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Qualification of AM materials under component service conditions
Event finished
Free event
News from the AM scene with Michael Krämer from the AMC in Darmstadt about "Qualification of AM materials under component service conditions"
Event finished
Free event
Event language
- German
News from the AM scene with Michael Krämer from the AMC in Darmstadt about "Qualification of AM materials under component service conditions"
Universität Darmstadt
The qualification of additively manufactured materials for safety-critical components in mechanical engineering places high demands on service life assessment. Laser powder bed fusion (PBF-LB/M) produces microstructural features such as porosity, roughness, and orientation-dependent grain structures that influence mechanical behavior under operating conditions (fatigue and creep loading). Even though the performance of AM components is often equivalent to or higher than that of conventionally manufactured variants, these effects must be taken into account in the design at an early stage of development.
The presentation shows combined research work on nickel materials aimed at material qualification under realistic operating conditions. For cyclic loads, a model approach is presented that integrates the cyclic R-curve to more accurately represent the transition between short and long crack growth. This approach allows a fracture mechanics-based evaluation of the process-characteristic defect structure and determination of fatigue strength without extensive testing.
Figure 1: left: schematic threshold test procedure with compression pre-cracking; right: SENT specimen equipped with ACPD crack montoring
For long-term creep loading, component extracted samples and witness blank specimens are tested for over 10,000 hours to determine the influence of structural orientation and design features on creep resistance. The results show the life-relevant influences of design and production aspects on long-term behavior.
Figure 2: Overview AM-specific sample geometries
The methods presented contribute to the robust qualification of PBF-LB/M components and enable accelerated development cycles while increasing safety reserves in turbomachinery applications.
Figure 3: overview of tensile properties for witness and extracted samples
About the speaker:
Dr.-Ing. Michael Krämer is General Manager of the Additive Manufacturing Center (AMC) at TU Darmstadt and has more than 12 years of experience in research on high-temperature and additively manufactured materials. He completed his doctorate on crack behavior in nickel alloys in 2018. His work focuses on the use of new testing methods and research into process-microstructure-property relationships for the efficient qualification of safety-critical components from additive manufacturing for mechanical engineering. Dr. Krämer is active in several national and international committees on material behavior (DVG, DGM, ASTM, ASME).
The presentation shows combined research work on nickel materials aimed at material qualification under realistic operating conditions. For cyclic loads, a model approach is presented that integrates the cyclic R-curve to more accurately represent the transition between short and long crack growth. This approach allows a fracture mechanics-based evaluation of the process-characteristic defect structure and determination of fatigue strength without extensive testing.
Figure 1: left: schematic threshold test procedure with compression pre-cracking; right: SENT specimen equipped with ACPD crack montoring
For long-term creep loading, component extracted samples and witness blank specimens are tested for over 10,000 hours to determine the influence of structural orientation and design features on creep resistance. The results show the life-relevant influences of design and production aspects on long-term behavior.
Figure 2: Overview AM-specific sample geometries
The methods presented contribute to the robust qualification of PBF-LB/M components and enable accelerated development cycles while increasing safety reserves in turbomachinery applications.
Figure 3: overview of tensile properties for witness and extracted samples
About the speaker:
Dr.-Ing. Michael Krämer is General Manager of the Additive Manufacturing Center (AMC) at TU Darmstadt and has more than 12 years of experience in research on high-temperature and additively manufactured materials. He completed his doctorate on crack behavior in nickel alloys in 2018. His work focuses on the use of new testing methods and research into process-microstructure-property relationships for the efficient qualification of safety-critical components from additive manufacturing for mechanical engineering. Dr. Krämer is active in several national and international committees on material behavior (DVG, DGM, ASTM, ASME).
