The implication and evaluation of geometrical imperfections on manufactured surfaces

Classification of Visual Smoothness Standards Using Multi-Scale Areal Texture Parameters and Low-Magnification Coherence Scanning Interferometry

“…Some examples of where surface texture affects functional performance include wettability [1-3], reflectance [4,5], corrosion resistance [6,7], fatigue [7,8], and heat exchange [9,10]. While the surface aesthetic (visual and tactile) includes human perception and thus encroaches on the psychophysics domain [11][12][13][14], the topographical amplitudes and spatial relationships between different features on the surface, along with other traits such as color, thermal conductivity, and modulus, affect how the surface is perceived and valued [12,13,[15][16][17][18]. Central to understanding how surface texture affects functionality and aesthetics is to isolate metrics capable of quantifying relevant surface topographies at the appropriate length scales.…”

“…While surfaces can be easily measured in digital environments, merely assigning a numerical assessment to a surface that does not correlate with its intended function provides incomplete and potentially misleading information. Additionally, while visual comparisons to defined standards are utilized in many instances, especially regarding aesthetics, human visual inspection (HVI) processes are inherently subjective, as discussed in [11]. There is a strong desire to replace HVI with automated systems and a longstanding goal of definitively linking functionality to surface topographies.…”

“…Datasets from these systems can provide a wealth of geometrical topographical data with the scale of resolvable features dependent on system-limiting factors, tip radii for tactile measurements, and numerical aperture considerations for optical systems [31]. While the wealth of the available data is advantageous, effectively processing the data to give useful metrics still poses challenges [11,21]. Statistical parameters used to describe surfaces within the manufacturing community include height, spatial, hybrid, functional, and other parameters detailed in the ISO 25178-2 standard [32].…”