Controlled Crystallization of Amorphous Si3N4by Ti and CI Additives

Thin films of amorphous Si₃N₄ were prepared by the rf-sputtering method, and the effects of titanium and chlorine additives on its crystallization were examined. When Ti-doped amorphous Si₃N₄ was heated, TiN precipitated at >1100°C; the TiN precipitates promoted the conversion of amorphous Si₃N₄ to β-Si₃N₄. Chlorine led to preferential conversion of amorphous Si₃N₄ to α-Si₃N₄.     

Coupled Analysis by Viscoelastic Body with Rigid Body for Design of MRE Soft Actuator

The magneto rheological elastomer (MRE) is composed of silicone elastomers and ferromagnetic powders that are responsible for its ferromagnetic and viscoelastic properties. The shape and the stiffness of the MRE change depending on the magnetic field. Therefore, it is expected to be used for artificial muscle or damping material. We developed a coupled analysis method by combining the moving particle semi‐implicit/simulation (MPS) method with the finite element method (FEM) for the design of the MRE actuator. However, this method does not take into account a rigid body. Therefore, when analyzing the coil embedded in the MRE, it was difficult to calculate parameters such as the coil rotation and position. Therefore, this paper presents a numerical method for MRE actuator analysis by coupling MPS method with FEM to arrive at a calculation method for a rigid body. The numerical algorithm is described and the calculated results are shown.     

CrO2-Cr2O3 Phase Boundary Under High O2 Pressures

The phase boundary between CrO₂ and Cr₂O₃ was reinvestigated under high O₂ pressures by using a new type of gas compressor. The boundary curve can be represented as log Po₂= 7.16-(3579/ T ). Using the observed data, Δ G °, Δ H °, and Δ S ° for the reaction 2CrO₂⇋Cr₂O₃+½O₂ were calculated to be: Δ G °= -(1.55/100) T +7.60 kcal/mol, Δ H °= -8.19 kcal/mol, and Δ S °= (-15.8/ T )+0.0155 kcal/mol.