Research On Parameter Optimization Of Selective Laser Melting Building And Design Of Digital Twin System

With the rapid development and widespread popularization of advanced information technology,the traditional manufacturing industry is shifting towards a more intelligent direction.The basis of intelligent manufacturing is the interconnection between physical space and virtual space.Digital twins are the best way to achieve their integration.In many manufacturing technologies,selective laser melting(SLM)of superalloy powder is currently the important research object of additive manufacturing.Inconel 718 is widely used in aerospace and other fields as a superalloy material.However,the building process is prone to large temperature gradients and thermal stresses,resulting in problems with accuracy and quality.Using the characteristics of virtual and real fusion of digital twins to carry out research in SLM building simulation and experiment.It has important guiding significance for the optimization in superalloy materials of SLM building parameters.(1)Aiming at the temperature field and stress field of the SLM building process simulation.This paper takes Inconel 718 metal powder as the research object,and uses ABAQUS software to study the thermal-mechanical coupling transient temperature field,stress field and strain field in the building process.The morphology of the melt pool and the changing law of the state under different building parameters are analyzed.The results show that a moderate building parameter range can build a stable liquid melt pool,and the transient high temperature and stress reach a stable value,which provides a theoretical reference for further determining the optimal parameter combination.(2)Experimental research on SLM building process for process parameter optimization.According to the laser energy density,this paper designs different building parameters,including scanning speed,laser power and scanning distance,which carries out orthogonal experimental research on three factors at different levels.On the basis of simulating the temperature,stress and strain of the building process.The surface quality of the built part is analyzed,and the optimal parameter combination within the range of building parameters is selected as follows: the thickness of the powder layer is 0.05 mm,the scanning speed is 1000mm/s,the laser power is 180 W,and the scanning distance is0.1mm.Under the optimized process parameter combination,the surface of the SLM building part is flat,the width of the melt pool is uniform,the proportion of particle adhesion is low,and the microhardness value is large.(3)For the SLM intelligent optimization building process,this paper designs a digital twin system for SLM parameters optimization,and establishes the SLM building system framework from five levels: equipment layer,data layer,network layer,control layer and application layer.From the virtual space and physical entity level,the functional modules and processes are designed for different building stages,including overall building planning,process simulation and experiment data acquisition,to realize the intelligent building and parameter optimization control of SLM.