introduction: the aim of this study was to evaluate the effect of bridge orientation in casting machine on castability and quality of base metal castings. methods: three groups of patterns with different direction and lengths in casting machine were casted and then studied qualitatively and quantitatively using mean and standard deviation in table of frequency. results: larger nodules and poros...

Casting has many process variations depending upon the material, the type of pattern, mould and the pouring technique like sand casting, investment casting, die casting, squeeze casting and lost foam casting. Sand casting is the most widely used process which can be used to produce intricate parts in almost every metal that can be melted. Casting defects analysis is process of finding the root ...

During the continuous casting process, a nonstationary stress state forms in the metal, which is caused by a non-uniform temperature distribution, phase transitions, and the deformation of the stock in a semi-liquid state. Stresses occur also as a results of ferrostatic pressure and the deflection and straightening of the continuous casting. In addition to these phenomena, intensive processes o...

BACKGROUND The thermal expansion of the investment can be restricted by the metal casting ring because the thermal expansion of the ring is less than that of the investment. The ringless casting procedure is in use in clinical dentistry, though there is little scientific data to support its use in fixed partial dentures. In this study, marginal discrepancy of castings produced with the ringless...

A mathematical model of heat transfer in continuous casting copper slabs capable of producing experimental data has been constructed and validated against experimental data provided by the management of Copper Refineries Ltd., Townsville plant in Australia. It has been used to predict the effects of major casting variables; metal temperature, casting speed and metal conductivity. The results ca...

Solidification rate of the casting affects greatly on the microstructure, quality as well as the mechanical properties of the casting. In centrifugal castings solidification rate is faster compared to gravity casting but still solidification depends on various process parameters like, die wall temperature, pouring temperature of the molten metal, wall thickness of the die and also rotational sp...

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...

background and aim: an important criterion for success assessment of implant-supported prostheses is marginal fit. vertical and horizontal discrepancy can result in loosening of the prosthetic screw, crestal bone resorption, peri-implantitis and loss of osseointegration. despite careful attention to waxing, investing, and casting, marginal discrepancies are inevitable. the aim of this study was...

Ceramo-metal dental casting alloys are used for crowns and fixed partial dentures (bridges). Ni-Cr and Co-Cr are base ceramo-metal dental casting alloys and now account for the majority of the fixed metalceramic restorations used clinically. The corrosion of these alloys result in release of elemental components with potential adverse biological reactions. It is of great importance to investiga...

PURPOSE One of the most important factors in evaluating the quality of fixed dental prostheses (FDPs) is their gap. The purpose of this study was to compare the marginal and internal gap of two different metal-ceramic crowns, casting and selective laser sintering (SLS), before and after porcelain firing. Furthermore, this study evaluated whether metal-ceramic crowns made using the SLS have the ...