Search results

Sort By:

Limit search:

In Situ Investigation of Microstructure Evolution during Solidification of Mg10CaxGd (x=5, 10, 20) Alloys

100%

Mendis C., Tolnai D., Stark A., Schell N., Kainer K., Hort N.

Acta Physica Polonica A

2015

vol. 128

issue 4

606-610

Mg-Ca-Gd based alloys are investigated as a potential alloy for degradable biomaterials with some promising results. In this investigation the Mg10CaxGd (x=5, 10, 20) were investigated with synchrotron radiation X-ray diffraction during solidification to follow the phase evolution at two different cooling rates at 5 and 50 K min^{-1}. All three alloys show formation of α -Mg followed by Mg₂Ca phase, while only Mg10Ca20Gd alloy contained Mg₅Gd phase during solidification. During cooling α -Mg was first observed between 628 and 632°C at a cooling rate of 5 K min^{-1} while this decreased to 620-628°C with the increase in cooling rate to 50 K min^{-1}. The change in cooling rate from 5 to 50 K min^{-1} did not change the types of intermetallic phases observed but resulted in suppressing temperatures at which the intermetallic phases were first detected.

Monitoring of Heat Treatment Processes by High Energy Synchrotron Radiation

84%

Klemradt U., Rieger T., Herrmann K., Carmele D., Meyer S., Lippmann T., Stark A., Bleck W.

Acta Physica Polonica A

2012

vol. 121

issue 1

39-43

Advanced engineering materials are frequently based on multiphase microstructures, where the decisive step is the heat treatment adjusting the desired microstructure. A typical example are transformation-induced plasticity assisted steels, where the steel grades depend on the phase composition and the deformation-induced transformation of retained austenite into martensite. Usually methods for microstructural characterization are only applied after completion of the heat treatment process and comprise typically microscopy and X-ray analysis with laboratory tubes. Both methods can suffer from artefacts and probe a relatively small surface or volume, respectively. However, in the last decade synchrotron facilities have become available that offer very hard X-rays, which open up new possibilities for the observation of heat treatment processes owing to the unique combination of extremely high intensities with large penetration depths (mm scale). Sophisticated sample environments allow for complex in situ experiments, currently with a time resolution on the order of seconds. Only recently a commercial dilatometer of type Bähr Dil805AD has become available at the HARWI-2 beamline at the HASYLAB. This experimental setup was used for the in situ investigation of the quenching and partitioning process in transformation-induced plasticity steels. The experiments were performed in transmission at a wavelength of 0.0124 nm. The Debye-Scherrer rings were observed arising from statistical grain distributions characteristic for each microstructure. The time-resolved measurements allow conclusions about the phases present in the sample, their lattice parameters, texture and grain size.

Refine search results

2 Acta Physica Polonica A

1 2015

1 2012

2 Stark A.

1 Bleck W.

1 Carmele D.

1 Herrmann K.

1 Hort N.

1 Kainer K.

1 Klemradt U.

1 Lippmann T.

1 Mendis C.

1 Meyer S.

1 Rieger T.

1 Schell N.

1 Tolnai D.

Search results

In Situ Investigation of Microstructure Evolution during Solidification of Mg10CaxGd (x=5, 10, 20) Alloys

Monitoring of Heat Treatment Processes by High Energy Synchrotron Radiation