Problem 1. Chapter 10 Pouring Calculations A mold sprue is 25 cm long, and the cross-sectional area at its base is 3.0 cm. The sprue feeds a horizontal runner leading into a mold cavity whose volume is 1700 cm. Determine: (a) velocity of the molten metal at the base of the sprue, (b) volume rate of flow, and (c) time to fill the mold. (The acceleration of gravity g = 981 cm/s) Problem 2. Chapter 11 Time to Heat the Metal to Pouring Temperature 80 kg of aluminum is to be heated to a pouring temperature of 750C. The unit melting and pouring energy of the metal = 1035 J/g. Thermal efficiency of the furnace = 65%. How much time is required to heat the metal from 25C to the pouring temperature if the electric induction furnace generates 100 kW? Problem 3. Chapter 15 Operation of a Flow-Through Sintering Furnace The recommended sintering time for a pressed part is 20 min. The sintering chamber of the flow- through furnace is 4.0 m long. The number of parts that can be placed on 1 m of conveyor belt length is 15 pc. Determine the (a) speed of the conveyor, (b) processing rate of the furnace, and (c) quantity of parts being sintered at one time. Problem 4. Chapter 15 Cost per Piece of a Powder Metallurgy Part Metal powders are blended and mixed in step 1 of a conventional press-and-sinter process in which the total quantity of PM parts to be produced is 20,000, and the total cost of the metal powders is $30,000. The amount of powders per batch in step 1 is sufficient for 350 PM parts. The cost rate of the blending and mixing equipment is $60/hr and the time to setup and run the batch in step 1 is 30.0 min. In step 2, pressing, the cycle time to powder feed, press, eject, and collect the green parts is 12.0 s/pc. Time to set up the press before production is 1.2 hr. With a production run of 20,000 pc, no refurbishing of the punch and die will be required. The cost rate of the press is $60/hr. In step 3, sintering, the flow-through furnace has a sinter processing rate of 3 pc/min, and the furnace cost rate is $66/hr. Determine the total cost per completed PM part.