Metal Laser Hybrid Additive And Subtractive Manufacturing Processes And The CAE Analysis Of The Machine Structure

Laser hybrid additive and subtractive manufacturing processes methods introduces the traditional machining processes like drilling,milling and grinding into laser direct metal deposition(DMD)process and built a new methods of 3D laser manufacturing.In this thesis,the structural analysis of the hybrid machine tool and the process control of additive and subtractive are the two major studies.The machine tool structure was optimized by the structural analysis.The dimensional precision of the parts were guaranteed by the process control.In the CAE analysis of hybrid machine tool structure,the finite element model of the hybrid machine tool structure was established.The statics analysis of the hybrid machine tool structure were calculated under three loading condition including gravity state,milling state and drilling state.The modal analysis and the harmonic response analysis were carried out on this basis.The result shows that the static stiffness of the hybrid manufacturing machine tool being worse when the Y-axis is overstretched.The maximum deformation position is Z-axis.The finite element model of the hybrid machine tool structure is reasonable due to the matching between the calculation and the actual measurements.The 1st-5th natural frequency were given as 29.3Hz、35.4 Hz、54.5 Hz、55.7 Hz、104.3 Hz.The 1st～4th natural frequency was easier to be triggered.The process study of additive and subtractive was carried out in this thesis based on the hybrid machine tool.The importance of the coordination between additive reference frame and subtractive reference frame was found.The reason was analyzed and the cross-point method of additive frame and subtractive frame was put forward.Besides,the additive process test of 316L stainless steel was carried out.The optimized parameters of laser power,scanning speed,powder feeding rate,overlap rate and lifting capacity was obtained with the comparison of forming efficiency,contour accuracy and hardness.The effect of milling speed,depth of cut and feed per tooth on the processing quality were analyzed.The results show that the feed per tooth have effect on the surface roughness.Rather,the milling speed and the depth of cut have no effect on the surface roughness.The thickness of the hardened layer is less than 30μm during the small depth of cut.The work-hardening is not significant.Besides,the surface roughness of the additive 316L parts is less than the surface roughness of traditional 316L parts.The study of the structural analysis of the hybrid machine tool and the process control of additive and subtractive is identity of great theoretical significance and application value.