Research On Deposition Growth Mechanism And Parameter Optimization Of Double-nozzle Spray Forming

With the advantages of rapid solidification, semi-solid forming, near-net characteristics, the sprayforming technology get increasing applications in the field of preparation for high-performance metaland alloy materials. This technology mainly has two processes, atomization of the molten alloy anddeposition of droplets onto the movable substrate. Around two main objectives of normativemorphology and uniform deposition, the spray deposition process of double-nozzle is analyzed in thispaper. And the research of this paper includes theoretical researches and simulations around theuniformity in the radial direction, deposition growth mechanism and the detection of morphologyparameters, thus to provide a theoretical basis for the actual production of billets.The scanning mode of nozzle and its trajectory have important influences on the distribution ofmetal deposited on the substrate. On the basis of billet uniform deposition affecting factors, phasedvariable scanning method driving by cam is proposed. Then create six-stage variable scanning motionmodel of the cone. And the displacements and speed of pendulum and putter, the outline of the camare both designed. Also deposition trajectory model is created in this paper. The effects of processparameters on the trajectory and its coupling conditions are analyzed. Then make a simulation basedon the deposition model to provide theoretical bases for selecting the frequency of nozzle and thespeed of substrate.This paper researches into deposition growth mechanism and then makes simulated analysis. Basedon the analysis of typical morphology of billets, self-regulating phenomenon is put forward first time.Self-regulating model is established on the basis of quality tiling method. Using this model, theconditions of self-regulating convergence is researched, and how to solve parameters’ critical range isgiven. The influences of nozzle flow rate, installation eccentricity, spray height, initial tilt angle andscanning amplitude on morphology are analyzed. All of these researches provide a theoretical basisand simulation method for parameter optimization options.Online detection technology of billets morphology (including the diameter of billet depositionsurface, spray height, and the height of growing billet) is researched. The method of “multi-pointmeasuring and weighted average” is detailed analyzed, and this method can reduce measuring error.Based on this, the number of detection point is optimized. At the same time, a controlling method ofsensor servo used to detect the diameter of deposition surface is proposed. The researches laid thefoundation for real-time monitoring and further controlling during spray forming. Based on the theories and simulations of deposition uniformity, self-regulating mechanism andparameter optimization, the verified experiments are done respectively. And the results of experimentsindicate the correctness of the research route, method and conclusions.