336 Section 4 Nonferrous Metallurgy 15.5.1 Casting Many nonferrous metals are cast to shape, using either disposable molds of s and or clay slurry, or permanent molds of steel. One very effective casting process for alloys that melt below 1200°F (650°C) is high-pressure die casting. In the process of die casting, liquid metal is forced into a closed steel die to solidify into very precise shapes. When the die is opened at the end of the casting cycle, ejector pins push the part out of the die. The part falls into a collecting bin or is captured by a robot reaching into the opened die. This procedure is called die casting in the United States, but is referred to as pressure die casting in the rest of the world. Figure 15-16 is an example of a die cast part. Mr.1/Shutterstock.com Figure 15-16. This die cast aluminum automotive part has a small ridge of metal created from the parting line between the two halves of the die. Parting line Vacuum valve Oil-diffusion vacuum pump Mechanical vacuum pump Path of gas from furnace out through vacuum pumps Vacuum seals Vacuum seals Chamber cover Chamber seal Melted charge Electrical feed-through Induction coils Vacuum chamber Goodheart-Willcox Publisher Figure 15-15. This sketch shows a top-loading vacuum chamber (left), with an oil diffusion (high-vacuum) pump next to the vacuum chamber and a mechanical pump supporting the high-vacuum pump. The path of gas flow from the chamber to the outside is indicated. PRACTICAL METALLURGY PRACTICAL METALLURGY (Continued) Copyright Goodheart-Willcox Co., Inc.