. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DESIGN DETAILS
Fuel Delivery Casting Succeeds With Attention to Gating
Jiten Shah, Product Development & Analysis, Naperville, Illinois CASTING PROFILE
Casting Process: Investment casting. Material: Stainless steel 316. Application: Automotive. Dimensions: 9.8 x 7.2 x 6.3 in.
A
risto-Cast Inc., Almont, Mich., produced this prototype head casting for a fuel delivery system designed to reduce fossil fuel usage. The casting was converted from a 12-piece weldment and solution an- nealed (a heat treatment method involving heating the metal followed by cooling for a uniform microstructure free of carbides). The casting
supplier used solidifi cation software to fi nd the gating and casting parameters that would produce the best results. Once the fi rst samples were cast, minor gat- ing and casting parameter changes were made. The parts were delivered to the customer in less than four weeks.
Cored holes eliminate complex 3D drilling. • A carefully designed casting confi guration allows cored features for the oil passages, which in the weldment had to be drilled and machined.
• However, as-cast cored holes are limited in size, depending on the section thickness, orienta- tion, alloy and investment pattern type being used. So, some passages may be cast solid and drilled in later.
Gating attachments ease investment pattern handling during the dipping and drying process. • All the gating attachments were designed in the casting for ease in handling the wax pattern during slurry dipping and drying, as well as pouring the molten steel into the pre-heated shell.
Thick to thin section transition aids directional solidifi cation. • The steel casting was designed such that the heavy sections fed the lighter sections, achieving directional solidifi cation for better soundness. Computer simulation is useful for such complex casting design and development.
• Solidifi cation simulation showed that the fi rst areas to solidify were the thin sections, while the last areas to solidify were the thick sections.
METAL
Jiten Shah is president of Product Development & Analysis (PDA) LLC, Naperville, Ill., and a 25-year casting design and manufacturing veteran.
20 METAL CASTING DESIGN & PURCHASING JULY/AUGUST 2010
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60