The textures are defined by the removal of cylindrical holes; for
the asymmetric-depth-profile textures the cylinder is angled with
respect to the surface normal. The textures are millimetric in size
(Fig. 2) to enable good dimensional control achieved by machining
with an end mill with diameter 1/8” to cut out a cylindrical shape
with radius R¼3 mm. The angle β was achieved by tilting the
substrate with respect to the end mill axis of rotation. A solid
model of an asymmetric texture is shown in Fig. 3 showing isometric
and profile views. The parameters 2R, β, and δ define the
texture as shown in Fig. 3C. The asymmetric textures are oriented
at an angle β with the face of the cylinder having a single point
located at the surface. Fig. 4 shows representative measured centerline
profiles of each surface texture tested, and Table 1 gives the
as-built geometric parameters for each texture. The centerline
profiles were measured using a laser displacement meter manufactured
by Keyence, the geometric parameters were measured
using calipers, and the surface roughness was measured using a
KLA Tencor P-11 stylus profilometer where the surface roughness
was obtained in the non-textured region of the textured plate. The
geometric parameters (Fig. 2D schematic) relate to the 2R, β, and δ
parameters of the solid model