Bonding strength evaluation of explosive welding joint of tungsten to ferritic steel using ultra-small testing technologies

The interface bonding strength of thinly coated materials is difficult to be measured accurately owing the size limitations coating layer. In this study, interfaces an underwater explosive welded tungsten foil on ferritic steel was investigated by deep-notch-type micro-tensile tests and microscopic double-notch shear (DNS) compression tests. were carried out using a focused ion beam (FIB) tensile system. results showed that region near larger than but weaker foil. micro-DNS conducted in both regions. obtained exhibited strong dependence as follows: smaller size, higher strength. Although specimens with large gauge section area similar DNS specimens, specimen approximately 1 μm² strengths (∼4.8 GPa) (3.2 GPa). Observations microstructure fracture surface indicated corresponded between welding.