
Simon Langlais ◽  
Anton Davydok ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Elemental Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Nanowires ◽  
Force Microscopy ◽  
Indentation Tests ◽  
Scanning Force ◽  
Diffraction Patterns

ABSTRACTA scanning force microscope for in situ nanofocused X-ray studies (SFINX) has been developed which can be installed on diffractometers at synchrotron beamlines allowing for the combination with various techniques such as coherent X-ray diffraction and fluorescence. The capabilities of this device are demonstrated on Cu nanowires and on Au islands grown on sapphire (0001). The sample topography, crystallinity, and elemental distribution of the same area are investigated by recording simultaneously an AFM image, a scanning X-ray diffraction map, and a fluorescence map. Additionally, the mechanical response of Au islands is studied by in situ indentation tests employing the AFM-tip and recording 2D X-ray diffraction patterns during mechanical loading.

In Situ High Temperature X-Ray Diffraction Studies of Modified Poly(Ethylene Terephthalate)

1992 ◽  
Vol 36 ◽  
pp. 379-386
Author(s):  
T. Blanton ◽  
R. Seyler
Keyword(s):  
High Temperature ◽  
Ethylene Terephthalate ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Pet Crystallization

The effect of dimethyl-5-sodiosulfoisophthalate, SIP, on poly(ethylene terephthalate), PET, crystallization has been studied using in situ high-temperature x-ray diffraction, HTXRD. At low levels of SIP modification, PET-like crystallinity was observed. At high SIP levels, clustering of polyester ionomers was observed and crystallization was significantly suppressed. The HTXRD data along with differential scanning calorimetry, DSC, and small angle x-ray scattering, SAXS, indicate that the change from bulk crystallization to bulk ionomer formation occurred when 8-12 mol% of the diester linkages contained SIP.

In-Situ X-ray Diffraction Study of Lithium Intercalation in Nanostructured Anatase Titanium dioxide

1998 ◽  
Vol 536 ◽  
Author(s):  
R. Van de Krol ◽  
E. A. Meulenkamp ◽  
A. Goossens ◽  
J. Schoonman
Keyword(s):  
Phase Transformation ◽  
Maximum Amount ◽  
Lithium Intercalation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After ◽  
The Difference ◽  
Two Phases ◽  
Reversible Phase

AbstractElectrochemical lithium intercalation in nanostructured anatase TiO2 is investigated with in-situ X-ray diffraction. A complete and reversible phase transformation from tetragonal anatase TiO2 to orthorhombic anatase Li0.5TiO2 is observed. The difference of the XRD spectra before and after insertion can be fitted with the lattice parameters of the two phases as fit parameters. The maximum amount of lithium that can be dissolved in anatase TiO2 before the phase transformation occurs is found to be very small.

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