PSI - Issue 5

David Palousek et al. / Procedia Structural Integrity 5 (2017) 393–400 Vendula Kratochvilova et al. / Structural Integrity Procedia 00 (2017) 000 – 000

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Chemical composition of AlCu2Mg1.5Ni metal powder for SLM production was similar to the conventionally produce one and it is shown in the table 1.

Table 1. Chemical composition (wt %) of reference and SLM material AlCu2Mg1.5Ni Element Si Fe Cu Mg Ni

Ti

Reference material 1.24 %

1.1% 1.0 %

2.5 %

1.5 %

1.2 %

0.4 % 0.2 %

SLM powder

0.15 %

2.66 %

1.39 %

1.22 %

The microstructure of SLM material AlCu2Mg1.5Ni is shown on the Fig. 3a. The microstructure was inhomogeneous with clearly visible layer boundaries and big amount of defects (pores and shrinkages) located near to them.

2.2. Copper alloy

Used SLM Cu alloy was Cu7.2Ni1.8Si1Cr and as reference material conventionally produced (extruded) alloy AMPCOLOY® 944 (Cu7Ni2Si1Cr) with similar chemical composition, see the table 2. In total it was produced 8 specimens from SLM material and 7 specimens from AMPCOLOY® 944.

Table 2. Chemical composition (wt %) of reference material Cu7Ni2Si1Cr and SLM material Cu7.2Ni1.8Si1Cr Element Ni Si Cr Others Reference material 7.7 % 2 % 1 % 0.5 % SLM powder 7.5 % 1.8 % 0.94 % 0.114 %

The machine SLM Solution 280HL was also used for the production and the production parameters were determine on the basis of previous relative density tests (best relative density was 99.5 %). The SLM parameters for Cu alloy were:

 Laser power: 400 W  Scanning speed: 1100 mm/s  Hatch distance: 90 µm  Beam diameter: 82 µm

The microstructure of SLM Cu alloy is shown on the Fig. 3b. Similar to Al alloy the layer boundaries are clearly visible, but the amount of defects is much lower.

Fig. 3. (a) microstructure of Al SLM alloy; (b) microstructure of Cu SLM alloy