This page contains a Flash digital edition of a book.
Fig. 2. Eagle Alloy’s marketing department used this one-page document to sell the results of a solidification-only simulation to a customer.


with a one-page document showing evaluation results for the proposed new design (Fig. 2).


about 30% scrap on valve bodies from both domestic and offshore casting suppliers. The part suffered from poor casting design, which included sharp fillets, uneven section transitions and counter bores in flange faces. Eagle Alloy redesigned the casting using


3


Validating Design and Casting Methods


A customer was experiencing


good casting engineering practice and further refined the part using solidifica- tion simulation (Fig. 3). The redesign was subjected to a solidification-only simulation to determine hot spots and feeding modulus. First, the initial gating from the first run was calculated, and simulations were run without casting changes. The customer then reviewed the fallout data it had compiled and verified the defects seen in the simu- lation were what they were seeing on actual parts. It became apparent the part needed feed pads.


Eagle Alloy’s engineers evaluated


the flange bolt pattern and washers to determine the size of pads that could remain on the casting. The feed pads were designed not to interfere with the flange bolt pattern, and simulations were run to verify the layout. The results were encouraging, so a prototype pat- tern and samples were made. X-rays of a cut-up sample revealed zero defects. Samples have been machined with no evidence of porosity and are undergo- ing additional testing.


tially designed as a threaded tube with two handles attached via welding was redesigned as a one-piece casting with the addition of a cast-in logo. In the field, the parts are used to couple hydraulic hoses. Because they are pressure vessels, they must pass a level II x-ray. While a seemingly simple part, the


4


Fig. 3. Eagle Alloy redesigned this valve body to alleviate the 30% scrap the customer was experiencing. The customer was encouraged about the redesign through the use of this solidification-only simulation.


MODERN CASTING / February 2011


design was complicated by a number of factors. First, five part sizes required the same design, and the quoted number of castings in a single mold for each


41


Aiding Conversion From Other Processes


A hydraulic coupling part ini-


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