Advanced Ways and Experimental Methods in Self-Propagating High-Temperature Synthesis (SHS) of Inorganic Materials

Abstract

New experimental methods for investigations of phase formation during SHS have been established. First experiments using penetrating synchrotron radiation and energy dispersive detectors for different classes of complex inorganic materials were carried out at ESRF (Grenoble, France) and Daresbury (UK). A new and very sensitive thermal imaging method (Thermal Imaging Technique (TIT)) based on continuous registration of the whole combustion process by using highly sensitive IR-camera and software developed by MIKRON Instruments Co. (USA) was used for precise registration of the combustion parameters. SHS was performed on different types of pure and doped complex inorganic materials in pellet and powder form in a range of dc magnetic fields up to 20 T and in electrical field strengths up to ±220 kV/m. The dc magnetic field was applied during the reaction, supplied either by a permanent magnet (transverse, up to 1.1 T) or by an electromagnet (longitudinal, up to 20 T). The dc electrical field was applied along the direction of the combustion wave front propagation. The combined processes of SHS and SLS (Selective Laser Sintering) of 3D articles for different powdered compositions were optimized with laser irradiation power.

Investigation of microwave absorption properties of multi-layer nanostructure BaFe12O19/epoxy composites

“…According to the references [16], the reactions and temperatures to obtain BaFe 12 O 19 are in the following reactions:…”

Consolidation phenomena in laser and powder-bed based layered manufacturing

“…Other (potential) examples of "Selective Laser Reactive Sintering" were investigated at the University of Texas at Austin [11]. Some investigators tried to apply self-propagating high-temperature synthesis (SHS) in which a low laser power induces a selfpropagating exothermal reaction capable of self-heating and consolidating the powder in a controllable way [107,177,182]. This allows reducing the laser power significantly.…”

EMF measurements across the front of combustion wave during layer by layer surface laser sintering of exothermal powder compositions

“…5). By lowering the exothermicity of SHS reaction is should be possible to enable SLS to initiate I -44 • .1 p -the reaction only at the laser spot [1][2][3]. Therefore it is important to be convinced as to formation of the new chemical compounds at the measured temperatures and estimate the degree of chemical transformation during SLS+SHS.…”

“…This method allows fabrication of three-dimensional parts by using a spatially selective laser influence (LI) on the surface of powder compositions [1][2][3] . The direct formation of functional materials and tools of the required shape is a distinctive feature of SLS.…”