Study On Process Energy Efficiency Of Laser Direct Deposition Technology Based On Shape Features

Green manufacturing has become the only way which must be passed for the development of the manufacturing industry.Reducing energy consumption and increasing resource utilization have become research hotspots in the manufacturing industry.Laser direct deposition technology is an additive manufacturing technology and has a good application prospect,but its low energy efficiency in the manufacturing process has limited its development,thus the improvement of energy efficiency for laser direct deposition process has become an urgent problem to be solved.Owing to process level energy efficiency directly affects the energy efficiency of the entire manufacturing process in laser direct deposition,studying the energy efficiency at the process level can help to improve the energy efficiency of the entire manufacturing process of laser direct deposition technology.This article focuses on the problems existing in the energy efficiency model of Multi-track Multi-layer process which was established by the research group in preliminary work.The relationship between the process parameters and the energy efficiency of Multi-track Multi-layer process was obtained through experiments.It was found that the main factors influencing the energy efficiency are the lift height and the number of deposited layers.Based on this result,the energy coefficient of energy efficiency model for Multi-track Multi-layer process was revised and the energy efficiency model was improved.According to the forming characteristics of the deposited parts in direct laser deposition,the shape features of the deposited parts are divided into linear deposition characteristics and arc deposition characteristics and the effect of different shape features on the energy efficiency during laser direct deposition was studied.A comparative experiment was conducted to compare the effects of two deposition features on the energy efficiency of laser direct deposition.It was found that there was no significant difference between the linear deposition characteristics and the arc deposition characteristics.The result demonstrated that the energy efficiency during direct laser deposition is not affected by the shape characteristics.In order to explore the synergistic relationship between energy efficiency and process performance in laser direct deposition,a collaborative experiment of energy efficiency and process performance was conducted by using energy efficiency as an optimization indicator,and a deposition part was obtained in terms of high energy efficiency indicators.It was found that the process performance of the deposited parts under the highest energy efficiency index did not meet the requirements.In laser direct deposition,remelting rate is related to process performance and energy efficiency.Therefore,the remelting rate is used as an intermediate variable to characterize the relationship between process performance and energy efficiency.A series of collaborative experiments of energy efficiency and process performance were implemented,it was found that the process performance of the deposited parts is better when the remelting rate is greater than 60%.Using 60%remelting rate as the constraint condition,the process parameters are optimized by using established energy efficiency models of laser direct deposition,and the process parameters that meet the process performance requirements and high energy efficiency are obtained.The process parameter is power 900W,scanning speed 1Omm/min,powder feeding rate 15g/min,overlap ratio 0.4,lifting 2/3H,which achieves the synergetic optimization of process performance and energy efficiency for laser direct deposition.