Functionally graded copper – steel using laser engineered net shaping™ process

Abstract

Laser Engineered Net Shaping (LENS) is an emerging Solid Freeform Fabrication (SFF) process capable of producing fully dense metallic parts with complex shapes directly from a computer-aided drawing (CAD) without the need for molding or tooling. The LENS process also shows promise in producing components with graded compositions. One potential application is the production of steel-copper die casting materials. Copper is currently deposited on dies made out of steel to enhance thermal management, however, difficulties can occur at the Fe-Cu interface, such as, a large solidification temperature range in the Fe-Cu system (which can cause solidification cracking), formation of undesirable phases, and differences in coefficient of thermal expansion. The current research goal is to develop LENS processing parameters to optimize the deposition of functionally graded steel-Copper alloy. Dilution control experiments were carried out to determine the cracking susceptibility of Steel-Cu alloys of varying compositions. The resulting microstructures were characterized by various microscopy techniques. The influence of composition on the resultant cracking susceptibility and microstructure will be discussed. This information is useful for successful deposition of crack-free copper layers onto steel for die casting applications.

An overview of Direct Laser Deposition for additive manufacturing; Part I: Transport phenomena, modeling and diagnostics

“…can be used to generate functionally, compositionally-graded material, such as H13 tool steel and A c c e p t e d M a n u s c r i p t copper for thermally-conductive mold dies or implants [120][121][122][123], tungsten carbide-cobalt cerment [46], compositionally-gradient titanium-chromium alloy [124,125], compositionallygradient titanium-vanadium and titanium-molybdenum alloys [126], nickel aluminides [127] and AISI 316L SS-Inconel 718 [128]. Understanding, modeling and optimizing the particle/laser interactions, prior to melt pool entry, is important for furthering DLD technology.…”

Laser direct metal deposition: theory and applications in manufacturing and maintenance

“…The technique was proposed in 1987 to develop heat-resistant coatings, but material combinations, such as copper and nickel (Shin et al, 2003), copper and tool steel (Noecker II and DuPont, 2002), and stainless steel and satellite (Iakovlev et al, 2002) have since been demonstrated. Mazumder et al (1999bMazumder et al ( , 2002 have proposed the concept of using multiple material LDMD to control part manufacture to the level of 'designed' microstructures and have described the development of a complete methodology for the design, representation and fabrication of graded materials (Mazumder, 2003).…”

Multi-Material Freeform Fabrication of Active Systems

“…Together, these two properties imply that SFF processes are subject to very different constraints than traditional material removal-based manufacturing. As has been demonstrated with various (but no single) SFF system, nearly arbitrary product geometries are achievable [1] and parts can be made without hard tooling, raw materials may be more efficiently used than in subtractive processes, mating parts and fully assembled mechanisms can be fabricated in a single step [2], exogenously produced components, such as integrated circuits, can be "dropped in" during fabrication [3], and multiple materials (including, electronic- [4], chemical-, and bio-materials [5][6][7] and even living tissues [8,9]) can be combined to create graded material properties [10][11][12][13] and even complete functional devices [14][15][16]. Furthermore, one or more SFF processes can typically be implemented within a single small workcell [3,14] -compacting enormously what might have once required many separate machines.…”