Transcript Slide 1
E-Foundry Project © Prof. B. Ravi, I.I.T. Bombay Project Name Student Name: Degree, Year: Branch: Institute: Part Model © Prof. B. Ravi, I.I.T. Bombay 140 140 80 40 70 80 40 20 20 60 40 80 Part Metal: Cast Iron Mold Material: Sand Part Simulation (without feeder) Hottest Region © Prof. B. Ravi, I.I.T. Bombay Feeder Design © Prof. B. Ravi, I.I.T. Bombay Diameter of Feeder = D, Height of Feeder = H = 1.5D 𝑉 Modulus of Feeder = M = 𝐴 = 𝐷2 𝐻 4 𝜋𝐷2 𝜋𝐷𝐻+ 4 𝜋 = 0.375𝜋𝐷3 /1.75 𝜋𝐷2 Modulus of Hottest Region = 256000 / 25600 = 10 mm Modulus of Feeder = 1.2 x Modulus of Hottest region = 1.2 x (256000/25600) = 12 mm From the two equations for feeder modulus, Feeder Diameter D = 56 mm Modified Surface Area of the Hottest Region = Surface area of hot spot region – Area of feeder bottom = 25600 – (𝜋562 /4) = 23137 𝑚𝑚2 Modified Modulus of Hottest Region = 256000/23137 = 11.1 mm The feeder has to be redesigned for the increased modulus of the hottest region. Feeder Design © Prof. B. Ravi, I.I.T. Bombay Modified Modulus of Feeder = 1.2 x 11.1 = 13.3 Modified Feeder Diameter Modified Feeder Height = 62.2 mm = 93 mm Modulus of Feeder Neck (Connection to Part) = 1.1 x Modulus of Hottest Region = 1.1 x 11.1 = 12.2 mm Assume some height of the neck (say 10 mm). 𝐷2 𝐻 Modulus of neck = = 𝑉 𝜋 4 = 𝐴 𝜋𝐷𝐻 = D/4 Equating the two modulus values, Feeder Neck Diameter = 48.5 mm Yield = Part volume / (Part + Feeder + Neck) volume = 490867/(490867 + 282588 + 18474) = 62% Simulation with Designed Feeder © Prof. B. Ravi, I.I.T. Bombay Feeder D = 62 mm Feeder H = 93 mm Neck D = 60 mm Neck H = 10 mm Observation: Feeder is hotter than part hot spot. A small island of high temperature is still visible inside the part. Simulation with Larger Feeder © Prof. B. Ravi, I.I.T. Bombay Feeder D = 75 mm Feeder H = 112 mm Neck D = 49 mm Neck H = 10 mm Observation: Feeder is hotter than part hot spot. There are no hot spots visible inside the part. Hence feeder design is ok. Simulation with Smaller Feeder © Prof. B. Ravi, I.I.T. Bombay Feeder D = 50 mm Feeder H = 100 mm Neck D = 40 mm Neck H = 10 mm Observation: Feeder is less hot than part hot spot. This will work only if an insulated sleeve is placed around the feeder. Comparison Feeder D = 62 mm Feeder H = 93 mm Neck D = 49 mm Neck H = 10 mm © Prof. B. Ravi, I.I.T. Bombay Feeder D = 75 mm Feeder H = 112 mm Neck D = 60 mm Neck H = 10 mm Feeder D = 50 mm Feeder H = 100 mm Neck D = 40 mm Neck H = 10 mm Designed Feeder Larger Feeder Smaller Feeder Quality Small shrinkage No shrinkage Major shrinkage Yield 62% 48% 70% Remark Unacceptable Acceptable Suitable with sleeve Conclusion: Design with larger feeder is recommended, since it shows no shrinkage defect part, and there are not additional item (sleeve) costs.