Stress-induced thermoelastic martensitic transformations and functional properties in [011]-oriented NiTiHfPd single crystals

The stress-induced martensitic transformation in the [011]-oriented Ni45.3Ti29.7Hf20Pd5 (at. %) single crystals in as-grown, homogenized and aged states were investigated in compression. It is experimentally shown that heat treatments of single crystals result in increase in martensitic transformation temperatures, two-fold decrease in reversible strain and increase in strain-hardening coefficient. As-grown single crystals demonstrate large temperature range of superelasticity (up to 140 K), large reversible strain (up to 4.3%) and large work output in comparison with homogenized and aged crystals

The effect of subsequent stress‐induced martensite aging on the viscoelastic properties of aged NiTiHf polycrystals

This study investigated the effect of stress‐induced martensite aging under tensile and compressive stresses on the functional and viscoelastic properties in Ni50.3Ti32.2Hf17.5 polycrystals containing dispersed H‐phase particles up to 70 nm in size obtained by preliminary austenite aging at 873 K for 3 h. It was found that stress‐induced martensite aging at 428 K for 12 h results in the appearance of a two‐way shape memory effect of −0.5% in compression and +1.8% in tension. Moreover, a significant change in viscoelastic properties can be observed: an increase in internal friction (by 25%) and a change in elastic modulus in tensile samples. The increase in internal friction during martensitic transformation after stress‐induced martensite aging is associated with the oriented growth of thermal‐induced martensite. After stress‐induced martensite aging, the elastic modulus of martensite (EM) increased by 8 GPa, and the elastic modulus of austenite (EA) decreased by 8 GPa. It was shown that stress‐induced martensite aging strongly affects the functional and viscoelastic properties of material and can be used to control them

Orientation dependence of superelasticity in quenched high-nickel Ti51.8Ni single crystals

The orientation dependence of the functional and mechanical properties of quenched Ti-51.8at.%Ni single crystals, undergoing a strain-glass transition upon cooling/heating was investigated. It was found that a compressive stress above 800 MPa leads to the B2-B190 martensitic transformation (MT), regardless of orientation. In the high-strength [0 0 1]-orientation, superelasticity (SE) was observed at 203–248 K, with a reversible strain of 2.3%. Degradation of SE at deforming stresses r > 1000 MPa was associated with the formation of {1 1 3}B2 twins during the reverse MT. In the low-strength 1 1 1-orientation, the formation of stress-induced B190 -martensite occurred simultaneously with the plastic deformation of the B2-phase (due to the formation of reorientation bands and dislocation slip) and a reversible strain was not observed

The effect of stress-induced martensite aging in tension and compression on B2–B19′ martensitic transformation in Ni50.3Ti32.2Hf17.5 high-temperature shape memory alloy

The present study investigates the high-temperature shape memory effect (SME) in heterophase Ni50.3Ti32.2Hf17.5 polycrystals with nanosized H-phase particles after stress-induced martensite (SIM) aging in tension and compression. SIM aging created the conditions for fully reversible two-way SME with a strain of up to 50% of the one-way shape memory strain. SIM aging altered the viscoelastic properties of material, in particular, the elastic moduli of austenite and martensite increased, as did internal friction. Increased interface mobility is suggested as the reason for internal friction growth

Semantic analysis of latin names of the most common liver diseases

The purpose of the study is to find information about Latin medical terms related to hepatology.Цель исследования – найти информацию о латинских медицинских терминах, относящихся к гепатологии, и проанализировать их

Elastocaloric effect in aged single crystals of Ni54Fe19Ga27 ferromagnetic shape memory alloy

In the present study, the effect of 0-phase dispersed particles on both the L21(B2)-10M/14ML10 martensitic transformations and the elastocaloric effect in aged Ni54Fe19Ga27 single crystals oriented along the [001]-direction was investigated. It was experimentally shown that aging strongly affects the elastocaloric properties of these crystals. The precipitation of semi-coherent 0-phase particles up to 500 nm in size in the crystals aged at 773 K for 1 h leads to a 1.4 times increase in the operating temperature range of the elastocaloric effect up to DTSE = 270 K as compared with the initial as-grown crystals (DTSE = 197 K). The adiabatic cooling values DTad are similar for the as-grown crystals DTad = 10.9 (0.5) K and crystals aged at 773 K DTad = 11.1 (0.5) K. The crystals containing temperature range of DTSE = 255 K with slightly smaller adiabatic cooling DTad below 9.7 (0.5) K. The aged [001]-oriented Ni54Fe19Ga27 single crystals demonstrate high cyclic stability: the number of cycles does not influence the adiabatic cooling values and parameters of loading/unloading curves regardless of the particle size. The ways to improve the elastocaloric cooling parameters and stability of the elastocaloric effect by means of dispersed particles in the NiFeGa ferromagnetic shape memory alloy were discussed.В ст. ошибочно: Nikita S. Suriko

The Effect of Subsequent Stress-Induced Martensite Aging on the Viscoelastic Properties of Aged NiTiHf Polycrystals

This study investigated the effect of stress-induced martensite aging under tensile and compressive stresses on the functional and viscoelastic properties in Ni50.3Ti32.2Hf17.5 polycrystals containing dispersed H-phase particles up to 70 nm in size obtained by preliminary austenite aging at 873 K for 3 h. It was found that stress-induced martensite aging at 428 K for 12 h results in the appearance of a two-way shape memory effect of −0.5% in compression and +1.8% in tension. Moreover, a significant change in viscoelastic properties can be observed: an increase in internal friction (by 25%) and a change in elastic modulus in tensile samples. The increase in internal friction during martensitic transformation after stress-induced martensite aging is associated with the oriented growth of thermal-induced martensite. After stress-induced martensite aging, the elastic modulus of martensite (EM) increased by 8 GPa, and the elastic modulus of austenite (EA) decreased by 8 GPa. It was shown that stress-induced martensite aging strongly affects the functional and viscoelastic properties of material and can be used to control them