Papers by Author: Sheng Yang

Abstract: microstructures, aging hardness, mechanical properties of Mg-9Gd-4Y-0.3Zr alloys were investigated. The microstructure is a typical dendritic structure of as-cast sample, The aging test of extruded samples were carried at a temperature rang of 200-300°C and at a different aging time. The aging peak hardness is about 120HV, tensile strength was tested at temperature 25°C, 200°C, 250°C and 300°C, tensile strengths are 375 Mpa, 364 Mpa, 329 Mpa, 286 Mpa respectively, the maximum elongation is 13.32% at 300°C. The fracture mode is mainly microvoid coalescence fracture combination the brittle cleavage fracture at room temperature, and microvoid coalescence fracture at 200-300°C.

Abstract: The exfoliation corrosion behavior of 2524 aluminum alloy was studied by Transmission Electron Microscope (TEM), hydrogen evolution and Electrochemical impedance spectroscopy (EIS) . The results showed that 2524 aluminum alloy was very susceptible to exfoliation corrosion and the exfoliation corrosion appeared after 24 h. EIS could better explain the exfoliation corrosion than hydrogen evolution. Exfoliation corrosion kinetics included accelerated formation of pitting, quick development of pitting, retarded formation of exfoliation and steady development of exfoliation.

Abstract: The microstructures and corrosion properties of AZ91 magnesium alloy with trace additions of Sc were investigated. The microstructures were observed by OM and SEM, and the corrosion properties were studied by electrochemical technique. The results show that the alloys with Sc form a second-phase Al3Sc, the grains become finer with the increasing content of Sc and the microstructure is the finest when Sc content up to 0.6%, the corrosion resistant of alloy combining with Sc is improved.