TY - JOUR
T1 - Mechanical behavior of additively manufactured GRCop-84 copper alloy lattice structures
AU - Hazeli, Kavan
AU - June, Daniel
AU - Anantwar, Prathmesh
AU - Babamiri, Behzad Bahrami
N1 - Funding Information:
This investigation was supported by Mechanics of Materials and Structures (MOMS) program at the National Science Foundation (NSF), USA under the Award Number: 1943465 . We would like to thank Gabriel Demeneghi, Omar Mireles, and Paul Gradl at NASA Marshall Space Flight Center for sample production, discussion, and feedback.
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/8
Y1 - 2022/8
N2 - This study investigates the interplay between microstructure, topology and their combined effect on the quasi-static and dynamic behavior of additively manufactured Copper–Chromium–Niobium alloy (GRCop-84) lattice structures. Lattice structures made of GRCop-84 alloys are beneficial for wide range of applications due to the combination of the high strength and thermal conductivity imparted by GRCop-84 while minimizing weight and increasing the energy absorption through the use of the lattice structure. X-ray computed tomography (XCT) and optical microscopy were used to characterize the porosity and grain structure, respectively. Quasi-static and dynamic testing was performed on the as-built (AB) samples at strain rates of 10−1s−1 and 103s−1, respectively. The observations indicated that reducing the unit cell size from 4mm to 2mm led to a 66% reduction in porosity. Depending on the topology of the tested sample, the reduced porosity within the 2mm unit cell samples resulted in a 35% to 60% increase in the compressive yield strength. To understand whether topology is the only driving mechanism that influence the mechanical properties e.g., yield strength, the microstructure was altered through hot isostatic pressing (HIP) heat treatment while the topology was kept constant. It was noted that the 4mm unit cell size was more responsive to HIPing with a 40% reduction in porosity, while the 2mm unit cell size only experienced a 28% reduction in porosity. It was also noticed that there was a 48% reduction in porosity by minimizing the unit cell size from 4mm to 2mm in the case of the HIPed samples. Using this data, a correlation was recognized between microstructure and topology. It was found that HIPed samples experienced more plastic deformation and exhibited stress plateau that is common in cellular solids, indicating improved energy absorbing abilities compared to AB. AB Samples demonstrated higher compressive strength and failed due to the brittle nature of the AB microstructure. Lattice Structures with unit cell sizes of 4mm and 2mm experienced different collapse mechanisms, with 2mm unit cell lattices being topology dependent and 4mm unit cell lattices dependent on microstructure.
AB - This study investigates the interplay between microstructure, topology and their combined effect on the quasi-static and dynamic behavior of additively manufactured Copper–Chromium–Niobium alloy (GRCop-84) lattice structures. Lattice structures made of GRCop-84 alloys are beneficial for wide range of applications due to the combination of the high strength and thermal conductivity imparted by GRCop-84 while minimizing weight and increasing the energy absorption through the use of the lattice structure. X-ray computed tomography (XCT) and optical microscopy were used to characterize the porosity and grain structure, respectively. Quasi-static and dynamic testing was performed on the as-built (AB) samples at strain rates of 10−1s−1 and 103s−1, respectively. The observations indicated that reducing the unit cell size from 4mm to 2mm led to a 66% reduction in porosity. Depending on the topology of the tested sample, the reduced porosity within the 2mm unit cell samples resulted in a 35% to 60% increase in the compressive yield strength. To understand whether topology is the only driving mechanism that influence the mechanical properties e.g., yield strength, the microstructure was altered through hot isostatic pressing (HIP) heat treatment while the topology was kept constant. It was noted that the 4mm unit cell size was more responsive to HIPing with a 40% reduction in porosity, while the 2mm unit cell size only experienced a 28% reduction in porosity. It was also noticed that there was a 48% reduction in porosity by minimizing the unit cell size from 4mm to 2mm in the case of the HIPed samples. Using this data, a correlation was recognized between microstructure and topology. It was found that HIPed samples experienced more plastic deformation and exhibited stress plateau that is common in cellular solids, indicating improved energy absorbing abilities compared to AB. AB Samples demonstrated higher compressive strength and failed due to the brittle nature of the AB microstructure. Lattice Structures with unit cell sizes of 4mm and 2mm experienced different collapse mechanisms, with 2mm unit cell lattices being topology dependent and 4mm unit cell lattices dependent on microstructure.
KW - Additive manufacturing
KW - Copper alloys
KW - GRCop
KW - Lattice structures
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U2 - 10.1016/j.addma.2022.102928
DO - 10.1016/j.addma.2022.102928
M3 - Article
AN - SCOPUS:85131421234
SN - 2214-8604
VL - 56
JO - Additive Manufacturing
JF - Additive Manufacturing
M1 - 102928
ER -