The effects of partial replacement Si by Al on the microstructure, tensile properties, and Charpy impact toughness were investigated using 0.2%C-Si/Al-Mn-Cr-B TRIP-aided martensitic steels to promote application galvanized third-generation ultrahigh- high-strength steels. was related microstructural mechanical properties. decreased volume fraction retained austenite increased stability, accompa...

The aim of this article is to analyze nonlinear electro-magneto vibration of a double-piezoelectric composite microplate-system (DPCMPS) pursuant to the nonlocal piezoelasticity theory. The two microplates are assumed to be connected by an enclosing elastic medium, which is simulated by the Pasternak foundation. Both of piezoelectric composite microplates are made of poly-vinylidene fluoride (P...

We present a mathematical model for the laser surface hardening of steel. It consists of a nonlinear heat equation coupled with a system of ve ordinary diierential equations to describe the volume fractions of the occuring phases. Existence, regularity and stability results are discussed. Since the resulting hardness can be estimated by the volume fraction of martens-ite, we formulate the probl...

We present models of the microstructure of martensite that occurs when twinned layers of martensite meet a pure variant. This microstructure often occurs below the A, temperature, with loading that favors the passage from one pure variant of martensite to another. This microstructure gives a mechanism for variant rearrangement. In this microstructure, the layers are observed to pinch down to sh...

The cofactor conditions, introduced in James and Zhang(2005), are conditions of compatibility between phases in martensitic materials. They consist of three subconditions: (i) the condition that the middle principal stretch of the transformation stretch tensor U is unity (λ2 1⁄4 1), (ii) the condition a UcofðU IÞn1⁄4 0, where the vectors a and n are certain vectors arising in the specification ...

the main purpose of this study is to perform numerical simulation of nanofluids as the coolant in vver-440 fuel rod bundle. the fuel rod bundle contains 60 fuel rods with length of 960 mm and 4 spacer grids. in vver-440 fuel rod bundle the coolant fluid (water) is in high pressure and temperature condition. in the present thermo-hydraulic simulation, water-al2o3 nanofluids containing various vo...

introduction: we investigated the difference in left ventricular ejection fraction (lvef) and end-systolic volume(esv) measured by gated myocardial perfusion spect (gspect) in the post-dipyridamole stress and rest periods, and compared the results with the perfusion patterns found in the conventional non-gated tomograms. methods: 297 consecutive patients were studied with post-stress and rest 9...

in the present research, in contrast to the available papers, not only the superelasticity but also the shape memory effects are taken into account in determination of the impact responses. at the same time, in addition to modifying brinson’s model for the shape memory alloys (smas), to include new parameters and loading events, and hertz contact law, distributions of the sma phases are conside...