Functionally Graded Copper – Steel Using Laser Engineered Net Shaping ? Process

摘要

Laser Engineered Net Shaping? (LENS?) is an emerging Solid Freeform Fabricationrn(SFF) process capable of producing fully dense metallic parts with complex shapes directly fromrna computer-aided drawing (CAD) without the need for molding or tooling. The LENS? processrnalso shows promise in producing components with graded compositions. One potentialrnapplication is the production of steel – copper die casting materials. Copper is currently beingrnconsidered for deposition on dies made out of steel to enhance thermal management. However,rndifficulties can occur at the Fe-Cu interface, such as, solidification cracking, formation ofrnundesirable phases, and differences in coefficient of thermal expansion. The current researchrngoal is to develop LENS? processing parameters to optimize the deposition of functionallyrngraded steel - Copper alloys. Dilution control experiments were carried out to determine therncracking susceptibility of Steel - Cu alloys of varying compositions. The resultingrnmicrostructures were characterized by various microscopy techniques. The influence ofrncomposition on the resultant cracking susceptibility and microstructure will be discussed. Thisrninformation is useful for successful deposition of crack-free copper layers onto steel for dierncasting applications.