Abstract: The invention pertains to a flat product in the form of a wall for a heat exchanger that is operated with cooling mediums in the form of corrosive liquids that contain biological organisms. In order to protect the wall of the heat exchanger against corrosion on the side that comes in contact with the cooling medium and to prevent biological organisms from settling down on the heat exchanger wall, the wall consists of a titanium or titanium alloy layer and a copper/titanium alloy layer that is integrally connected to the titanium or titanium alloy layer by means of an intermediate alloy layer.

Abstract: The invention relates to a roll-bonded titanium sheet (6), a shaped component manufactured therefrom (10) and a method for manufacturing the titanium sheet (6) and the shaped component (10). In order to achieve a high-temperature-resistant shaped component (10), a titanium sheet (2) is roll-bonded at least on one side with aluminium foil (4) whose thickness (d) is small compared with the thickness (D) of the titanium sheet (2). As a result of heat treatment of the roll-bonded titanium sheet (6), the aluminium and titanium from the adjoining region are converted to an aluminium-titanium alloy. The outer titanium-aluminium-alloy layer of the titanium sheet (6) thus formed is converted by contact with oxygen into a titanium-aluminium-mixed oxide layer which gives the titanium sheet (6) good corrosion protection. The forming of the shaped component (10) preferably takes place before the heat treatment for alloy formation because the roll-bonded titanium sheet (6) is then still slightly deformable.