PSI - Issue 53

Francisco Matos et al. / Procedia Structural Integrity 53 (2024) 270–277

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Francisco Matos et al. / Structural Integrity Procedia 00 (2023) 000–000

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was the cutting material of choice given its remarkable durability in aluminium machining, ensuring that this tool would have an extended lifespan. The tool features four through-holes that allow the connection between the cutter body and the milling tool holder by means of four DIN 912 M3 x 16 screws. An entrance channel featuring a circular cross-section with a diameter of d channel = 1.7 mm was defined for each cutting tooth. This entrance channel then divides itself into two channels that direct the fluid from the tool to each insert cutting zone. Sharp corners, abrupt changes of direction or channel diameter were avoided during the design phase.

Fig. 1: Three-dimensional CAD model of the additively manufactured milling tool showing constructive details.

2.2. Printing setup, material and parameters

The printing process starts with a pre-processing step where the scale, layout, position, and orientation of the part is set by the operator, and then finally transferred to the AM machine. The developed tools were printed using a GE Concept Laser M2 powder bed fusion system with a 245 x 245 x 350 mm build chamber. Process parameters and laser beam scanning strategies were implemented within the Materialise Magics software. Laser power up to 300 W, spot size of 130 µ m and a hatch space of 130 µ m were used. Layer thickness was set to 50 µ m , resulting in the deposit and melting of 362 layers of powder to achieve the milling tool. All printings were carried out in a nitrogen environment. Stainless steel AISI 316L was selected as the material for manufacturing the tooling prototypes given its good compromise between corrosion resistance, durability and printability. The production of two tool prototypes via laser powder-bed fusion took 2.5 hours.

3. Material and functionality assessment of AM milling tool

3.1. Material assessment

The chemical composition of the printed AISI 316L was evaluated by optical emission spectrometry using a spark emission spectroscopy, the SPECTROMAXX metal analyser equipment. Measured chemical composition is reported inTable 1.

Table 1: Chemical composition (wt.%) of 316L powder, measured and according to ASTM-F3184-16.

Element

C Mn P

S

Si

Cr

Ni

Mo Fe

Min

16.00 10.0 2.0

Measured 0.020 1.40

< 0.001

< 0.001 0.68 16.78 12.42 2.35 Bal.

Max

0.030 2.00 0.045 0.030 1.00 18.00 14.0 3.0