Optimisation of the Zr:Ti ratio in bulk lead zirconate titanate for templated grain growth using BaTiO3 seeds

Presented here is a proof of concept demonstration of the templated grain growth (TGG) process for the development of [001]c fibre-textured Pb(ZrxTi1-x)O3 (PZT) ceramics. BaTiO3 platelets (5 and 10 vol.%) were selected to seed growth of highly oriented PZT grains resulting in texture fractions as high as 94%. The TGG process in PZT was observed to be critically dependent upon the addition of excess PbO liquid phase and may be driven by BaTiO3 dissolution into the matrix. Solid solution incorporation of BaTiO3 during sintering resulted in a structural shift away from the PZT morphotropic phase boundary (MPB) and a decrease in Curie temperature (TC) by ~ 40 °C which still exceeded > 300 °C. Modification of the Zr:Ti ratio in untextured ceramic analogues was explored as a strategy to tailor dielectric, ferroelectric, and electromechanical properties. An initial PZT matrix composition of Pb(Zr0.56Ti0.44)O3 resulted in a final bulk Pb0.947Ba0.053(Zr0.531Ti0.469)O3 ceramic having MPB-like properties of d33 = 453 pC/N, tan δ = 0.017, TC = 340 °C, and Ec = 9.3 kV/cm, which was observed to be similar to commercial ‘soft’ PZT-5A1

Tech United Eindhoven @Home 2022 Champions Paper

This paper provides an overview of the main developments of the Tech United Eindhoven RoboCup@Home team. Tech United uses an advanced world modeling system called the Environment Descriptor. It allows for straightforward implementation of localization, navigation, exploration, object detection &amp; recognition, object manipulation and human-robot cooperation skills based on the most recent state of the world. Other important features include object and people detection via deep learning methods, a GUI, speech recognition, natural language interpretation and a chat interface combined with a conversation engine. Recent developments that aided with obtaining the victory during RoboCup 2022 include people and pose recognition, usage of HSR’s display and a new speech recognition system.</p

The Effect of Heat Generation on the Development of Vermicular α-Al ₂O₃ in Alumina Films

AbstractThe transformation of transition aluminas (i.e. θ-A12O3) to α-A12O3 results in an interconnected, porous microstructure that is commonly described as ‘wormy’ or‘vermicular’. The effect of heat generated during the exothermic transformation at the θ-Al2O3/α-Al2O3 interface on the development of the vermicular α-A12O3 morphology was analyzed in boehmite-derived thin films. The vermicular structure may arise in an analogous manner to the thermal dendrites formed in metals during solidification. However, the analysis shows that heat generation and transfer at the interface does not play a significant role in the development of α-A12O3 dendrites.</jats:p