Faculty of Mechanical Engineering, Semnan University, Semnan, Iran
10.24200/sci.2026.68088.10973
Abstract
In this study, slight hydroforming is introduced as a localized, low-pressure deformation technique for joining double-walled tubes, where controlled radial deformation rather than full tube forming produces a mechanically interlocked ST52/GGG70 interface. A Box–Behnken response surface methodology (RSM) was employed to evaluate the effects of applied forming load (expressed as equivalent internal pressure), forming temperature (25–75 °C), and Nano-Al₂O₃ concentration (0–10 wt%) on the greatest diameter reduction (D1). The analysis revealed that the applied forming load contributed 62.4% of the total effect on D1, followed by temperature (23.1%) and nanofluid content (14.5%). The developed quadratic model exhibited excellent predictive capability (R² = 0.9874), and the optimal parameters (≈520 MPa, 73 °C, and 5.6 wt% Nano-Al₂O₃) resulted in a maximum diameter reduction of approximately 14.2%, consistent with the model prediction. Microscopy of specimens produced under optimized conditions revealed a wavy interfacial morphology with an average waviness amplitude of 18–25 µm, accompanied by a thin and discontinuous 3–6 µm intermetallic layer. This interfacial configuration effectively disrupts crack propagation paths and enhances joint integrity. Overall, the results demonstrate that optimized slight hydroforming enables the formation of a crack-resistant, mechanically interlocked interface, confirming its potential as an efficient and controllable joining technique for multi-material tubular structures.
Mansourian, R. and Mahmoodi, M. (2026). Optimization and Interfacial Microstructural Mechanisms of Double-Walled ST52/GGG70 Tube Joining via Slight Hydroforming. Scientia Iranica, (), -. doi: 10.24200/sci.2026.68088.10973
MLA
Mansourian, R. , and Mahmoodi, M. . "Optimization and Interfacial Microstructural Mechanisms of Double-Walled ST52/GGG70 Tube Joining via Slight Hydroforming", Scientia Iranica, , , 2026, -. doi: 10.24200/sci.2026.68088.10973
HARVARD
Mansourian, R., Mahmoodi, M. (2026). 'Optimization and Interfacial Microstructural Mechanisms of Double-Walled ST52/GGG70 Tube Joining via Slight Hydroforming', Scientia Iranica, (), pp. -. doi: 10.24200/sci.2026.68088.10973
CHICAGO
R. Mansourian and M. Mahmoodi, "Optimization and Interfacial Microstructural Mechanisms of Double-Walled ST52/GGG70 Tube Joining via Slight Hydroforming," Scientia Iranica, (2026): -, doi: 10.24200/sci.2026.68088.10973
VANCOUVER
Mansourian, R., Mahmoodi, M. Optimization and Interfacial Microstructural Mechanisms of Double-Walled ST52/GGG70 Tube Joining via Slight Hydroforming. Scientia Iranica, 2026; (): -. doi: 10.24200/sci.2026.68088.10973
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