Additive Manufacturing for Energy Applications III: Poster Session
Sponsored by: TMS Structural Materials Division, TMS: Additive Manufacturing Committee, TMS: Nuclear Materials Committee
Program Organizers: Isabella Van Rooyen, Pacific Northwest National Laboratory; Indrajit Charit, University of Idaho; Subhashish Meher, Idaho National Laboratory; Michael Kirka, Oak Ridge National Laboratory; Kumar Sridharan, University of Wisconsin-Madison; Xiaoyuan Lou, Purdue University
Tuesday 5:30 PM
March 16, 2021
Room: RM 1
Location: TMS2021 Virtual
Session Chair: Michael Kirka, Oak Ridge National Laboratory
Additive Manufacturing of Nuclear Spacer Grids using Inconel 718 Alloy: Observed Distortion and Proposed Distortion Control Measures for Thin Walled Structures: Syed Zia Uddin1; Jack Beuth1; Qu He1; 1Carnegie Mellon University
Nuclear spacer grids, an intricate consumable part of a nuclear fuel assembly, currently require lead time of more than two years from order placement to delivery using conventional fabrication methods. Laser Powder Bed Fusion (LPBF) type Additive Manufacturing (AM) process could reduce the lead time and cost significantly by printing out the structure in one major step. However, one of the main challenges in LPBF fabrication is the buckling type deformation of the tall thin walls that are abundant in the current spacer grid design. In this research, LPBF fabrication and finite element simulation of the simplified spacer grid structures with a wall thickness of 300μm and height of 47mm (~1.5inch) were performed. To eliminate the observed buckling deformation, different stiffening modifications were introduced to the thin walled cross section of the spacer grid structure. Findings in the current research would facilitate successful LPBF fabrication of tall thin wall structures.
Aid of Additive Manufacturing of 2D Materials for Miniaturization: Yingtao Wang1; Annie Xian Zhang1; 1Stevens Institute of Technology
High-quality 2D crystal growth has been studied with increasing interest. While the roll-to-roll processing has demonstrated success in growing and transferring large-area graphene samples, the layer-by-layer pattern transfer technology for a scalable and continuous fabrication of 2D heterostructures is unavailable for flexible substrate applications. To pattern 2D layers using conventional photolithography or e-beam lithography, poly(methyl methacrylate) (PMMA) or a similar polymer is introduced as a lithography mask. This exposure of 2D materials to polymers often introduces unwanted doping and reduced carrier mobility. In this work, we simulated the thermal additive manufacturing process to enable the continuous fabrication of 2D heterostructure on a flexible substrate. The key idea is to apply the thermal laser printing principle to the additive manufacturing process to precisely induce the local melting which ultimately results in the 2D materials etching.
Development of Additive Manufacturing Processes for Embedding Thermocouples during Directed Energy Deposition: Matthew McCoy1; Kyu Cho1; John Shelton1; Piyush Sabharwall1; Isabella Van Rooyen1; 1Northern Illinois University
In the investigation, the primary process parameters of metal additive manufacturing (MAM) that affect the melt pool were examined to allow for a thermocouple embedment such that the sensor is capable of measuring temperatures within a standard operating temperature range for next generation heat exchangers, while maintaining an acceptable error listed by the manufacturer. Developing a melt pool capable of properly embedding a thermocouple is not only important for accurate temperature measurements but is critical in ensuring that standards for MAM parts are met, such as standards for 316L stainless steel powder. While the core of the investigation was to embed a thermocouple and confirm that the embedded sensor yields the same value for a nominal temperature as a sensor that is attached through traditional manufacturing processes, the part surrounding the embedded thermocouple must abide by industry standards so that it can be used in desired engineering applications.
Effect of Cold Rolling on the Microstructure and the Mechanical Properties of 316L Stainless Steel Parts Produced by Laser Powder Bed Fusion (LPBF): Louis Lemarquis1; Pierre-François Giroux1; Hicham Maskrot1; Bassem Barkia1; Olivier Hercher1; Frédéric Bondiguel1; Philippe Castany2; 1Université Paris-Saclay, CEA; 2Université de Rennes, INSA Rennes
Additive Manufacturing (AM) technologies provide new opportunities to enhance some piece-producing processes in the industry: AM offers the possibility to produce complex-shaped parts, and microstructures from Laser Powder Bed Fusion (LPBF) can heavily differ from microstructures usually obtained through traditional processes. In this work, several LPBF preforms were constructed along different directions and then cold rolled at different deformation rates. Two 316L powders that produce two different microstructures were used: one exhibiting columnar grains and the other equiaxed ones. These two obtained microstructures were studied by EBSD, along with a study focused on the tensile properties. The first results show that the LPBF 316L is ductile while being more resistant than the traditional 316L. Furthermore, the material deformation is mostly due to mechanical twinning, which is similar compared to the standard 316L. The final goal of this study is to analyse the potentialities of combining LPBF and traditional manufacturing processes.
Experimental Fabrication of Porous Additive Manufactured Material: Luis Nuñez1; Isabella Van Rooyen2; 1Northern Illinois University; 2Idaho National Laboratory
Nuclear industries can benefit from materials that perform well mechanically and thermally in high temperature and corrosion environments. Functionally graded materials (FGM) are materials manufactured with complex spatial, structural, and chemical compositions, creating components predesigned with tailored microstructural and mechanical properties. Porosity-graded FGMs are designed to introduce pores into a component’s structure as a mechanism to increase bulk or surface material performance, such as stress accommodation and negative thermal conductivity. Additive manufacturing (AM) techniques such as laser engineered net shaping (LENS) and wire arc additive manufacturing (WAAM), excel in high energy density, point-to-point metal deposition, and present in conjunction with other combinatorial approaches, exciting methods to manufacture porous FGM components. Plasma jet printing is also examined as another means of fabrication method evaluations for smaller scale graded components. This study explores AM FGM process parameters, combinatorial fabrication methodologies and preliminary characterization results for components functionally graded in porosity levels.
Numerical Study to Predict the Effect of Surface Roughness on the Thermal and Hydraulic Performance of Additively Manufactured Heat Exchangers: Jose Gonzalez1; Kyu Cho1; John Shelton1; Piyush Sabharwall1; Isabella Van Rooyen1; 1Northern Illinois University
This study will fundamentally investigate the effect of surface roughness on the thermal and velocity boundary layers for various surface roughness profiles with physics-based computational modeling. To accurately model the surface roughness effect on thermohydraulic performance, correlations like roughness ratio, friction factor, and Nusselt number are investigated. This study expects to indicate correlations for different flow regimes which can successfully predict the effect of surface roughness on thermohydraulic performance. Results generated from modeling surface roughness effect with unique correlations are then compared to experimental data obtained from literature for validation. The results of this study will provide insight to understand the thermal fluid physics associated with surface roughness and design guidelines for heat exchangers produced with additive manufacturing.
On the In-situ Formation of Nano Oxides during Laser Powder Bed Fusion as a Function of Steel Chemistry and Atmospheric Oxygen Level: Houshang Yin1; Pu Deng1; Miao Song2; Mallikarjun Karadge3; Xiaoyuan Lou1; 1Auburn University; 2University of Michigan-Ann Arbor; 3GE Research
Efforts have been made to understand the origins of in-situ nano-oxide formation during laser powder bed fusion (LPBF). This work aims to obtain insights into the oxidation pathway and nano-oxide dispersion during LPBF to support the efficient production of oxide dispersion strengthened (ODS) alloys by laser additive manufacturing (AM). Three austenitic stainless steels alloyed with different elements (have different oxygen affinity), Y, Al, and Si respectively, were used for fabrication in AM machine with varied atmospheric oxygen levels and laser parameters. The oxidations of spattered powders and melt pool surface were identified as main contributors to oxygen intrusion. The amount, size, distribution of the oxide in AM stainless steel were found sensitive to the type of oxygen getter, alloying concentration, and energy input. Depending on the alloying elements, post-process heat treatment can influence the evolution of the nano-oxides, which was revealed by oxide characterization and micro/nanoindentation.
Process-induced History Effects on the Creep Behavior of Additively Manufactured IN718 Alloys: Saurabh Sharma1; Kiran Solanki1; 1Arizona State University
Nickel based superalloy IN718 is widely used in transportation industries at elevated temperatures; however, the complexity in design limits its operational efficiency and conventional manufacturing ability. Additive manufacturing (AM) can overcome it by producing near net shape components; however, a thorough understanding of mechanical behavior at elevated temperature is required before its actual use. In this work, process-induced history effects on the creep behavior in an additively manufactured IN718 alloy was investigated. In particular, three different heat treatment routes were chosen to tailor the microstructure by having the specific dissolution of precipitated phases. Microstructural observations were performed to verify the dissolution of phases after heat treatment. Compression and tensile creep experiments were performed on the specimens build in different orientations. Results showed that the creep properties were dependent on the nature of phases present and are comparable to wrought behavior with a proper heat treatment condition.