The effects of inclusions on microstructure, mechanical property, corrosion behavior of Mg-10Gd-3Y （GW103K） alloys by unrefining, MgO ceramic filtering and JDMJ flux refining were investigated, respectively. The res...The effects of inclusions on microstructure, mechanical property, corrosion behavior of Mg-10Gd-3Y （GW103K） alloys by unrefining, MgO ceramic filtering and JDMJ flux refining were investigated, respectively. The results indicate that with decreasing significantly the number and size grade of inclusions for the alloy refined with JDMJ flux, tensile strength and elongation increase; however, the yield strength is less than that of the alloy refined with MgO ceramic filter and unrefined alloy. With the decrease of the inclusions contents, the corrosion rate of the alloys quickly vary from 2.419 mg/（cm 2 ·d） to 1.265 mg/（cm 2 ·d）. After inclusion content is reduced to 0.385%, the corrosion rate has almost no changes. Finally, the relationship between the volume fraction of inclusions and service properties of GW103K alloy under different conditions are established quantitatively.展开更多
The electroslag cast metal features its cleanness,sound structure,consistent composition,smooth surface,high metal yield,excellent mechanical properties and service life.These advantages have been applied to turbine d...The electroslag cast metal features its cleanness,sound structure,consistent composition,smooth surface,high metal yield,excellent mechanical properties and service life.These advantages have been applied to turbine discs,aircraft landing frames,hollow ingot,die billets,crankshaft and cold rolling.展开更多
Polymer aging under environmental conditions causes deterioration of service properties.Understanding the aging behavior and mechanism is important not only for lifetime prediction,but also for material improvement an...Polymer aging under environmental conditions causes deterioration of service properties.Understanding the aging behavior and mechanism is important not only for lifetime prediction,but also for material improvement and development.Therefore,comprehensive characterization of polymer materials during aging is crucial.In this review,various analytical methods for characterization of chemical changes,physical changes and service properties are introduced.Based on that,methods for stabilization evaluation and lifetime prediction,especially sensitive evaluation methods are reviewed.Chemical changes include molecular weight changes by chain scission and crosslinking,functional group changes on the surface and in the bulk,formation of free radicals,formation of small molecular species as the degradation products,and chemical distribution by heterogeneous aging and additives migration.Physical changes include crystallization changes (post-or chemi-crystallization)and morphology changes (cracking,debonding,etc.).Service property changes include deterioration of processability,mechanical properties,electrical properties and appearance.In the end,existing problems and future research perspective are proposed,including relationship between chemical/physical changes and service properties,introduction of modern mathematical and computer tools.展开更多
基金Project(2007CB613701)supported by the National Basic Research Program of ChinaProject(20100470125)by National Science Foundation for Post-doctoral Scientists of ChinaProject(2009021028)supported by Science and Technique Foundation for Young Scholars of Shanxi Province
文摘The effects of inclusions on microstructure, mechanical property, corrosion behavior of Mg-10Gd-3Y （GW103K） alloys by unrefining, MgO ceramic filtering and JDMJ flux refining were investigated, respectively. The results indicate that with decreasing significantly the number and size grade of inclusions for the alloy refined with JDMJ flux, tensile strength and elongation increase; however, the yield strength is less than that of the alloy refined with MgO ceramic filter and unrefined alloy. With the decrease of the inclusions contents, the corrosion rate of the alloys quickly vary from 2.419 mg/（cm 2 ·d） to 1.265 mg/（cm 2 ·d）. After inclusion content is reduced to 0.385%, the corrosion rate has almost no changes. Finally, the relationship between the volume fraction of inclusions and service properties of GW103K alloy under different conditions are established quantitatively.
文摘The electroslag cast metal features its cleanness,sound structure,consistent composition,smooth surface,high metal yield,excellent mechanical properties and service life.These advantages have been applied to turbine discs,aircraft landing frames,hollow ingot,die billets,crankshaft and cold rolling.
基金financially supported by the 2023 High-level Scientific Research Foundation for the Introduction of Talent of Hefei Normal University (No.2023rcjj08)the Research Project of Hefei Normal University (No.2023QN06).
文摘Polymer aging under environmental conditions causes deterioration of service properties.Understanding the aging behavior and mechanism is important not only for lifetime prediction,but also for material improvement and development.Therefore,comprehensive characterization of polymer materials during aging is crucial.In this review,various analytical methods for characterization of chemical changes,physical changes and service properties are introduced.Based on that,methods for stabilization evaluation and lifetime prediction,especially sensitive evaluation methods are reviewed.Chemical changes include molecular weight changes by chain scission and crosslinking,functional group changes on the surface and in the bulk,formation of free radicals,formation of small molecular species as the degradation products,and chemical distribution by heterogeneous aging and additives migration.Physical changes include crystallization changes (post-or chemi-crystallization)and morphology changes (cracking,debonding,etc.).Service property changes include deterioration of processability,mechanical properties,electrical properties and appearance.In the end,existing problems and future research perspective are proposed,including relationship between chemical/physical changes and service properties,introduction of modern mathematical and computer tools.
