The problem of voids and porosity has long plagued the dental technician. Many times an otherwise acceptable casting has had to be discarded because voids or porosities have developed within the casting. Because of numerous variables a technician often does not know the cause of the casting failure. Many investigators have studied variables that may affect the occurrence of voids and porosities...

A three-dimensional mathematical and physical model coupling with the heat transfer and the flow of molten metal in the centrifugal casting of the high speed steel roll was established by using CFD software FLUENT. It can be used to analyze the distribution of the temperature filed and the flow filed in the centrifugal casting under the gravity, the electromagnetic stirring force and the centri...

The transport of fluid, heat ,and particles (bubbles and solid inclusions) in flowing molten steel is investigated in steel refining ladles, the continuous casting tundish, continuous casting mold and strand, and steel ingot casting processes. The two-equation k-ε model is used to simulate the turbulence. Multiphase fluid flow is numerically simulated with a Lagrangian-Eulerian approach, an Eul...

Mold powders in continuous casting of steel contain fluorine through mainly CaF2 and occasionally NaF and Na3AlF6. Fluorine develops dangerous gases such as SiF4 and HF at high temperatures. In this study, CaF2 is partly replaced by substances such as Na2CO3, ZnO and Fe2O3.Sulfur free Portland cement clinker containing gypsum was used as a new product base. These additions developed comparable ...

Clogging of the tundish nozzle is a major castability problem in continuous casting of steel for several reasons. Firstly, clogging increases the frequency of operation disruptions to change nozzles or tundishes or even to stop casting. These extra transitions increase operating cost, decrease productivity, and lower quality. Secondly, clogging can lead directly to a variety of quality problems...

A viscoplastic deformation model considering material damage is used to predict hot tear formation in a permanent mold magnesium alloy casting. The simulation model calculates the solid deformation and ductile damage. The viscoplastic constitutive theory accounts for temperature dependent properties and includes creep and isotropic hardening. Ductile damage theory is used to find mechanically i...

Electromagnetic braking (EMBr) greatly influences turbulent flow in the continuous casting mold and its transient stability, which affects level fluctuations and inclusion entrainment. Large eddy simulations are performed to investigate these transient flow phenomena using an accurate numerical scheme implemented on a graphics processing unit. The important effect of the current flow through th...

Abstract — Ceramic shell investment casting process is used to produce high quality metal products with relatively close dimensional tolerances. The refractory primary slurry that is applied to the surface of the pattern assembly, to pick up its surface details plays a very important role in ceramic shell investment casting process (CSICP). It produces a smooth, acceptable surface finish of the...

Rapid tooling technology is regarded as an important method of reducing the cost and time to market in a new product development process. Silicone rubber mold is frequently used in indirect tooling. Automatic vacuum casting system is widely used to degas in the manufacturing of silicon rubber mold, but the cost of hardware is very expensive. A low-cost automatic vacuum degassing system is desig...