The heat treating process alters the alloy distribution and transforms the soft matrix into a hard matrix capable of withstanding the pressure, abrasion and impacts inherent in metal forming. Each step of the heat treating cycle is designed to perform a specific function, and, like links in a chain, the final product is only as good as its weakest component. Although it may only represent 10% or less of the cost of the tool, the heat treat process is probably the single most important factor in determining the performance of a tool. There is no such thing as an acceptable shortcut in heat treating tool steels.
The pattern is surrounded, or “invested”, into ceramic slurry that hardens into the mold. Investment casting is often referred to as “lost-wax casting” because the wax pattern is melted out of the mold after it has been formed.