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Wide Temperature Zero Thermal Expansion in Al Matrix Composites with High Thermal Conductivity
Jinrui Qian1,2, Feixiang Long3, Yiqing Liu3
1State Key Laboratory for Advanced Metals and Materials, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing, China.
Summary
Engineered aluminum composites with negative thermal expansion (NTE) materials achieve wide-range zero thermal expansion (ZTE). This breakthrough overcomes narrow operational windows, enabling high-precision aerospace applications.
Area of Science:
- Materials Science
- Nanotechnology
- Composite Materials
Background:
- Lightweight aluminum (Al) composites with negative thermal expansion (NTE) materials offer low temperature sensitivity for precision and aerospace uses.
- Existing NTE reinforcements have narrow operational windows, hindering wide-range zero thermal expansion (ZTE) in composites.
Purpose of the Study:
- To address the narrow operational window limitation of NTE materials in Al composites.
- To achieve wide-range ZTE behavior in Zn1.6Mg0.4P2O7/Al composites through strain engineering.
Main Methods:
- Utilized a strain engineering strategy on Zn1.6Mg0.4P2O7/Al composites.
- Applied compressive strain from the Al matrix to broaden the NTE response of Zn1.6Mg0.4P2O7.
- Characterized the material using in situ neutron powder diffraction, Raman spectroscopy, and X-ray diffraction.
Main Results:
- Zn1.6Mg0.4P2O7 exhibited a broad, uniform NTE response over 80°C under Al matrix-induced strain, unlike its inherent 20°C window.
- A composite with 35 vol.% Zn1.6Mg0.4P2O7 achieved high-performance ZTE (0.90 ppm/°C) from 25-80°C.
- The ZTE material demonstrated excellent thermal conductivity (80.9 W·m-1·K-1), surpassing Invar alloy.
Conclusions:
- Strain engineering effectively broadens the NTE response of Zn1.6Mg0.4P2O7, enabling wide-range ZTE in Al composites.
- Strain-driven structural transformations are responsible for the gradual volume shrinkage in the NTE phase.
- This approach offers a practical method for enhancing NTE material performance for specialized applications.
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