Additive Manufacturing of Directionally Heat Conductive Objects

Purpose: Directionally Heat Conductive (DHC) objects are also known as thermal cables. DHC objects used in cooling solid state devices as large heat sinks. This paper presents Additive manufacturing (AM) as a new method for realization of DHC objects. AM can produce DHC objects accurately, rapidly and economically. Design/Methodology/Approach: It is very hard to realize DHC objects through conventional manufacturing. The authors describe the realization of metallic DHC objects using their AM process called Hybrid Layered Manufacturing (HLM). HLM, which uses GMAW deposition, can, in principle, produce DHC out of any metal for which welding wire is available. . Differential conductivity in HLM is achieved by appropriately distributing the air gaps among the beads. The air gap distribution depends on the layer thickness and step over increment. Findings: The authors have demonstrated the ability of HLM to produce DHC objects for Al alloy 4043. The thermal conductivity achieved on two orthogonal directions was 100.496 and 129.740 W m-1 K-1 as against 163 W m-1 K-1 for solid metal. These are significant variations. Research Limitations/Implications: HLM realize near net shape of DHC objects, further post processing namely machining is required. Originality Value: AM Specifically HLM for realization of DHC objects