The shape memory effect exhibited by Fe-Mn-Si based alloys is due to the y(f.c.c.)-e(h.c.p.) martensitic transformation. The martensitic transformation induced by traction at room temperature in a Fe16Mn-9Cr-5Si-4Ni (%mass) is here studied by optical microscopy, scanning electron microscopy, transmission electron microscopy and scanning tunnelling microscopy. The martensitic microstructure and ...

It is increasingly important in the context of high–manganese steels of the kind that lead to twinning–induced plasticity to be able to estimate the temperature at which ε–martensite forms when austenite is cooled. We find that the thermodynamic method used in similar calculations for α martensite cannot in many cases be implemented because of apparently imprecise thermodynamic data, a conclusi...

The formation of stress-induced α′′ martensite in a metastable β Ti-Mo-based alloy has been studied using X-ray diffraction and transmission electron microscopy. The martensite nucleates heterogeneously at pre-existing sub-grain boundaries by dissociation of the boundary dislocations which bow out on inclined planes. The growth of martensite laths from the resultant stacking faults occurs by th...

Modulated phases occur in numerous functional materials like giant ferroelectrics and magnetic shape-memory alloys. To understand the origin of these phases, we employ and generalize the concept of adaptive martensite. As a starting point, we investigate the coexistence of austenite, adaptive 14M phase, and tetragonal martensite in Ni-Mn-Ga magnetic shape-memory alloy epitaxial films. We show t...

The experimental facts on the stabilisation of martensite in copper base shape memory alloys, of interest to the scientific investigator and the practical alloy processor and user are reported. Factors that have an influence on stabilisation are considered in this respect. The mechanisms proposed in the literature to explain stabilisation are critically examined.

Abstract Flow forming and inertia friction welding (IFW) have been widely used as manufacturing processes that produce high-value engineering components. Combining these two advanced facilitates the fabrication of near-net shape components leading to optimized designs. This study introduces joining flow-formed seamless tubes MLX®19 maraging steel using IFW process fabricate a component in landi...

Microstructural morphology is known to have a significant impact on the mechanical properties of dual-phase steels. A fine ferrite grain size and random distribution small second phase islands are desirable provide superior isotropic compared banded that typical for this type steel. rapid alloy prototyping (RAP) facility has been used investigate three different DP 800 variants by systematicall...

The evolution of the dislocation densities in martensite and austenite during quench a low-carbon (0.215 wt% C) steel is investigated situ by mean High Energy X-Ray Diffraction experiment on synchrotron beamline. line configuration offers an excellent time resolution well adapted to studied martensitic transformation kinetics. density dislocations increases as proceeds confirming that are not h...