Abstract: In many metal forming applications, especially in micro cold forming, the tools are loaded differently in various functional areas. Tailored material properties are therefore required. To meet this requirement, different tool steels can be applied in the specific regions of the tools, with a good bonding in between. This kind of composite materials can be produced by spray forming process. Moreover, the different tool steels in the composite tools may require different heat treatment conditions to achieve optimal material properties. For this purpose, a selective heat treatment based on middle frequency induction heating has been developed to simultaneously austenitize the tool steels at different temperatures. The process results in fine and homogeneous microstructures in both tool steels, with a gradual transition of chemical and physical properties in between. Microstructures and properties of the composite materials are clearly correlated with their austenitization conditions during induction heating.
Authors: Chengsong Cui, Alwin Schulz, and Dawid Nadolski
Keywords: Composite Tool Steels, Spray Forming, Heat Treatment