Yang Guanjun

Microstructure and Electrochemical Behavior of La0.8Sr0.2MnO3 Deposited by Solution Precursor Plasma Spraying

Abstract Solution precursor plasma spraying (SPPS) was employed to prepare porous La 0.8 Sr 0.2 MnO 3 (LSM) cathode for solid oxide fuel cell (SOFC). The surface morphology and microstructure of the LSM deposits were characterized by SEM. The phase structure of LSM was analyzed by XRD. The electrochemical behavior was investigated through the impedance spectroscopy. The effect of spray distance and annealing treatment on SPPS LSM microstructure was examined. Annealing at 1050 °C for 2 h in air, the coherent porous films of the perovskite phase with a fine microstructure were presented. The results show that the microstructure of SPPS LSM cathode exhibits a significant influence on the cathode polarization. The lowest specific surface resistance of 0.3Ω·cm 2 is obtained at 1000 °C for SPPS LSM cathode deposited at a spray distance of 60 mm. SPPS is a promising process to fabricate SOFC cathode with tailoring of the desired phase and microstructure.

Microstructure and Mechanical Properties of TiNbZr Alloy during Cold Drawing

Abstract The cold workability of solution-treated TiNbZr biomedical β titanium alloy was investigated. TiNbZr alloy was fabricated by vacuum consumable arc melting furnace. Cold drawing was carried out for further deformation of the studied alloy. During cold drawing, the alloy exhibited excellent workability. Deformation twins appeared when the reduction of cold deformation was around 20%. Dislocations slipping contributed much to plastic deformation in further drawing. The ultimate tensile strength will go up to 1170 MPa and the elongation is larger than 10% when the reduction reaches 80%. Small grains ranging from 20 nm to 50 nm can be obtained when the reduction is 80%.

Characterization of Microstructure and Mechanical Properties of TiNbZr Alloy during Heat Treatment

Abstract TiNbZr alloy was prepared by vacuum consumable arc melting furnace. The effects of solution and aging heat treatment on the microstructure and mechanical properties of this alloy were studied. The results show that ultimate tensile strength over 1000 MPa can be obtained when the alloy is solutioned for 1 h and then aged at 300 and 350 °C. α phase precipitation appears under the condition of the treatment of solution for 1 h, followed by aging at 400 °C and 450 °C. The aging time plays an important part in α phase precipitation. The ultimate tensile strength increases to 850 MPa and the elongation keeps around 11% when the alloy is aged at 400 °C for 9 h.