Development of a Digital Standard to Specify Surface Requirements of Cast Metal Surfaces
Communication of specifications between a customer and a manufacturer is important for meeting form, fit, and functional requirements of any part. Current standards for the requirements of cast metal surfaces use qualitative methods, including comparator plates and images of surfaces, to specify the surface quality allowing ample room for variation in interpretation of the standard. The length scale of existing contact surface measurements is too small for most casting surfaces. This paper covered a proposed digital standard for specifying cast metal surfaces. The proposed digital standard used point cloud data of a cast surface, likely attained using a non-contact capture method, in order to identify roughness properties and anomalies caused by the casting process. Unlike current qualitative methods, this standard does not specify the potential causes of surface issues, such as porosity or inclusions. This standard was developed in order to reduce measurement variation and eliminate confusion between the customer and manufacturer. Assigning quantitative criterion to the surface allows the customer to specify exactly what is needed as opposed to limiting them to a subjective comparator or image to base their requirements. Additionally, this quantitative method could be used to verify visual inspection results among the inspectors within a production facility to reduce their measurement error and improve productivity.
This is an article from ASTM Materials Performance and Characterization 6 (2017): doi:10.1520/MPC20160014. Posted with permission.