FE-Based Heat Transfer Analysis of Laser Additive Manufacturing on Ti–6Al–4V Alloy

A thorough understanding of laser-based additive manufacturing process and effect of various process variables such as scanning velocity and laser beam power on melt-pool dimensions and temperature variation is a promising task in design and manufacture of an able product. The present work is focused on comprehending the thermal and melt-pool behavior of a high layer thickness five-layer laser additive manufacturing of Ti–6Al–4V alloy quantitatively. A three-dimensional (3D) nonlinear transient thermal model is developed based on a finite element procedure to simulate single- and multi-layer of Ti–6Al–4V alloy and to estimate melt-pool dimensions and thermal cycles. In this work, temperature-dependent material properties and Gaussian distributed ‘disk’ heat source model are implemented along with actual process boundary and initial conditions. Also, the influence of laser beam power and laser scanning velocity was examined with respect to melt-pool characteristics and thermal cycles. The laser scanning velocity ranges from 200 to 500 mm s−1 and laser beam power from 100 to 400 W are examined. It is observed that the temperature rises for successive layers as the laser power supply continues on consecutive layers. Also, it is obvious that with the rise in temperature, melt-pool dimensions also increase. Furthermore, the melt-pool dimensions increase as the number of deposited layers increases. Time–temperature history and melt-pool evolution in different layers with respect to laser beam power and laser scanning velocity are presented. To verify the effectiveness of the developed model, simulated results are compared with experimentally measured melt-pool profiles and dimensions. A fair agreement between experimental results and computed values is achieved.