Techniques for forming cast parts for medical devices suitable for contact with internal regions of patients are described herein. Such parts can be small in scale (e.g., having a major axis less than 0.3 inches, and/or a minor axis less than about 0.08 inches), and can be formed from metals that have a high melting point and high reactivity with environmental components or mold surfaces, such as stainless steel and titanium alloys. Such techniques can include injecting molten metal into the sprue of a mold tree such that the side runners are backfilled after the molten metal impacts a closed end of the sprue. Side runners can be oriented in particular directions and positions to promote backfilling. As well, flask temperatures and the use of surfactants can also promote cast part formation, hindering the formation of surface defects.

Title
Cast parts with improved surface properties and methods for their production
Application Number
11/949262
Publication Number
20080121365
Application Date
December 3, 2007
Publication Date
May 29, 2008
Inventor
Samardh Onukuri
Cincinnati
OH, US
Brian S DeForce
Port Matilda
PA, US
Donald F Heaney
Philipsburg
PA, US
Tracy J Potter
Philipsburg
PA, US
William A Crawford
Cincinnati
OH, US
Agent
Nutter Mcclennen & Fish
MA, US
Assignee
Ethicon Endo Surgery
OH, US
IPC
B22C 09/00
B22D 13/00
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