You might want Space Bar/Common/Boundary. But the title will always be centered.
Did you want the border on the diagram in the model, or when it is exported? There is an option to add the border and diagram name to exported images? I think the name is on the top left (but stand to be corrected) - the option is in the Preferences under Diagram - Diagram Frames.
Just wondering as you mention fragments so you might be referring to saving the model as images.
That's ok - it's what the forum is for (and I've had my share of answers before).