Study on nanocrystalline grain size and quantitative change in Fe–Cu–Mo–Si–B soft magnetic alloy

In this paper, we studied the grain size and volume fraction change of [Formula: see text]-Fe(Si) nanocrystalline phase as a function of Cu, Mo and Si content in Fe[Formula: see text]Cu[Formula: see text]Mo3Si[Formula: see text]B9, Fe[Formula: see text]Cu1Mo[Formula: see text]Si[Formula: see text]B9, Fe[Formula: see text]Cu1Mo3Si[Formula: see text]B[Formula: see text], and also the annealing temperature and time in Fe[Formula: see text]Cu1Mo3Si[Formula: see text]B9 alloy. Cu is an element promoting ultrafine structure and crystallization progresses, it causes the grain size of the [Formula: see text]-Fe(Si) phase to decrease suddenly, the volume fraction of [Formula: see text]-Fe(Si) phase to increase only by adding 0.5 at.% Cu. Also, Mo causes the grain size of [Formula: see text]-Fe(Si) phase to decrease like Cu, while suppressing the increase of the volume fraction of [Formula: see text]-Fe(Si) phase, Si has no little effect on the grain size of [Formula: see text]-Fe(Si) phase, diffuses into the inner part of [Formula: see text]-Fe(Si) phase upto Si 13.5 at.%, but suddenly increases grain size above Si 13.5 at.%. The microstructure of Fe[Formula: see text]Cu1Mo3Si[Formula: see text]B9 alloy is nearly completed at 520[Formula: see text]C for about 20 min, the grain size is approximately 13.8–14.1 nm, the volume fraction of [Formula: see text]-Fe(Si) phase is within 61–66%, initial permeability at 1 kHz is within 59,800–61,100.

Enhanced Mechanical and Corrosion Performance by Forming Micro Shear Bands in Cold Forged Mg-Gd-Y-Zr Alloy

Forging at room temperature was applied on the per-extruded Mg-Gd-Y-Zr alloy to investigate the effect of cold forging on the microstructure, mechanical properties and corrosion resistance of the alloy. Abundant micro shear bands with misorientations of 2–15° were generated in the as forged alloys. Tremendous enhancement in tensile yield strength was achieved after forging. With a quantitative investigation, micro band boundaries were considered to provide a great contribution to the reinforcement. The ultrafine structure resulting from the formation of micro shear bands led to increased corrosion resistance of the alloy.

Luders Deformation Mechanisms on Yield Point in X80 Grade Pipeline with Ultrafine Structure

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