The dynamic strain aging (DSA) phenomenon that occurs in some materials under certain temperature and strain rate conditions can cause plastic strain localization in the form of Portevin-Le Chatelier (PLC) bands. Carbon-manganese steels are used commonly and frequently in construction because of their ductility, low cost and ability to form mechanically. In these steels, the DSA phenomenon occurs for common quasi-static strain rates from 150 to 300°C, which makes band observation complicated. PLC bands on a carbon-manganese steel that was sensitive to DSA were studied using an infrared camera. Specimen heating was achieved using an induction furnace (with an adapted coil inductor), which allows for temperature recording during tensile tests. Thermography with an infrared camera was used to estimate the band characteristics and increments in band plastic strain, which is an important parameter for material behavior identification necessary for DSA phenomenon modeling. This technique had been developed only for PLC phenomenon observation at ambient temperature on aluminum alloys. Band characteristics on the carbon-manganese steels have been compared with results obtained previously on aluminum alloys.

In this work, a method to compute explicit thermal solutions for laminated and sandwich beams with arbitrary heat source location is developed. The temperature is written as a sum of separated functions of the axial coordinate x , the transverse coordinate z and the volumetric heat source location x 0. The derived non-linear problem implies an iterative process in which three 1D problems are solved successively at each iteration. In the thickness direction, a fourth-order expansion in each layer is considered. For the axial description, classical Finite Element method is used. The presented approach is assessed on various laminated and sandwich beams and comparisons with reference solutions with a fixed heat source location are proposed. Based on the accurate results of the thermal analysis, thermo-mechanical response is also addressed using also a separated representation.

The temperature fields on the die surface measured by an infrared camera during High Pressure Die Casting process. It is compared to the simulation which has already been adjusted by 8 thermocouples. The directional emissivity of the mold surface is measured in the spectral range [7.5-13µm] between 63-174°C. We obtained an almost uniform emissivity from normal direction to the surface up to 60°. The surface condition is a key point to achieve a reliable temperature field. Similar areas in the temperature fields are identified between experiments and simulation although the measurement conditions are particularly difficult in the foundry environment.

Due to an ultra-low thermal expansion, Zr 2 O(PO 4) 2 could find many applications as a thermal shock resistant material. To this end, ceramic processing is a key step in order to reach best properties. In this work, Zr 2 O(PO 4) 2 was sintered by conventional sintering and by the spark plasma sintering technique (SPS) with and without additive. Samples made by conventional sintering with ZnO as sintering aid have a maximum relative density of around 92 %. Microstructure is composed of large grains and microcracks can be observed. When doped with 5 wt. % of MgO, samples can be densified by SPS up to 99.6 % of the relative density and the grain size maintained between 0.5 and 1.5 m. Thermal conductivity and Vickers microhardness were investigated as a function of the microstructure. Best values were obtained for the ceramic doped with 5 wt.% MgO and sintered by SPS, thanks to a fine microstructure and a small amount of residual microcracks.

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