TY - JOUR

T1 - An X-ray Microscopy Study of the Microstructural Effects on Thermal Conductivity in Cast Aluminum-Copper Compounds

AU - Fromm, Andreas Christopher

AU - Kahra, Christoph

AU - Selmanovic, Armin

AU - Maier, Hans Jürgen

AU - Klose, Christian

N1 - Funding Information: This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—Project-ID 394563137—SFB 1368.

PY - 2023/3/29

Y1 - 2023/3/29

N2 - A metallurgical joint between aluminum and copper established by compound casting provides for high thermal conductivity, which is required for lightweight cooling solutions in applications such as high-power light-emitting diodes or computer processors. If casting is employed in a silane-doped inert gas atmosphere whose oxygen partial pressure is adequate to extreme high vacuum, reoxidation of the active surfaces of aluminum and copper is prevented, and thus a metallurgical bond can be created directly between aluminum and copper. With this approach, thermal conductivities as high as 88.3 W/m·K were realized. In addition, X-ray microscopy was used to shed light on the microstructure–thermal property relationship. It is demonstrated that both porosity and non-bonded areas have a substantial impact on the thermophysical properties of the compound zone. Based on the data obtained, casting parameters can be developed that provide for defect-free bonding zones and optimal heat transfer between the joining partners.

AB - A metallurgical joint between aluminum and copper established by compound casting provides for high thermal conductivity, which is required for lightweight cooling solutions in applications such as high-power light-emitting diodes or computer processors. If casting is employed in a silane-doped inert gas atmosphere whose oxygen partial pressure is adequate to extreme high vacuum, reoxidation of the active surfaces of aluminum and copper is prevented, and thus a metallurgical bond can be created directly between aluminum and copper. With this approach, thermal conductivities as high as 88.3 W/m·K were realized. In addition, X-ray microscopy was used to shed light on the microstructure–thermal property relationship. It is demonstrated that both porosity and non-bonded areas have a substantial impact on the thermophysical properties of the compound zone. Based on the data obtained, casting parameters can be developed that provide for defect-free bonding zones and optimal heat transfer between the joining partners.

KW - aluminum-copper compounds

KW - compound casting

KW - Kirkendall effect

KW - microstructure

KW - porosity

KW - silane

KW - thermal conductivity

KW - volumetric characterization

KW - X-ray microscopy

UR - http://www.scopus.com/inward/record.url?scp=85156130568&partnerID=8YFLogxK

U2 - 10.3390/met13040671

DO - 10.3390/met13040671

M3 - Article

AN - SCOPUS:85156130568

VL - 13

JO - Metals

JF - Metals

SN - 2075-4701

IS - 4

M1 - 671

ER -