The paper is devoted to the study of microstructural and magnetic properties of the Fe-based amorphous ribbons after interference pulsed laser heating. The ternary amorphous alloy FeSiB, as well as the multi-component alloys FeCuSiB and FeCuNbSiB, was subjected to laser pulses to induce crystallization in many microislands simultaneously. Structure and properties changes occurred in laser-heated dots. Detailed TEM analysis from a single dot shows the presence of FeSi(α) nanocrystals in the amorphous matrix. The FeSiB alloy is characterized after conventional crystallization by a dendritic structure; however, the alloys with copper as well copper and niobium additions are characterized by the formation of equiaxed crystals in the amorphous matrix. Amorphous alloys before and after the laser heating are soft magnetic; however, conventional crystallization leads to a deterioration of the soft magnetic properties of the material.

The surface texture of dental restorations has a major influence on plaque accumulation and aesthetical appearance. The study aimed to evaluate the surface roughness of composite resins depending on the varying polishing sequences and applied forces. A total of 60 samples from two composite resins (Boston and Charisma) were polymerized using a lamp with 1200 mW/cm2 intensity and covering celluloid strip. The polishing sequence consisted of 12.6 mm OptiDisc (Kerr) – with increased disc per each subsequent step. Half of the samples were polished at 1N force, with the other half at 2N. The surface roughness examination was performed using a WYKO NT930 (Veeco) optical profilometer. The selected roughness parameters were compared by ANOVA with the significance level α = 0.05. The more complex polishing sequence affected on the composite smoothness. Higher roughness was identified in Charisma samples as compared to Boston. The specimens polished with 2N force contained a slightly rougher surface than those polished with 1N. However, these differences were not statistically significant. Despite the satisfactory visual effect obtained by polishing the composite samples, the profilometric examination revealed the roughness. Finishing is crucial for providing a smooth composite surface, allowing it to function properly in the oral environment.

Abstract-The main problem connected with crystallization of amorphous magnetic materials from the FeSiB(X) group is the increase of their fragility with an increasing content of the crystalline phase. To overcome this defect the possibilities offered by the interference, pulse laser heating of FeSiB ribbons were utilized. A simple interference prismatic system at the output of Nd:YAG laser (8-10ns, 2J, 1064nm) was used. The investigations included the influence of laser radiation energy density, number of laser pulses and their periodical spatial surface arrangement on the crystallization process.

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The influence of Q-switched pulsed Nd:YAG laser interference heating, using 120 mJ of pulse energy and a variable number of consecutive pulses, on the microstructure and magnetic properties of amorphous Fe80Si11B9 alloy was examined. Microstructural analysis, using light, scanning and transmission electron microscopy, was complemented by results of Mössbauer spectroscopy and measurement of magnetic properties (vibrating sample magnetometer). Periodically distributed crystallized micro-areas, ∼10 μm in diameter, in an amorphous matrix were produced by the treatments. Magnetization measurements showed that the as-cast ribbon and laser light irradiated samples are magnetically soft materials. The results lead to the conclusion that the dots corresponding to the laser modified regions exhibit a perpendicular magnetic anisotropy.