**3. Various AM approaches for Ti-6Al-4V and their key processing parameters**

#### **3.1. Selective Laser Melting (SLM)**

There are a variety of suppliers providing reliable SLM machines for producing AM Ti-6Al-4V [29-46]. EOSINT M270, Trumpf LF250, and SLM Solutions are well known SLM facilities. Figure 2 shows a schematic graph to present the working principle of the SLM [46]. Table 3 provides a summary about the key machine parameters and working conditions via a typical SLM machine, SLM 280 HL [29-46].


**Table 3.** Typical technical parameters of the SLM [29-46].

An Overview of Densification, Microstructure and Mechanical Property of Additively Manufactured Ti-6Al-4V… http://dx.doi.org/10.5772/59275 81

**Figure 2.** Schematic graph to show the working principle of the SLM [46].

#### **3.2. Electron Beam Melting (EBM)**

**Mechanical property Value** Tensile strength, yield (*σ0.2*) 880 MPa Tensile strength, Ultimate (UTS) 950 MPa Elongation (*ε*) 14 % Reduction of Area (*R*) 36% Hardness, *Hv* 349 Young's modulus (*E*) 113.8 GPa Poisson's ratio (*υ*) 0.342

Fracture toughness 75 MPa•m1/2

cycles and *K* = 3.3) 240 MPa

**Table 2.** Mechanical properties of Ti-6Al-4V achievable via forged- then-annealed [14,15,27,28]

cycles) 510 MPa

**3. Various AM approaches for Ti-6Al-4V and their key processing**

**Parameter**

**Scanning speed** Up to 15000 mm/s (mostly 125 mm/s – 802 mm/s)

**Substrate** Without substrate; or with self-substrate heated up to 700°C

There are a variety of suppliers providing reliable SLM machines for producing AM Ti-6Al-4V [29-46]. EOSINT M270, Trumpf LF250, and SLM Solutions are well known SLM facilities. Figure 2 shows a schematic graph to present the working principle of the SLM [46]. Table 3 provides a summary about the key machine parameters and working conditions via a typical

Fatigue strength (at 1\*107

80 Sintering Techniques of Materials

**parameters**

Fatigue strength (unnotched at 1\*107

**3.1. Selective Laser Melting (SLM)**

SLM machine, SLM 280 HL [29-46].

**Typical equipment** SLM 280HL

**Laser type** YLR Fibre Laser **Laser beam size** 70 μm - 120 μm

**Feed type** 5 μm – 50 μm

**Build density** 99.7% - 100%

**Table 3.** Typical technical parameters of the SLM [29-46].

**Layer thickness** Mostly 20 μm – 75 μm **Build temperature** Mostly naturally heated

**Build volume** 280 mm \* 280 mm \* 350 mm

**Atmosphere during processing** With protection by Ar, N2 or He

Arcam provides a variety of EBM machines for processing Ti and Ti alloys, including Arcam A1, A2, S12 and S400, and it dominates the market for the time being [47-66]. Figure 3 provides a schematic graph to show the working principle of the EBM [66]; key machine parameters and working conditions are summarised into Table 4 via a typical example of Arcam A2 EBM.


**Table 4.** Typical technical parameters of the EBM [47-66].

**Figure 3.** Schematic graph to show the working principle of an EBM equipment [66].

#### **3.3. Laser Metal Deposition (LMD)**

A variety of LMD machines and laser systems are being used for the fabrication of metals and alloys including Ti-6Al-4V, such as LEMS TM Nd:YAG, Trumpf HLD 3504 Yb:YAG and IPG with Yb fibre laser [67-78]. Figure 4 and Table 5 present the general working principle, working conditions and key machine/processing parameters.

**Figure 4.** Schematic graph to show the working principle of an LMD equipment [76].


**Table 5.** Typical technical parameters of the LMD [67-76].

#### **3.4. Selective Laser Sintering (SLS)**

**3.3. Laser Metal Deposition (LMD)**

82 Sintering Techniques of Materials

conditions and key machine/processing parameters.

**Figure 3.** Schematic graph to show the working principle of an EBM equipment [66].

**Figure 4.** Schematic graph to show the working principle of an LMD equipment [76].

A variety of LMD machines and laser systems are being used for the fabrication of metals and alloys including Ti-6Al-4V, such as LEMS TM Nd:YAG, Trumpf HLD 3504 Yb:YAG and IPG with Yb fibre laser [67-78]. Figure 4 and Table 5 present the general working principle, working

EOSINT M250X and EOISNT M270 are being used as the SLS machines for preparing AM Ti-6Al-4V [79-88]. The general working conditions and key machine/processing parameters are shown by Figure 5 and listed in Table 6.

**Figure 5.** Schematic graph to show the working principle of an SLS equipment [88].


**Table 6.** Typical technical parameters of the SLS [77-88].
