The purpose of this study was to evaluate mechanical properties, surface characteristics and castability of Zr-14Nb dental castings. The mean 0.2% proof and ultimate tensile strengths of Zr-14Nb were approximately 68% and 76% those of Ti-6Al-7Nb, respectively, while they were comparable to Co-29Cr-6Mo. Elongation of Zr-14Nb was the highest of all alloys tested. The hardened reaction layer was f...

A model is developed that predicts the motion and growth of oxide inclusions during pouring, as well as their final locations on the surface of steel sand castings. Inclusions originate on the melt free surface, and their subsequent growth is controlled by oxygen transfer from the atmosphere. Inclusion motion is modeled in a Lagrangian sense, taking into account drag and buoyancy forces. The in...

COMPUTATIONALMODELING of mechanical behavior during solidification is becoming more important. Thermal and microstructural simulations alone are insufficient to predict the quality of the final product that is desired by the casting industry. Accurate calculation of displacements, strains, and stresses during the casting process is needed to predict residual stress and distortion and defects su...

Elaborate one-dimensional photonic crystals are constructed from a variety of organic and biopolymers, which can be dissolved or melted, by templating the solution-cast or injection-molded materials in porous silicon or porous silicon dioxide multilayer (rugate dielectric mirror) structures. After the removal of the template by chemical dissolution, the polymer castings replicate the photonic f...

The solidification process during squeeze casting is analyzed based on the classical solidification and plastic deformation theory. The linear relationship between punch velocity and the solidification rate is established if the density change of molten meals is neglected. To obtain defect-free castings, the punch velocity should be larger than the solidification rate. The densification mechani...

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...

Casting failures of alloys in dental technology should be the exception, not the rule. They have to be detected in time and associated with possible causes. For the experimental part base metal alloys single tooth restorations were achieved using the conventional lost wax process for casting in order to be evaluated. Some casting defects obtained during the experimental part are exemplified: in...

At present, the qualified rate of large thin-walled magnesium alloy castings is low. In this study, effects mold structure and process parameters were investigated to improve production qualification castings. The filling die was simulated by numerical simulation technology optimize their structure. On basis an optimized structure, using a response surface model, group optimal combinations obta...

In the paper the analysis of wax pattern and casting dimensions changes during each stages of investment casting technology process has been presented. Results of wax patterns and castings of test plate free and restrained contractions dimensions changes research carried out in Department of Foundry Engineering at Brno University of Technology have been presented as well. Moreover obtained resu...