Metal Casting By Tanner Powell

Overview of Casting  Net or near net  One of the most utilized production methods  Many different types of casting named for mold types

The Function of Casting  To control the size, shape, composition, and crystalline arrangement of metal products in order to achieve the desired functionality. Iron, carbon, tungsten, vanadium, cobalt, chromium, sulfur alloy know as a Micro-Melt Maxamet Alloy

Temperature Control  Casting methods include ways to heat and cool specific areas of the mold at different rates.  Purpose of temperature control is to regulate filling and cooling rates.  A number of casting defects are caused by fast cooling rates  Grain size is also related to cooling rate. Faster to cooling rate. Faster rates yield larger grain sizes.  Larger grain sizes usually result in lower densities.

Heat Treatments  Different methods of hardening can be implemented to exploit the effects of cooling rate on grain structure.  Annealing is one most common method where a metal piece is heated to crystallization temperature. At which time crystal structures are allowed to reorient themselves. Depending on the cooling rate, the crystals may form any number of arrangements and sizes.  Grain structure has very noticeable effects many different properties of the final product.  Not only harness, ductility, and density, but also conductivity, magnetism and reactivity are effected.

References  Second Page Image html  Third Page Image industrialcasting/  Annealing of Casting; steel.com/Articles/Art16.htm  Last figure; mat1b/courseA/lecture3-5.pdf