Figures & data
2 a Typical particle size distribution of a gas atomised powder (here: CMSX-4), b Ti–6Al–V4: SEM of the powder particles. Non-spherical particles, particle agglomerates and satellites are visible. c Sintered powder block (Ti–6Al–4V), d c after removing the powder by sand blasting with the same powder
![2 a Typical particle size distribution of a gas atomised powder (here: CMSX-4), b Ti–6Al–V4: SEM of the powder particles. Non-spherical particles, particle agglomerates and satellites are visible. c Sintered powder block (Ti–6Al–4V), d c after removing the powder by sand blasting with the same powder](/cms/asset/bf7832a4-dece-4ad4-a1d8-7d7ba9bbcf33/yimr_a_1176289_f0002_c.jpg)
3 Heating and melting during SEBM. At the top: photograph during the process. At the bottom: schematic of the beam movement. a Heating by quasi-multi-beam scanning of the total building area with a defocused beam, b Melting by hatching, c Quasi-multi-beam contour melting by jumping from point to point
![3 Heating and melting during SEBM. At the top: photograph during the process. At the bottom: schematic of the beam movement. a Heating by quasi-multi-beam scanning of the total building area with a defocused beam, b Melting by hatching, c Quasi-multi-beam contour melting by jumping from point to point](/cms/asset/a8ed8755-d6c1-42e7-bea4-29aedde259ff/yimr_a_1176289_f0003_c.jpg)
4 Evaporation effects: a Exemplary melt surfaces of 15 × 15 × 10 mm³ cubic samples. Left: good surface, right: poor surface with a characteristic pattern induced by material displacement, bottom: Simulation to illustrate the mechanism of melt displacement. The beam moves from left to right up to 16 times leaving behind a built-up area and a deep hole. b Element mapping showing the Al distribution in Ti–48Al–2Cr–2Nb, c Layered microstructure as built in Ti–48Al–2Cr–2Nb
![4 Evaporation effects: a Exemplary melt surfaces of 15 × 15 × 10 mm³ cubic samples. Left: good surface, right: poor surface with a characteristic pattern induced by material displacement, bottom: Simulation to illustrate the mechanism of melt displacement. The beam moves from left to right up to 16 times leaving behind a built-up area and a deep hole. b Element mapping showing the Al distribution in Ti–48Al–2Cr–2Nb, c Layered microstructure as built in Ti–48Al–2Cr–2Nb](/cms/asset/725d3a46-6d7f-4f96-b16e-18fb62b55150/yimr_a_1176289_f0004_c.jpg)
5 Grain structure of different materials processed by SEBM: a Pure copper,Citation12 b Ti–6Al–4V c Ti–48Al–2Nb–2Cr at the surfaceCitation13
![5 Grain structure of different materials processed by SEBM: a Pure copper,Citation12 b Ti–6Al–4V c Ti–48Al–2Nb–2Cr at the surfaceCitation13](/cms/asset/2e2ffdd3-d2e8-43de-902c-4faaac14db7f/yimr_a_1176289_f0005_c.jpg)
6 In-situ heat treatment during SEBM: Schematic of the temperature evolution at a fixed point of the component where the beam passes several times in each layer. A simulated temperature evolution at different depths (in steps of 100 µm) for Ti–6Al–4V is shown to visualise the time scale of temperature variation near the surface during and after melting
![6 In-situ heat treatment during SEBM: Schematic of the temperature evolution at a fixed point of the component where the beam passes several times in each layer. A simulated temperature evolution at different depths (in steps of 100 µm) for Ti–6Al–4V is shown to visualise the time scale of temperature variation near the surface during and after melting](/cms/asset/279f3747-0d0a-492a-82f1-cdfc2dd2b1f8/yimr_a_1176289_f0006_c.jpg)
7 In-situ heat treatment during SEBM: a Nickel-base alloy CMSX-4 (schematic). Middle: Micrograph of the sample with elongated grains. Left: Homogenisation (LOM), Right: Aging of the γ’-particles (SEM) (see also Ref. Citation16), b Nickel-base alloy IN718: the niobium-rich δ-phase is precipitated in the interdendritic areas with columnar architecture
![7 In-situ heat treatment during SEBM: a Nickel-base alloy CMSX-4 (schematic). Middle: Micrograph of the sample with elongated grains. Left: Homogenisation (LOM), Right: Aging of the γ’-particles (SEM) (see also Ref. Citation16), b Nickel-base alloy IN718: the niobium-rich δ-phase is precipitated in the interdendritic areas with columnar architecture](/cms/asset/b596da62-298d-46aa-a064-9ede051f6329/yimr_a_1176289_f0007_c.jpg)
Table 1 SEBM materials
9 Influence of the building parameters on the microstructure and properties of Ti–6Al–4V. Top: Microstructure for different beam velocities and total energy input per volume. Bottom, left: Thickness of the α–lamella as a function of the volume energy. Bottom, right: Strength as a function of the α–lamella thickness (adapted from Ref. Citation28)
![9 Influence of the building parameters on the microstructure and properties of Ti–6Al–4V. Top: Microstructure for different beam velocities and total energy input per volume. Bottom, left: Thickness of the α–lamella as a function of the volume energy. Bottom, right: Strength as a function of the α–lamella thickness (adapted from Ref. Citation28)](/cms/asset/36346f83-ab91-411a-9d08-897aab10d54b/yimr_a_1176289_f0009_c.jpg)
10 Influence of different processing strategies on the grain structure of IN718. SEM-micrograph showing a columnar grain structure a and an equiaxed grain structure b in a longitudinal section parallel to the building direction (for details see Ref. Citation25)
![10 Influence of different processing strategies on the grain structure of IN718. SEM-micrograph showing a columnar grain structure a and an equiaxed grain structure b in a longitudinal section parallel to the building direction (for details see Ref. Citation25)](/cms/asset/79403729-48e1-449c-8ad0-c6cc874999a1/yimr_a_1176289_f0010_b.gif)
11 Typical small spherical defect in EBM γ-TiAl specimens a; as-built microstructure after EBM b; microstructure after HIP c; microstructure after thermal treatment d (courtesy of Ref. Citation56)
![11 Typical small spherical defect in EBM γ-TiAl specimens a; as-built microstructure after EBM b; microstructure after HIP c; microstructure after thermal treatment d (courtesy of Ref. Citation56)](/cms/asset/e131b728-a8a4-4abb-8a9a-d3c3579c2655/yimr_a_1176289_f0011_c.jpg)
12 Cellular structures and materials. a Pure copper component with a cellular core, b Reactor (stainless steel 1.4404) for hydrogen release from perhydro-N-ethylcarbazole,Citation77 c Normal Ti–6Al–4V lattice structure (anticlastic) versus auxetic structure (synclastic) (adapted from Ref. Citation93)
![12 Cellular structures and materials. a Pure copper component with a cellular core, b Reactor (stainless steel 1.4404) for hydrogen release from perhydro-N-ethylcarbazole,Citation77 c Normal Ti–6Al–4V lattice structure (anticlastic) versus auxetic structure (synclastic) (adapted from Ref. Citation93)](/cms/asset/1d1ded41-f78c-4f9b-b230-72558c272ff0/yimr_a_1176289_f0012_c.jpg)