H.Y. Tu

Material research for planar SOFC stack

In the present paper, material research dealing with electrolyte, anode, cathode, interconnect and sealant for planar solid oxide fuel cell (SOFC) stack has been reported. Depending on the materials research, a two-cell stack and a 10-cell stack with cell size of 40x40 mm 2 were established and tested. The 10-cell stack at 1000 °C showed a power output of about 10 W and a power density of about 110 mW/cm 2 .

Research on planar SOFC stack

The present paper reports the achievement of solid oxide fuel cell (SOFC) stack research in Shanghai Institute of Ceramics, Chinese Academy of Sciences. Single column SOFC stacks with internal manifolding and cross-flow structure were established and successfully operated. The investigation of materials and components relating the stacks are also briefly described.

Study on the solid solubility of Al in the melilite systems R2Si3 − xAlxO3 + xN4 − x with R = Nd, Sm, Gd, Dy and Y

Abstract The solubility of aluminium in the nitrogen-containing melilite structure has been studied by preparation of specimens of the general formula R 2 Si 3 − x Al x O 3 + x N 4 − x with R = Nd, Sm, Gd, Dy and Y by hot pressing and pressureless sintering techniques in the temperature interval 1600–1750 °C. For elements with large ionic radii, i.e. R = Nd and Sm, up to one Si can be replaced by Al, but the solubility limits in melilite solid solutions decrease with decreasing the ionic radii. Consequently, yttrium-melilite had the lowest observed aluminium solubility (x ≈ 0.6) in rare earth elements-melilite solid solutions.

Glass-forming region in the Sm-Si-AI-O-N system

We report the glass-forming region at 1700°C for N-rich compositions of the Sm-Si-Al-O-N system

Chemical compatibility of RE0.6M0.4Mn0.8Co0.2O3-δ (RE = La, Pr, Nd, Sm and Gd; M = Sr and Ca) with yttria stabilized zirconia

Abstract The chemical compatibility of one new series, RE 0.6 M 0.4 Mn 0.8 Co 0.2 O 3-δ (RE=La, Pr, Nd, Sm and Gd; M=Sr and Ca), with yttria stabilized zirconia (YSZ) has been examined. Powder mixtures of perovskites and YSZ were annealed at 1200° for 24h in air. RE 0.6 M 0.4 Mn 0.8 Co 0.2 O 3-δ showed different compatibility towards YSZ for M=Sr and Ca, respectively. The formation of SrZrO 3 was identified by X-ray diffraction analysis as a reaction product for RE 0.6 Sr 0.4 Mn 0.8 Co 0.2 O 3-δ . In contrary, there is no reaction product for RE 0.6 Ca 0.4 Mn 0.8 Co 0.2 O 3-δ . EDX analysis revealed that there is a larger difference between the solubility of Sr and Ca in YSZ. The bond-valence model was used to discuss the different compatibility of Sr and Ca series perovskites with YSZ. The present studies also showed that the formation of SrZrO 3 was favored for larger disorder effect due to size difference between A-site RE 3+ and Sr 2+ in RE 0.6 Sr 0.4 Mn 0.8 Co 0.2 O 3-δ .

Compositional design of α′-β′-YAG (Y3Al5O12) multiphase sialon ceramics

Abstract The sinterabilities of α′-β′-YAG (Y 3 Al 5 O 12 ) multiphase sialon ceramics in the α ′- β 0 (β-Si 3 N 4 )- β 10 (β-sialon, z = 0.8)-YAG phase compatibility region of the Y, Si, Al O , N system have been studied with the aid of computerised factor analysis method, which is one of the most powerful techniques in chemometrics, using the compositions of materials as the characteristic parameters. One of the optimized compositions has been fabricated via gas pressure sintering and the results are encouraging for obtaining materials with a combination of high strength, fracture toughness and hardness and retention of high temperature strength up to 1350 °C.

Prediction of glass forming region in the SmSiAlON system with an artificial neural network

Abstract The glass-forming region in the SmSiAlON system at 1700 °C was studied by using an artificial neural network (ANN). An artificial neural network (ANN) was trained and tested with fifty experimentally determined examples in the investigated system with a back-propagation algorithm. The results of all forty-two examples of the training set and the testing set of eight obtained from the ANN are in good agreement with experiments. The glass-forming boundaries on the planes of 25, 27.5, 30, 32.5, 35 and 40 eq% N were predicted with the trained network, which indicates the tendency of contraction towards the Si-rich region with increasing nitrogen content. The approach shows a considerable promise for applications to determination of nonlinear boundaries of glass-forming regions in complex material systems, in cases where thermodynamic calculations of phase equilibria are not effective.