Using sol–gel component as additive to foundry coatings to improve casting quality

A non-contact 3D method to characterize the surface roughness of castings

“…Due to these drawbacks, contact-type instruments are not suitable for high-speed automated inspection according to Tien et al (2009). Again, Nwaogu et al (2011Nwaogu et al ( , 2012 observed that contact-type instruments are difficult to work with on sand cast surfaces because of high surface roughness encountered and material pick-up which depended on the hardness of the surface measured. Hence, the application of a non-contact and non-destructive method for the characterization of the surface roughness of castings.…”

“…It was reported in the standard BS EN1370 (1997 that the surface roughness of castings is influenced by the manufacturing process (expendable mould process, permanent mould process, etc.). In another investigation, Nwaogu et al (2012) showed that the moulding materials used (sand, binder, coatings, thermal properties, etc. ) also affect the casting surface quality.…”

Experimental Evaluation of Ceramic Coatings for Die Protection in Low-Pressure Die-Casting Process

“…Ten measurements were made in different positions above the coating surface, and the mean values were obtained for each sample. The roughness of the coatings can be a critical factor for the LPDC process and is usually a compromise between insulation requirements for an adequate filling process for and the surface finishing requirements of the cast parts [20,32,33]. The mean roughness values of the different coatings obtained by confocal microscopy is presented in Figure 6.…”

“…LPDC die coating failures usually come from the loss of adherence or excessive wear originated in the successive filling processes, which requires stopping production for the reapplication of the coating. Even though chemical and physical parameters of refractory foundry coatings are known to specialists in the field [27][28][29][30], there is a lack of knowledge regarding the relationship of particle size of the refractory filler and the final appearance and erosion resistance of the layer deposited on the mould [20,[31][32][33]. Several authors have claim for the need of a bridge between the foundry coating characteristics and tribological science in order to prove that an improved erosion resistance coating will help to produce better quality cast parts [20,31,32,34,35].…”