R_Bibb_Medical_Modelling_The_Application_of_Adv.pdf

Second experiment
Case studies 237
6.88 316L stainless steel RPD framework fi tted to patient cast.
The same RPD framework design was manufactured using cobalt-chrome
alloy using a layer thickness of 0.075 mm (Sandvik Osprey Ltd). The principal
reason for attempting the design in cobalt-chrome was for direct
comparison with traditionally made RPD frameworks, which are typically
cast from the same material. Like the previous material, the SLM TM machine
manufacturers have shown cobalt-chrome to be suitable for processing by
SLM TM . As before, the laser had a maximum scan speed of 300 mm/s with
a beam diameter 0.150–0.200 mm. The material used was cobalt-chrome
spherical powder with a maximum particle size of 0.045 mm (particle size
range 0.005–0.045 mm) and a mean particle size of approximately 0.030 mm.
The part proved successful and produced a complete cobalt-chrome RPD
framework, shown in Fig. 6.89.
Step 4: fi nishing
Supporting structures were removed with a Dremel ® hand-held power tool
(Robert Bosch Tool Corporation, 4915 21st Street, Racine, WI 53406,
USA) using a reinforced cutting wheel (Dremel, Reinforced Cutting Disc,