TY  - JOUR
A1  - Abbas, Karim
A1  - Balc, Nicolae
A1  - Bremen, Sebastian
A1  - Skupin, Marco
T1  - Crystallization and aging behavior of polyetheretherketone PEEK within rapid tooling and rubber molding
JF  - Journal of Manufacturing and Materials Processing
N2  - In times of short product life cycles, additive manufacturing and rapid tooling are important methods to make tool development and manufacturing more efficient. High-performance polymers are the key to mold production for prototypes and small series. However, the high temperatures during vulcanization injection molding cause thermal aging and can impair service life. The extent to which the thermal stress over the entire process chain stresses the material and whether it leads to irreversible material aging is evaluated. To this end, a mold made of PEEK is fabricated using fused filament fabrication and examined for its potential application. The mold is heated to 200 ◦C, filled with rubber, and cured. A differential scanning calorimetry analysis of each process step illustrates the crystallization behavior and first indicates the material resistance. It shows distinct cold crystallization regions at a build chamber temperature of 90 ◦C. At an ambient temperature above Tg, crystallization of 30% is achieved, and cold crystallization no longer occurs. Additional tensile tests show a decrease in tensile strength after ten days of thermal aging. The steady decrease in recrystallization temperature indicates degradation of the additives. However, the tensile tests reveal steady embrittlement of the material due to increasing crosslinking.
KW  - additive manufacturing
KW  - fused filament fabrication
KW  - crystallization
KW  - polyetheretherketone
KW  - rapid tooling
Y1  - 2022
U6  - http://dx.doi.org/10.3390/jmmp6050093
SN  - 2504-4494
N1  - The article belongs to the Special Issue Advances in Injection Molding: Process, Materials and Applications
VL  - 6
IS  - 5
SP  - 1
EP  - 12
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Weiss, Christian
A1  - Heslenfeld, Jonas
A1  - Saewe, Jasmin Kathrin
A1  - Bremen, Sebastian
A1  - Häfner, Constantin Leon
T1  - Investigation on the influence of powder humidity in Laser Powder Bed Fusion (LPBF)
T2  - Procedia CIRP
N2  - In the Laser Powder Bed Fusion (LPBF) process, parts are built out of metal powder material by exposure of a laser beam. During handling operations of the powder material, several influencing factors can affect the properties of the powder material and therefore directly influence the processability during manufacturing. Contamination by moisture due to handling operations is one of the most critical aspects of powder quality. In order to investigate the influences of powder humidity on LPBF processing, four materials (AlSi10Mg, Ti6Al4V, 316L and IN718) are chosen for this study. The powder material is artificially humidified, subsequently characterized, manufactured into cubic samples in a miniaturized process chamber and analyzed for their relative density. The results indicate that the processability and reproducibility of parts made of AlSi10Mg and Ti6Al4V are susceptible to humidity, while IN718 and 316L are barely influenced.
KW  - LPBF
KW  - Additive Manufacturing
KW  - Powder Material
KW  - Humidity
Y1  - 2022
U6  - http://dx.doi.org/10.1016/j.procir.2022.08.102
SN  - 2212-8271
N1  - Teil der Sonderausgabe: 12th CIRP Conference on Photonic Technologies [LANE 2022]
VL  - 111
SP  - 115
EP  - 120
PB  - Elsevier
CY  - Amsterdam
ER  -