Comparative analysis of microstructure,mechanical,and corrosion properties of biodegradable Mg-3Y alloy prepared by selective laser melting and spark plasma sintering

This work explored possibilities of biodegradable magnesium alloy Mg-3Y preparation by two modern powder metallurgy techniques–spark plasma sintering(SPS)and selective laser melting(SLM).The powder material was consolidated by both methods utilising optimised parameters,which led to very low porosity(∼0.3%)in the SLM material and unmeasurably low porosity in the SPS material.The main aim of the study was the thorough microstructure characterisation and interrelation between the microstructure and the functional properties,such as mechanical strength,deformability,and corrosion resistance.Both materials showed comparable strength of∼110 MPa in tension and compression and relatively good deformability of∼9%and∼21%for the SLM and SPS materials,respectively.The corrosion resistance of the SPS material in 0.1 M NaCl solution was superior to the SLM one and comparable to the conventional extruded material.The digital image correlation during loading and the cross-section analysis of the corrosion layers revealed that the residual porosity and large strained grains have the dominant negative effect on the functional properties of the SLM material.On the other hand,one of the primary outcomes of this study is that the SPS consolidation method is very effective in the preparation of the W3 biodegradable alloy,resulting in material with convenient mechanical and degradation properties that might find practical applications.

Laser produced electromagnetic pulses: generation, detection and mitigation

This paper provides an up-to-date review of the problems related to the generation,detection and mitigation of strong electromagnetic pulses created in the interaction of high-power,high-energy laser pulses with different types of solid targets.It includes new experimental data obtained independently at several international laboratories.The mechanisms of electromagnetic field generation are analyzed and considered as a function of the intensity and the spectral range of emissions they produce.The major emphasis is put on the GHz frequency domain,which is the most damaging for electronics and may have important applications.The physics of electromagnetic emissions in other spectral domains,in particular THz and MHz,is also discussed.The theoretical models and numerical simulations are compared with the results of experimental measurements,with special attention to the methodology of measurements and complementary diagnostics.Understanding the underlying physical processes is the basis for developing techniques to mitigate the electromagnetic threat and to harness electromagnetic emissions,which may have promising applications.