Numerical investigation on heat transfer and thermal stress developed during the microlaser joining of glass sheets

Abstract This work performs a numerical investigation on the transport phenomena and subsequent development of thermal stress during the joining of two glass sheets in a lap configuration with an intermediate solder layer surrounding the edges of glass sheets under a microlaser beam. The energy equation with appropriate boundary conditions is used to simulate the joining process. The governing equation is discretized based on the finite difference method using the Crank–Nicolson scheme and solved by developing a 3D code on the FORTRAN platform. Following the code’s validation, this study predicts the distribution of temperature and the corresponding development of thermal stress during the joining of the glass sheets while considering the movement of the microlaser beam. A parametric study is also conducted under different laser powers, laser beam diameters and travelling velocities. The joining of the glass sheets without bending is possible under a power of 7.5 W using a microlaser with a beam diameter greater than 380 µ m and a travelling velocity greater than 1 mm s −1 . This investigation also identifies the operating regimes at different laser beam radii and powers, which is the novelty of this research.