3D Analysis of Casting Surface Characterization Based on the Variogram Roughness Method

Abstract

Casting surface specifications are commonly inspected via visual inspection. Since visual inspection is subjective, the results are not very reliable. Objective methods that could replace visual inspection for simple surface patches, and thus increased the reliability of the inspection process has been introduced. This paper continued the work on the variogram roughness method and adopted the method to produce reliable results for 3D scans of complete castings. This enables foundries to utilize existing 3D scanners used for dimensional inspection for surface roughness inspection of their castings and potentially using the same dataset for both needs. This paper will describe the function of this method and how it was adopted to whole castings. Tests will also be performed to validate the method in 3D. To accomplish this, the results from the validated method for flat surfaces were used to determine the surface roughness of flat surface patches on a cube. The cubes were created from plastic copies of the SCRATA comparators. Overall, comparable results to the previous method were possible. The highest deviations were seen for rough surfaces. Further, with its local roughness determination, the method can also be used as an input for automated surface finishing.