scholarly journals Surface Micromorphology and Structure of Stainless and Maraging Steel Obtained via Selective Laser Melting: A Mössbauer Spectroscopy Study

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1028
Author(s):  
Fredericus Linderhof ◽  
Miroslav Mashlan ◽  
Hana Doláková ◽  
Tomáš Ingr ◽  
Tatiana Ivanova
Keyword(s):  
Mössbauer Spectroscopy ◽  
Phase Composition ◽  
Selective Laser Melting ◽  
Mossbauer Spectroscopy ◽  
Three Dimensional ◽  
Surface Phase ◽  
Laser Melting ◽  
X Ray ◽  
Manufacturing Method ◽  
Mößbauer Spectroscopy

Selective laser melting (SLM) as an additive manufacturing method makes it possible to quickly produce complexly shaped three-dimensional (3D) metal specimens from a powder. This work describes how SLM affects the surface phase composition of a 3D printed specimen, as analyzed with conversion electron Mössbauer spectroscopy (CEMS), conversion X-ray Mössbauer spectroscopy (CXMS) and X-ray diffraction (XRD). Both stainless 1.4404 (CL20ES) steel and maraging 1.2709 (CL50WS) steel have been investigated. A transformation of the phase composition from the ferritic phase into an austenitic one was proven by comparing the initial CL50WS powder and the final specimen using CXMS. This transformation takes place during the SLM process. No transformation was identified in stainless steel. The differences identified via CEMS between the surface phase composition of the final non-annealed specimens and the surface of the final annealed specimens demonstrated the oxidation of the surface layer. The oxidation occurs during the annealing of the sample in surface layers less than 1 μm thick. The quality of the surface was examined using scanning electron microscopy (SEM), which presented imperfections on the face of the final specimen. Granules of the initial powder bonded to the surface of the specimen and both irregular and spherical pores were observed.

The Comparative Study of Phase Composition of Steels Using X-Ray Diffraction and Mössbauer Spectroscopy Methods

2013 ◽  
Vol 203-204 ◽  
pp. 150-155
Author(s):  
Piotr Pawluk ◽  
Emilia Skołek ◽  
Michał Kopcewicz ◽  
Wiesław Świątnicki
Keyword(s):  
Mössbauer Spectroscopy ◽  
Phase Composition ◽  
Retained Austenite ◽  
Mossbauer Spectroscopy ◽  
Rietveld Method ◽  
Bainitic Ferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Diffraction Patterns

In this paper phase composition of several steels was investigated by X-ray diffraction and conversion electron Mössbauer spectroscopy (CEMS) methods. Different heat treatments were performed on steel samples in order to obtain various phase compositions (containing bainitic ferrite, martensite and retained austenite). The diffraction patterns were analysed using the Rietveld method. Mössbauer spectra were fitted and studied for existent phases. A comparison between results obtained by each method was performed. Both methods revealed some supersaturation of carbon in the retained austenite and in the bainitic ferrite phases, various after different treatments. The quantitative phase composition measured by X-ray diffraction results differ significantly from the Mössbauer spectroscopy results. The possible reasons of the observed differences were discussed.

The stannides RE3Au6Sn5 (RE = La, Ce, Pr, Nd, Sm) – synthesis, structure, magnetic properties and 119Sn Mössbauer spectroscopy

2015 ◽  
Vol 70 (6) ◽  
pp. 425-434 ◽  
Author(s):  
Thomas Fickenscher ◽  
Ute Ch. Rodewald ◽  
Oliver Niehaus ◽  
Birgit Gerke ◽  
Sandra Haverkamp ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Rare Earth ◽  
Mossbauer Spectroscopy ◽  
Three Dimensional ◽  
Significant Degree ◽  
Tin Compounds ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Antiferromagnetic Ordering ◽  
Arc Melting

AbstractThe Ce3Pd6Sb5-type rare earth stannides RE3Au6Sn5 (RE= La, Ce, Pr, Nd, Sm) were synthesized by arc-melting of the elements and subsequent annealing in open tantalum crucibles within sealed evacuated silica ampoules. The polycrystalline samples were studied by powder X-ray diffraction. The structures of three crystals were refined from single crystal X-ray diffractometer data: Pmmn, a= 1360.3(9), b= 455.9(2), c= 1023.6(4) pm, wR2 = 0.0275, 1069 F2 values, 48 variables for Ce3Au6Sn5, a= 1352.4(4), b= 455.1(1), c= 1023.7(3) pm, wR2 = 0.0367, 1160 F2 values, 48 variables for Nd3Au6Sn5, and a= 1339.8(2), b= 452.80(7), c= 1012.4(2) pm, wR2 = 0.1204, 1040 F2 values, 49 variables for Sm3Au5.59(2)Sn5.41(2). One of the gold sites of the samarium compound shows a significant degree of Au/Sn mixing. The RE3Au6Sn5 structures are composed of three-dimensional [Au6Sn5] polyanionic networks with the two crystallographically independent rare earth atoms in larger cages, i.e., RE1@Au10Sn6 and RE2@Au8Sn8. The [Au6Sn5] network is stabilized by Au–Sn (266–320 pm), Au–Au (284–301 pm) as well as Sn–Sn (320 pm; distances given for the cerium compound) interactions. Temperature-dependent magnetic susceptibility measurements reveal an antiferromagnetic ordering only for Sm3Au6Sn5, while the other compounds exhibit Curie–Weiss paramagnetism. 119Sn Mössbauer spectroscopy shows resonances in the typical range for intermetallic tin compounds where tin takes part in the polyanionic network [isomer shifts between 1.73(1) and 2.28(1) mm·s−1]. With the help of theoretical electric field gradient calculations using the WIEN2k code it was possible to resolve the spectroscopic contributions of all three crystallographically independent atomic tin sites in the 119Sn spectra of RE3Au6Sn5 (RE= La, Ce, Pr, Nd, Sm).

Nature and mechanism of ilmenite alteration: a Mössbauer and X-ray diffraction study of oxidized ilmenite from the Beja-Acebuches Ophiolite Complex (SE Portugal)

2002 ◽  
Vol 66 (3) ◽  
pp. 421-430 ◽  
Author(s):  
J. C. Waerenborgh ◽  
J. Figueiras ◽  
A. Mateus ◽  
M. Gonçalves
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Ophiolite Complex ◽  
Cation Site ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Ilmenite Structure ◽  
Optical Evidence ◽  
Excess Fe

AbstractIlmenites from the least-altered rocks of the Beja-Acebuches Ophiolite Complex (SE Portugal), with low Ti values and excess Fe, despite rare optical evidence of hematite exsolution, were studied by 57Fe Mössbauer spectroscopy and X-ray diffraction. According to single-crystal XRD the sequence of alternate layers characteristic of the ideal ilmenite structure is preserved, the excess Fe being accommodated in the Ti layers. No superparamagnetic oxides were detected by 57Fe Mössbauer spectroscopy. The typical spectra of bulk αFe2O3 and of Fe3+-containing ilmenite, in the paramagnetic state above 49 K and magnetically ordered at 6 K, are observed. The average degree of oxidation of the ilmenites, estimated from the chemical analysis assuming ideally stoichiometric full cation site occupancies, is also confirmed by 57Fe Mössbauer data. Since our crystal chemistry study gave no evidence of crypto-exsolution textures within the ilmenite with the observed compositions, fast cooling from magmatic temperatures and decomposition of ilmenite in supergene conditions is suggested.

A Study of Aluminum-Substituted Iron Dextran Complexes by Mössbauer Spectroscopy and X-ray Diffraction

2001 ◽  
Vol 13 (1) ◽  
pp. 136-140 ◽  
Author(s):  
Tianrong Cheng ◽  
Robert Bereman ◽  
Eddy De Grave ◽  
Larry H. Bowen
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Iron Dextran ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mößbauer Spectroscopy
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