Threaded fasteners comes to mind. Can you say, "Bolts and nuts?"
I did some training at a fossil fuel power plant several years ago. They lined the steel stack with titanium sheets. Someone told them to weld stainless (you know, the shiny kind that doesn't rust) plate to the carbon steel and then weld the titanium sheets to the stainless steel plates with stainless electrode (again, the shiny kind, already told you once what kind). They said the first time they fired up the boilers they had 4 x 8 foot sheets of titanium shooting out the top of the stack and landing on the cars in the parking lot.
Evidently the stainless they selected wasn't the right shiny kind after all.
Best regards - Al