**10. Conclusion**

284 Ceramic Coatings – Applications in Engineering

For a detailed analysis of structural and mechanical casting characteristics after a visual examination, it is necessary to apply some other test methods either. Casting test without destruction may reveal the presence of volume faults in the casting. Microstructural tests of castings point to the influence of individual process parameters on the casting cooling and solidification in a mould. Figure 14 shows some faults in the casting structure caused by

a. casting with no porosity

b. casting with classified porosity

c. intensive porosity over the volume, higher pattern density and thicker coating layers, EPC process

Fig. 14. Casting faults detected by radiographic method

application of an inadequate ceramic coating in the casting process.

Utilization of ceramic coatings with different types of fillers (talc-based, cordierite-based, zircon-based, mulite-based, mica-based, chromite – based and alike) in casting decisively depends on rheology coating properties, i.e. on sedimentation suspension stability. It is necessary to carry out researches referring to optimized coating properties and to their production procedures aimed to obtain the coating properties required. Coating application in practice shows positive effects regarding high quality castings, satisfactory structure and properties, shiny and smooth castings surfaces, with no surface or volume faults whatsoever.
