| Titanium alloy(Ti-6Al-4V)is widely used in aeronautic and aerospace fields due to its excellent performance.Additive/Subtractive Hybrid Manufacturing(A/SHM)combines the advantages of both additive manufacturing and subtractive manufacturing process,which can directly produce a complex component with high precision and quality.A/SHM provides new design ideas and manufacturing methods for the titanium alloy components,and has a broad development prospects.Laser Engineered Net Shaping(LENS)and milling experiments for the Ti-6Al-4V are conducted in this study.The effects of processing conditions on the microstructure and material properties,geometrical dimensions and surface integrity of the Ti-6Al-4V specimen are studied.The temperature field of LENS process is quantified and the microstructure distribution is analyzed.The milling experiments of additive-manufactured specimens with different initial temperatures are studied to investigate the effect of cutting parameters on the surface quality.The main research contents are as follows:(1)The single track and multi-layer LENS experiments are conducted to investigate the effects of processing parameters on the geometric feature and the microstructure.The temperature change and the hardness distribution was are studied;(2)A finite element model of heat transfer analysis for Ti-6Al-4V LENS process is established via ABAQUS.The element-birth-and-death method,Gaussian heat source model,forced-convection model and powder/solid material model are used in this model,which is verified by experimental results.The model predicts the temperature field of the molten pool,and thus the full temperature field of the additive manufactured specimen.(3)The milling experiments are conducted on the Ti-6Al-4V AMed and wrought parts.The effects of different cutting parameters on surface integrities are evaluated by the surface roughness,defects,microstructures and micro-hardness of the machined surface. |
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