Bronze infiltration

Metals Stainless steel powder (comparable X2CrNiMo 1.4404) and a mold steel (X42Crl3 comparable 1.2083) that can be brought to a hardness of 54 HRC after the oven process are available. Due to the bronze infiltration, the mechanical-techno-logical properties of the materials are generally lower than that of the semifinished products but the thermal conductivity is higher. 

Direct Tooling Mold inserts, which may also contain internal cooling channels, are made with 3D printing processes. The bronze infiltration leads to a higher thermal conductivity, which may be advantageous if the tendency to worse mechanical-technological properties is accepted. 

For Direct Tooling, 3D printing allows making tool inserts that may contain interior channels. Infiltration with bronze increases the thermal conductivity that improves the cycle time if the mechanical properties can be accepted. 

D printing process can process aii materiais, which are avaiiabie as powders. They aiiow the production of internai cavities. The components do not require support structures. The metai processes are multistage processes and run at room temperature. They require a subsequent oven process and an infiltration with bronze. The relatively rough surface is a disadvantage of the process. Rework will be very complex especially for metal components and also affects the accuracy. 

Materials successfully applied as a contact surface include boron nitride coated graphite, alumina, and quartz. Each possesses a smooth surface that does not react with the metal sample in a high temperature environment. Contact pressure was applied by either thermally compressing the stack or applying a weight. To compress a stack by thermal means, an inconel rod was placed at either end of the stack between the end sample and crucible wall. When the inconel rod lengthens due to thermal expansion, a compressive force is applied to the stack. This can be seen in Figure 3 where a setup is shown post-infiltration. Note the lateral face application of the contact surfaces and the placement of the stilts into the pool of bronze. 

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