3D printing History of engineering & technology 25 Technology: general issues 13 additive manufacturing 12 mechanical properties 11 microstructure 9 finite element analysis 7 surface roughness 6 PLA 5 corrosion 5 machining 5 ABS 4 FDM 4 Materials science 4 aluminum 4 biomedical 4 forming 4 fused deposition modeling 4 fused deposition modeling (FDM) 4 fused filament fabrication 4 infill density 4 magnesium 4 rapid prototyping 4 scaffolds 4 simulation 4 titanium 4 4D printing 3 CFRP 3 FEM 3 Inconel 718 3