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Multiscale Simulation of Crack Propagation in Impact-Welded Al4Cu9 Alloy Based on Cohesive Zone Model
Rongqing Luo1, Dingjun Xiao1, Guangzhao Pei1
1School of Environment and Resource, Southwest University of Science and Technology, Mianyang 621010, China.
Materials (Basel, Switzerland)
|November 13, 2025
Summary
This study reveals that combined defects significantly reduce fracture energy in Al4Cu9 joints. Multiscale modeling and experiments validate fracture mechanisms for improved aerospace Cu/Al welded structures.
Area of Science:
- Materials Science
- Mechanical Engineering
- Computational Modeling
Background:
- The fracture behavior of Al4Cu9 intermetallic compounds in impact-welded Cu/Al joints requires further investigation.
- Existing research lacks integrated multiscale modeling and experimental validation for these interfaces.
Purpose of the Study:
- To investigate crack propagation mechanisms in impact-welded Cu/Al joints using a combined simulation-experiment approach.
- To elucidate the multiscale fracture behavior of the Al4Cu9 interface under various defect configurations.
Main Methods:
- Integrated multiscale modeling: Molecular Dynamics (MD) simulations and Finite Element (FE) analysis (ABAQUS).
- Cohesive Zone Model (CZM) implementation for interface behavior.
- Experimental validation using Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) on annealed Cu/Al specimens.
Main Results:
- Composite defects (blunt crack + void) drastically reduce fracture energy and stress intensity factor compared to single defects.
- Defect effects on fracture are more significant than temperature effects (200-500 K).
- Experimental crack initiation sites strongly agreed with simulation predictions.
Conclusions:
- The integrated approach successfully elucidates multiscale fracture mechanisms of the Al4Cu9 interface.
- Provides a validated basis for reliability assessment and optimization of aerospace Cu/Al welded structures.
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