Soda Lime Silicate Glass-Copper Metal Joining by Controlled Heat Treatments in Air

Metal-glass joints are needed to improve efficiencies of heat collecting units used in linear parabolic sun collector systems. Soda lime silicate glass-copper metal joints were prepared at 800°C for 5, 10 and 20 min by furnace treatment in air. Cu is rapidly oxidized with heat treatment in air, reacted with glass and formed some bubbles at reaction interface. Scanning electron microscope investigation suggested copper oxide formation at copper interface, reaction between copper oxide and glass and formation of bubbles at joining interface and some microcracking for the studied glass disk on Cu disk sample profiles. ANSYS14 software simulations suggested joined glass experienced complicated and high residual stress levels due to big thermal expansion coefficient difference and bubble formation at the joining interface. The residual minimal principal stress levels were at the order of -400 MPa for joined glass at interface produced microcracking in glass starting from joined interface growing into glass layer.