Dr. Malgorzata Grazyna Makowska
Photons for Engineering and Manufacturing Group
5232 Villigen PSI
Malgorzata Makowska graduated from Gdansk University of Technology in Applied Physics. She finished her PhD at the Department of Energy Conversion and Storage of Technical University of Denmark in collaboration with European Spallation Source (ESS ERIC) in 2015. In years 2016-2018 she worked as an instrument scientist at the fast neutron imaging beamline NECTAR at FRM II, Heinz Maier-Leibnitz Zentrum (MLZ) (Garching, Germany). Since 2018 she is a postdoc in the group of Prof. Helena Van Swygenhoven, Photons for Engineering and Manufacturing (PEM).
Malgorzata Makowska is responsible for the PSI contribution in SFA Advanced Manufacturing projects FUORCLAM and CeramicX.0.
Cracks, porosity and microstructure of Ti modified polymer-derived SiOC revealed by absorption-, XRD- and XRF-contrast 2D and 3D imaging, M. Makowska, P.V.W. Sasikumar, L. Hagelüken, D.F. Sanchez, N. Casati, F. Marone, G. Blugan, J. Brugger, H. Van Swygenhoven, Acta Mater. (2020).
Morphology, phase composition, cracks and porosity are investigated in monolithic Ti modified SiOC polymer-derived ceramics pyrolyzed at 1000°C and 1400°C using synchrotron X-ray full field absorption-contrast tomographic microscopy and scanning XRF- and XRD-contrast microscopy. Samples pyrolyzed at 1000°C show a crack-free structure, but pyrolysis at 1400°C results in formation of cracks and at higher Ti content also shows porosity. Tomography revealed the formation of a layered morphology that varies in terms of crystallographic structure and/or Ti stoichiometric concentration. The microstructural observations and electrical conductivity are discussed in terms of pyrolysis temperature and Ti content.
Selective laser melting of thermal pre-treated METAL oxide doped aluminum oxide granules, S. Pfeiffer, M. Makowska, Kevin Florio, D.F. Sanchez, F. Marone, X. Zhang, C.G. Aneziris, H. Van Swygenhoven, K. Wegener, T. Graule, Open Ceram.
The influence of powder bed density on the final density and microstructure of aluminum oxide parts manufactured by direct selective laser melting has been studied. Iron oxide and manganese oxide nanoparticles were used to improve laser absorption by over eighty percent. To achieve such values, flowable doped alumina granules were prepared by spray drying. Thermal treatment of the granules at 1600 °C and consecutive mixing with coarse alumina allowed improvement of the tapped powder densities, reaching a maximum value of 56.4% of the theoretical density. This led to laser processed parts with densities up to 98.6% measured by tomographic microscopy. Measurements with an integrating sphere and an UV-VIS-NIR spectrophotometer employing Kubelka-Munk theory show the decrease of absorptance caused by thermal pre-treatment. 3D mapping by X-ray μ-beam fluorescence contrast tomography and high resolution synchrotron powder diffraction provide information about the variation of dopant distribution and composition within the granules.
Additive micromanufacturing of crack-free PDCs by two-photon polymerization of a single, low-shrinkage preceramic resin, G. Konstantinou, E. Kakkava, L. Hagelüken, P.V. Warriam Sasikumar, J. Wang, M.G. Makowska, G. Blugan, N. Nianias, F. Marone, H. Van Swygenhoven, J. Brugger, D. Psaltis, C. Moser, Addit. Manuf. (2020) 101343.
Additive manufacturing (AM) methods are being integrated in ceramics fabrication either as the main manufacturing tool or for auxiliary purposes. By using polymers, powders and preceramic formulated materials, AM techniques are pushing towards higher resolution, lower shrinkage and shorter building time. Herein, we present the fabrication of ceramic microstructures (<200×200×200 μm3) with sub-micrometer resolution based on two-photon polymerization (TPP). 3D structuring of a preceramic resin by photopolymerization produces a so-called green body. The final ceramic part is obtained after pyrolysis of the green body. The high-resolution 3D shaped structures that we demonstrated could be employed as tools or components for microdevices. We report a lower linear shrinkage of 30% of TPP green bodies from a polysiloxane precursor with low porosity, no cracks and no significant shape distortion after pyrolysis, which implies the potential for highly controllable manufacturing of micro-ceramic parts based on commercially available chemical compounds. The protocol for preparing, fabricating and developing the resin is detailed.
Pre-processing of hematite-doped alumina granules for Selective Laser Melting, M. Makowska, S. Pfeiffer, N. Casati, K. Florio, M. Vetterli, K. Wegener, T. Graule, H. Van Swygenhoven, Ceram. Int. 45 (2019) 17014–17022.
Structure and composition evolution of α-Fe2O3 doped alumina granules during calcination is investigated by means of synchrotron X-ray powder diffraction. The α-Fe2O3 nanoparticles are added to increase the absorption of laser light, however, they also play a significant role in transition kinetics of alumina. It is shown that calcination in air leads to implementation of Fe3+ ions in corundum structure, while calcination in reducing atmosphere leads to creation of metallic iron. Moreover, it is demonstrated that for alumina granules consisting of a mixture of micron-size α-alumina, submicron α-alumina and nano-size γ−/δ-alumina, it is possible to obtain a system composed of two corundum-type structures with different Fe doping levels and the ratio of these two phases can be controlled by calcination temperature.
An Innovative Selective Laser Melting Process for Hematite-Doped Aluminum Oxide, K. Florio, S. Pfeiffer, M. Makowska, N. Casati, F. Verga, T. Graule, H. Van Swygenhoven, K. Wegener, Adv. Eng. Mater. (2019) 1801352.
Selective Laser Melting (SLM) technology is successfully applied to manufacture aluminum oxide parts. The obtained samples are presented and characterized in terms of density, mechanical properties, and structure. The starting material is a powder composed of aluminum oxide granules doped with a small quantity of iron oxide (hematite) as an absorption additive. A green short-pulsed nanosecond (ns) laser is used in the experimental in-house designed and built SLM machine. The absorption, reflectance, and transmittance of the starting powder for a laser with wavelength of 532 nm are evaluated using an integrating sphere and it is found that absorption of 68% is sufficient for the established process. Various laser and scanning parameters are studied and a process window is found. Densities above 90% are achieved in the one step process. Bi-axial flexural strength of 25 MPa in average is recorded in the ball on 3 balls test. Finally, powder diffraction measured in a synchrotron beamline shows the presence of less than 0.6% of hercynite after laser processing.