Microstructure and Microhardness of Ti6Al4V Alloy Treated by GTAW SiC Alloying

In this work, the change of the structure and microhardness of Ti6Al4V titanium alloy after remelting and remelting with SiC alloing by electric arc welding (GTAW method) was studied. The current intensity equal 100 A and fixed scan speed rate equal 0,2 m/min has been used to remelting surface of the alloy. Change of structure were investigated by optical and scanning electron microscopy. Microhardness test showed, that the remelting of the surface does not change the hardness of the alloy. Treated by GTAW SiC alloying leads to the formation of hard (570 HV0, 1) surface layer with a thickness of 2 mm. The resulting surface layer is characterized by diverse morphology alloyed zone. The fracture of alloy after conventional heat treatment, similarly to fracture after remelting with GTAW is characterized by extremely fine dimples of plastic deformation. In the alloyed specimens the intergranular and crystalline fracture was identified

Reprogrammability and Scalability of Magnonic Fibonacci Quasicrystals

Magnonic quasicrystals can be used to manipulate spin waves, offering possibilities beyond those of periodic magnonic crystals. The authors investigate one-dimensional magnonic Fibonacci quasicrystals and demonstrate the existence of collective spin waves over a broad range of wave vectors. The spin-wave spectra here are tunable by changing magnetic field amplitude (for continuous band-structure adjustment), magnetization configuration (for reprogrammability), or the dimensions of the elements (for scalability). Beyond being fundamentally interesting, these properties show that magnonic quasicrystals are promising for tomorrow's spintronic, microwave, and magnonic technologies