The strength of four binary systems NaCl-Na 2 CO 3 , KCl-K 2 CO 3 , KCl-NaCl and K 2 CO 3 -Na 2 CO 3 was investigated in order to develop expendable salt core for high pressure die casting processes. Four point bending test was conducted to determine the strength of specimens made from molten salts by using the permanent mold casting technique. The strength of the system NaCl-Na 2 CO 3 was over 20 MPa at the Na 2 CO 3 composition between 20 mol% and 30 mol%, and between 50 mol% and 70 mol%. The highest strength was about 30 MPa at the composition of NaCl-70 mol%Na 2 CO 3 . This strength was 5 times as high as that of commonly used sand cores. The system KCl-K 2 CO 3 also showed 20 MPa in strength. It was observed that there were the primary particles surrounded by the eutectic structure in the solidification structure of the systems NaCl-Na 2 CO 3 and KCl-K 2 CO 3 at the composition where the peak strength was obtained. The presence of the primary particles played an important role to strengthen the structure because the primary particles can prevent or deflect the crack propagation. In contrast to these binary systems, the systems KCl-NaCl and K 2 CO 3 -Na 2 CO 3 were very brittle due to the phase decomposition or other solid-solid phase transformation of the solid solution phase. The strength of these systems was under 6 MPa.
The phase equilibria of the Ni-rich portion in the Ni-Si system were investigated. The phase boundaries between liquid and fcc phases were established by the diffusion couple method and those of fcc and 1 or 2 were determined by the SEM-EDX measurement of two-phase alloys. The liquidus of the present work well agrees with the previous experimental data determined by a thermal analysis. The solidus data are rather different from the previous experimental data, but agree with the thermodynamic calculated phase diagram. This result suggests that the present solidus and liquidus data are consistent with thermodynamic data. The solubility of Si in the fcc phase agrees with some previous experimental data, but disagrees with the thermodynamic calculated phase diagram. This fact suggests that the thermodynamic reassessment for this system is necessary by the CALPHAD approach.
Semi-Solid metal (SSM) processing is now considered a commercially successful
manufacturing route producing millions of near net shape parts per annum for the automotive
industry. Although semi-solid process is currently widely used as a manufacturing process which
produces near net-shape metal component, the processes those used for the preparation of
semi-solid slurry still take a great deal of time, energy and money. Cup cast method – recently
developed by the authors – is able to make semi-solid slurry preparation as easy as pouring water
from a pitcher into drinking glass. In this method globular solid particles are prepared by controlling
the turbulence and heat distribution in the melt through pouring instead of applying certain external
stirring forces, in other common method. In the current study, cup cast method applied to Al-A356
alloy using simple cylinder. Vital factors of this method were optimized by investigating
micro-structures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.