Experimental and numerical investigations of platinum foil/titanium plate interfaces prepared by explosive welding

Platinum/titanium (Pt/Ti) bimetal composite is of utmost interest to the electrochemical industry for its superior functionality. Here, an improved explosive welding (EW) technology was introduced to join Pt foil and Ti sheet, and the microstructure evolution of the achieved Pt/Ti joint as well as the thermodynamic behaviors during the EW process was systematically investigated by various microscopic observations and smoothed particles hydrodynamics (SPH) simulation. It was found that the Pt/Ti EW interface was featured by a straight metallurgical reaction layer with a width of similar to 30 mu m, and its formation mechanism was related to localized melting followed by intense mechanical mixing of participant metals. In the reaction layer, both elements of Pt and Ti were detected, and the average phase was determined to be Pt0.69Fe0.31. The EBSD analyses revealed a remarkable grain structure change near the interface, such as grain orientation deflection in Pt matrix, heat-induced grain growth in Ti matrix, and the formation of extra fine nanograins in the reaction layer. The SPH simulation well captured the morphology features of the Pt/Ti interface, and quantificationally revealed the extreme thermodynamic states of high heat of similar to 2000 K, high pressure of similar to 5 GPa, and large strain of similar to 3 during the EW process. Finally, the nanoindentation results revealed inhomogenous mechanical behaviors near the bonding interface.

Automated summary

In this study, the microstructure evolution and thermodynamic behaviors of platinum/titanium (Pt/Ti) bimetal composite were systematically investigated during the explosive welding (EW) process. The results revealed the formation of a straight metallurgical reaction layer at the Pt/Ti interface, which was attributed to localized melting and intense mechanical mixing. Furthermore, changes in grain structure near the interface and extreme thermodynamic states during the process were quantitatively analyzed using smoothed particles hydrodynamics (SPH) simulation.