Thermoelectric Method of Plastic Deformation Detection

The paper presents an approach of non-destructive testing of plastic deformation of metals and alloys by measuring the differential thermoelectric power. Using the developed measuring device for this purpose, measurements of thermoelectric power were performed on several types of steels that are used in the manufacture of product pipelines. Incisions were made on the surface of the testes objects, for the purpose of experimental detection of the place of plastic deformation. In the process of stretching, thermoelectric power was measured at and near the place of the proposed plastic deformation. During the process of stretching the sample, the decrease in thermoelectric power measurement occurs almost linearly. The maximum change in the thermoelectric power measurement of the tested object was observe before the rapture discontinuity.

Plastic Deformation and Thermal Induced Phase Transformation in 2507 Type Super Duplex Stainless Steel

The aim of this study was to investigate the effect of the previously applied cold rolling and the latter heat treatment for the eutectoidal decomposition of δ-ferrite in 2507 type superduplex stainless steel (SDSS). The samples were cold rolled at seven different deformation rates which was followed by heat treatment at were 20, 700, 750, 800 and 850 °C temperatures. The rolled and heat treated samples were investigated by hardness tester, AC magnetometer and thermoelectric power measurement. The activation energy of the decomposition was determined by the Arrhenius equation through the results of the AC magnetometer measurement.

Thermoelectric Power Measurement of Catalyst-free Si-doped GaAs Nanowires

ABSTRACTSi-doped GaAs nanowires (NWs) were grown on (111)Si substrate by MBE-VLS method. The electrical characteristics of the GaAs NWs were measured. A joule heater was arranged near the tip of NW for making the gradient of substrate temperature. The obtained Seebeck coefficient of the GaAs NW increases linearly with a rise in temperature. The thermoelectric power of the Si doped GaAs NW was determined by the hole diffusion. It was estimated that the hole density in the Si-doped GaAs NW at room temperature was 5.9×1018 cm-3 from the slope of the temperature dependence of the Seebeck coefficient in the Si-doped GaAs NW. At room temperature, the Seebeck coefficient, thermoelectric power factor, and thermoelectric figure of merit (ZT) were 429 μV/K, 271μW/mK2, and 1.5×10-3, respectively.