다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Research advances of magnesium and magnesium alloys worldwide in 2021

Microstructural characteristics and mechanical properties of the hot extruded Mg-Zn-Y-Nd alloys

The microstructure evolution and its influence on the mechanical properties are investigated in a hot-corrosion resistant Ni-based superalloy during long-term thermal exposure. It is found that the tertiary gamma' phase disappears and the secondary gamma' phase coarsens and coalesces gradually, which acts as the main reason for the decreasing of strength at both room temperature and 900 degrees C. During exposure, the grain boundary coarsens from discontinuous to half-continuous and finally to continuous structure. The optimum half-continuous grain boundary structure composed of discrete M23C6 and M3B2 wrapped by gamma' film leads to the elongation peak at room temperature in the thermally exposed specimens. At 900 degrees C, the increase in the elongation is attributed to the much softer matrix and the formation of microvoids. The behavior of primary MC decomposition is a diffusion-controlled process. During exposure, various derivative phases including M23C6, gamma', eta, M6C and sigma sequentially form in the decomposed region. Primary MC decomposition and the precipitation of sigma phase have little effect on the mechanical properties due to their low volume fractions. (C) 2012 Elsevier Ltd. All rights reserved.

The microstructure evolution and its effect on the mechanical properties of a hot-corrosion resistant Ni-based superalloy during long-term thermal exposure

Effects of annealing treatment on microstructure and tensile behavior of the Mg-Zn-Y-Nd alloy

Tensile, creep behavior and microstructure evolution of an as-cast Ni-based K417G polycrystalline superalloy

Effect of extrusion process on the mechanical and in vitro degradation performance of a biomedical Mg-Zn-Y-Nd alloy.

In the present study, the effect of Zn content on the microstructure and deformation behavior of the as-cast Mg–Zn–Y–Nd alloy has been investigated. The results showed that as Zn content increased, the volume fraction of secondary phases increased. Moreover, the phase transformation from W-phase to W-phase and I-phase occurred. In the as-cast state, W-phase exists as eutectic and large block form. When Zn content increases to 6 and 8% (wt%), small I-phase could precipitate around W-phase particles. Additionally, the effect of Zn content on the tensile properties and deformation behavior varies with the testing temperature. At room temperature, the tensile strength increases with Zn content, whereas the elongation increases initially and then decreases. At 250 °C, as Zn content increases, the tensile strength decreases initially and then increases slightly, whereas the elongation decreases. At 350 °C, the elongation increases with Zn content, whereas the tensile strength decreases initially and then increases slightly.

Ziyang Hu

Papers

Microstructural characteristics and mechanical properties of the hot extruded Mg-Zn-Y-Nd alloys

Effects of annealing treatment on microstructure and tensile behavior of the Mg-Zn-Y-Nd alloy

Tensile, creep behavior and microstructure evolution of an as-cast Ni-based K417G polycrystalline superalloy

Effect of extrusion process on the mechanical and in vitro degradation performance of a biomedical Mg-Zn-Y-Nd alloy.

Influence of Zn Content on Microstructure and Tensile Properties of Mg-Zn-Y-Nd Alloy