Numerical Simulation Of Temperature Field In Laser Deposition Of Graphite Copper Functionally Gradient Materials With Convection

In this paper, the pantograph slide plate with graphite copper functionally graded composite as the research object, the application of ANSYS / FLOTRAN module of C/Cu functionally gradient composite laser deposition process in the temperature field and flow field, of convection and materials with gradient structure influence on the temperature field,the establishment of the temperature field and the mathematical model of the flow field, and the successful implementation of the module with the temperature field and flow field of two-phase coupling. According to the thermal analysis theory and fluid mechanics analysis to determine the laser deposition temperature and convective boundary conditions; the driving force of the convection in the weld pool; by applying tension temperature coefficient in free gas-liquid interface is successfully simulated the Marangoni convection; according to the unified equation, with "solid liquid with a method to realize the simulation of solid-liquid interface, the continuity of moving. The results obtained are as follows:The fluid flows from the center to the periphery, and the flow rate increases gradually. At the edge of the weld pool, the flow velocity is maximum, and flows at the bottom of the pool to the bottom of the pool to form the circulation. The temperature field distribution is oval, the center temperature is high, the temperature is low, and the center temperature gradient is larger than the surrounding temperature gradient, the temperature gradient in front of the melting pool is greater than that of the rear temperature gradient of the molten pool.With the increase of deposition layers, the content of graphite from the bottom layer to the top layer increases gradually, and the gradient distribution. In the convection, the temperature field distribution of the bottom layer to the top layer is unchanged, but the temperature rise is gradually increasing, the volume of the molten pool increases, and the remelting rate increases. The gradient composite material with low graphite content is larger than that of the homogeneous composite material, which has a larger remelting rate, higher graphite content and a smaller remelting rate.Increasing the laser power, molten pool increases, temperature rise of the poles increase,velocity in the molten pool is also increased; spot radius increases, pool size will reduce,temperature rise pole decreases, velocity also decreases; with the increase of the scanning speed, molten pool will reduce, extreme temperature decreases and the flow rate decreases.