Ultrafine-grained (UFG) metallic materials processed by severe plastic deformation (SPD) techniques often exhibit significantly higher strengths than those calculated the well-known Hall-Petch equation. These result from fact that SPD processing not only forms UFG structure but also leads to formation of other nanostructural features, including dislocation substructures, nanotwins and nanosized...

The effects of the thickness (t), grain size (d), ratio t/d, and tensile direction on properties were carefully examined using ASTM grade 1 pure titanium having a strong B texture with controlled (0.2–0.4 mm), (20–175 µm), t/d (2.3–19.4). 0.2%-proof stress followed Hall-Petch relationship in each regardless thickness, this indicates that does not depend t/d. On other hand, strength uniform elon...

This paper presents the results of studies on true fracture stresses Al alloy 6101 with an ultrafine-grained (UFG) structure processed by equal channel angular pressing — conform (ECAP-C) method and same after artificial aging (AA state). The grain size in UFG state was about 500 nm. Aging particles Al3Fe were present AA state. Strength yield stress increase as a result formation structure. str...

Metal powder bed fusion (PBF) additive manufacturing (AM) builds metal parts layer by upon a substrate material. The strength of this interface between the and printed material is important to characterize, especially in applications where retained included finished part. Ensuring that original has adequate properties enables use PBF AM process repair existing structures create new using both c...

Industrial pure iron samples were austenitized and quenched (6°C/s cooling to room temperature) under hydrostatic pressure of 3–5 GPa. The morphology, phase transformation strengthening mechanism high-pressure martensite are analyzed by the method SEM, XRD, EBSD, TEM. Lath with hierarchical packet-block-lath structure is induced in industrial high pressure, which keeps Kurdjumov-Sachs (K-S) ori...

Mechanical properties in tension of cobalt have been studied a wide range grain size d using thickness t samples from 125 to 700 ?m. The Hall and Petch (HP) relationship indicates that the yield stress strongly varies for t/d below critical value around 14, highlighting existence multicrystalline regime. behavior becomes almost single crystalline when is lower than 2.5, with very small HP slope...