Negative thermal expansion in Ti2O3-SiC composites induced by microstructural effect

Regulating and reducing the thermal expansion of materials has long been a challenge. In this study, a composite with negative thermal expansion (NTE) has been obtained by combining two intrinsically positive thermal expansion (PTE) materials—Ti 2 O 3 and SiC via microstructural effect. We have realized the successful retention and amplification of the microstructural effect of Ti 2 O 3 within the composite. The synchrotron X-ray computed tomography and mercury injection porosimeter reveals that the composite exhibits a unique pore distribution and enhanced porosity, enabling NTE properties that exceed theoretical predictions. This work provides a novel approach to transforming the intrinsic thermal expansion behavior of materials via microstructural effect, paving the way for innovative applications of NTE materials in precision engineering.