Inorganic binder used in casting process has the advantages of low odor, labor-friendly conditions, and relatively low cost, which is one of the main development directions for casting molding materials in the future. However, compared to organic binders (such as resin binders), inorganic binders exhibit lower bonding strength and are more sensitive to environmental humidity. This sensitivity poses challenges, particularly in the reclamation of used sand, thus limiting their broader application. In this paper, the research and application status of inorganic binders (mainly silicate inorganic binders) and their curing methods are summarized. In addition, the research and application of phosphate inorganic binders and 3D printing inorganic binders that are being developed are introduced. Meanwhile, a detailed comparative analysis is conducted on the challenging issue of “reclamation for used sand” in the application of inorganic binders. Finally, the development direction of inorganic binders is clarified.
Theories on fluidity of alloys based on the solidification mode are not satisfactory in describing fluidity of alloys under high-pressure die casting (HPDC) conditions. To understand the flow-choking mechanisms under HPDC conditions, microstructure in the fluidity test coupons made using a 125-ton HPDC machine was characterized. Pre-solidified dendrites (PSDs), or externally solidified crystals (ESCs), which were formed in the shot sleeve, were found in the runners as well as in the fluidity casting. Surprisingly, a large amount of PSDs are collected in the runner adjacent to the in-gate, forming a PSD core with a thin layer of PSD-less or PSD-free region near the surfaces of the runner due to Magnus effect. Analytical calculations were performed to estimate the pressure drop for molten aluminum flowing through the mushy PSD zone. The results indicate that the pressure drop is comparable to the maximum pressure that was used for injecting molten metal to fill the casting. When the pressure drop is equal to the pressure driving the mold filling, the metal ceases to flow. Thus, it is the PSDs that are responsible for the choking of mold filling either mechanically at the in-gate or providing a pressure drop high enough to resistant fluid flow.
By designing thin plate castings with different wall thicknesses, the influence of different wall thicknesses on the microstructure and properties of the Ni 3 Al superalloy was studied. As the wall thickness increased,the secondary dendrite wall of the alloy increased, and the segregation of Al, Ti, Hf, Mo, Cr, W and other elements in the structure changed. The tensile strength and tensile ductility of the alloy significantly increased.
约克郡一家"标志性"工厂谢菲尔德铸锻公司锻造厂已开始拆除,以促进英国最大的开式模锻生产线的建设.谢菲尔铸锻公司德锻造厂位于伯利兹德路以北的部分场地正在有序拆除,以便为一条13 000 t的重型开式模锻生产线的锻造厂创造空间,该锻造生产线厂将安置在位于谢菲尔德至梅多霍尔铁路线附近的一座12 700 m2的新建筑中.其中废弃的铸锻厂建筑将为新工厂让路,这些废弃的建筑可以追溯到维多利亚时期.这一新工厂将开创欧洲最为高效的开式模锻加工,也是英国同类模锻厂中规模最大的.
