Twinned substructure in lath martensite was induced the interstitial free (IF) steel via a high pressure thermal cycle (heating up to 1100 ℃ and holding for 30 min, cooling at 10 ℃/s room temperature under of 4 GPa). Experimental observations theoretical simulation confirm that twinned has origin related variants rather than bcc {112} 〈111〉 twins, while extra diffraction spots were caused by cr...

Magnetic Shape-Memory (MSM) materials are a new category of actuator materials with the potential to produce both large actuator strain and rapid response. To explore the possibility of developing MSM materials based on Fe-Ni-Co-Ti alloys, the effects of chemical composition (Co/Ni ratio) and ausaging on microstructure and magnetic shapememory response were studied. A suitable choice of chemica...

Many crystalline materials exhibit twinned microstructures, where well-defined orientation relationships define the special symmetry between different, elastically anisotropic twin variants. When such twins are subjected to external loading, additional internal stresses necessarily occur at the twin boundaries in order to maintain compatibility. These compatibility stresses are constant inside ...

We have constructed a complete hydrodynamic theory of nucleation and growth in a one–dimensional version of an elastic shear martensitic transformation with open boundary conditions where we have accounted for interfacial energies with strain–gradient contributions. We have studied the critical martensitic nuclei for this problem: Interestingly, the bulk critical nuclei are twinned structures, ...

The damping characteristics of Ti50Ni50-xCux (x = 0~30 at.%) shape memory alloys (SMAs) at a low frequency have been studied using a dynamic mechanical analyzer. The magnitude of the tan δ value and the values of the storage modulus (E₀) softening/hardening and the strain variation exhibited in B2↔B19 transformation are all higher than those in B2↔B19' transformation. The larger E₀ softening/ha...

Using first-principles calculations, we investigated the impact of applied stresses and alloying elements on ferrous martensite nanodomains. In non-alloyed martensite, procedure revealed that twinned states can be stabilized depending stresses, leading to several possible crystallographic structures: body-centered tetragonal (BCT) oblate, orthorhombic (BCO), or BCT prolate. alloyed confirmed ex...

A novel concept of varying the strain hardening rate a medium Mn steel with 8 wt.% by duration intercritical anneal after hot rolling was explored. It found that stability austenite phase showed an inverse square root relationship annealing and maximum linear stability. The change in attributed to continuous enrichment increasing duration. Twinned martensite also be most likely product martensi...

The effect of ageing process at 1073.15 K on the athermal phase transformation in different nanograins (4.5, 6 and 9 nm) Nickel–Titanium shape memory alloy is studied using molecular dynamics simulations. martensitic start temperature transformed martensite volume decrease with decreasing grain size. two-stage intermediate formation observed only smallest (4.5 where a single variant formed. On ...

In the present research, microstructure and mechanical properties of low-density Fe-0.72Mn-3.7Al-0.53C steel were investigated after solution treatment at 900 °C, 1000 1110 °C 1200 for 1 h. The density is about 7.0 g·cm−3 due to addition a higher content aluminum elements. was characterized by scanning electron microscopy (SEM) transmission (TEM), behavior analyzed room temperature tensile test...