Thermomechanical stress distribution and fracture behavior of cracked Cu/Al2O3 bimaterials with functionally graded interlayers

Liamani S., Sahli A., Belfennache D., Reffas S. A., Ghebouli M. A., Fatmi M., ...Daha Fazla

MATERIALS & DESIGN, cilt.269, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 269
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1016/j.matdes.2026.116844
  • Dergi Adı: MATERIALS & DESIGN
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chimica, Compendex, INSPEC, Directory of Open Access Journals, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
  • Recep Tayyip Erdoğan Üniversitesi Adresli: Evet

Özet

Metal-ceramic bimaterials are widely used in high-temperature and structural applications because they combine the toughness of metals with the thermal resistance of ceramics. However, differences in elastic modulus and coefficient of thermal expansion (CTE) create significant residual stresses at the interface, which can lead to cracking and failure. This study investigates the thermomechanical behavior of a cracked copper/ alumina (Cu/Al2O3) system using a three-dimensional finite element model. Functionally graded material (FGM) interlayers with linear, logarithmic, and exponential property variations are analyzed. Results show that thermal loading plays a dominant role in stress development, significantly increasing stress concentrations near the interface due to material mismatch. As temperature rises, both residual stresses and the mode-I stress intensity factor (KI) increase, indicating a higher risk of crack propagation. Cracks located close to the interface experience the greatest amplification in KI, highlighting strong interaction effects. The inclusion of an FGM interlayer effectively reduces stress concentration and smooths stress distribution across the interface. Among the investigated gradation profiles, the logarithmic variation provides the most favorable overall redistribution of von Mises stress, whereas the gradation law producing the lowest mode-I stress intensity factor depends on crack length and crack-interface distance.