Additive Manufacturing: Alternative Processes (Beyond the Beam): Poster Session
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee, TMS: Powder Materials Committee
Program Organizers: Paul Prichard, Kennametal Inc.; Matthew Dunstan, US Army Research Laboratory; Peeyush Nandwana, Oak Ridge National Laboratory; Nihan Tuncer, Desktop Metal; James Paramore, Texas A&M University
Monday 5:30 PM
February 24, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr
A-41: Fabrication of Sub-microscale Metallic Glass Particles and Wires via High Pressure Atomization: Wan Kim1; Chae Woo Ryu1; Eun Soo Park1; Koji Nakayama2; 1Seoul National University; 2Tohoku University
Recently industrial fields related to nano devices have been required the advanced processes for manufacturing sub-microscale substances. Compare with the conventional alloys, metallic glasses (MGs) possess 10 times higher viscosity and surface tensions. Thus, it is possible to obtain the sub-microscale MG substances via atomization process. In the present study, we systematically investigated the high pressure atomization of the ZrCu-based glass-forming alloys to discover the universal expression for the size and morphology of atomized substances. First, we measured the thermal properties including the surface tension, viscosity and density of the molten alloys using electro-static levitation technique, and discussed the relationship among average diameter of particle and wire with those thermal properties. Secondly, we calculated Reynolds, Ohnesorge, and Weber number to solve the hidden mechanism of liquid jet break up mode. These results provide a novel guideline how to control the size and morphology down to nanometer scale by atomization process.
A-43: Production of Teaching Materials Through 3D Printing as Support for Educational Processes Related to the Sciences, Heritage and Culture: Henry Colorado1; David Mendoza1; Fernando León Valencia1; Juan Manuel Perdomo1; 1Universidad de Antioquia
This project aims to develop teaching materials through 3D printing to support educational processes related to science, heritage and culture associated to the Museum of the University of Antioquia, and greatly oriented to the education of the children visitors. Different pieces from local fauna have been selected mainly based on their potential impact over the environmental education. These parts were printed via fusion deposition modeling, an additive manufacturing inexpensive technique. The impact in teaching is presented as well as the potential impact in society, environment, and in the museum conservation pieces. A teaching model is also discussed in relation to engineering and arts. This project presents a collaboration between scientists, engineers and artists to give innovative solutions with impact in society.
A-44: Surface Characterization of IN718 Powder Stock and Influence on Net-shape HIP Microstructure: Benjamin Georgin1; Victor Samarov2; Hamish Fraser1; 1The Ohio State University; 2LNT
Net-shape hot isostatic pressing (HIP) is a promising manufacturing route for highly alloyed materials such as Ni-base alloys which are difficult to conventionally process. The application and performance of net-shape HIP components has been limited by characteristics of prior particle boundary (PPB) networks. These form as a direct result of oxygen contamination of powder stock which is highly dependent on the atomization processes and powder storage conditions. Clean atomization processes such as plasma rotating electrode process (PREP) minimize oxygen contamination. Oxygen is present both in the bulk and on the surface of the powders. In alloy 718, a nanoscale oxide layer forms on the powder surface due to the high concentration of oxide forming elements present. This study provides an in-depth characterization of surface oxidation of powder stock as well as the effect of powder size distribution (PSD) on PPB networks and microstructure in net-shape HIP components.
A-45: Temperature Dependent Thermal Conductivity of Metallic Powder Alloys for Additive Manufacturing: Faiyaz Ahsan1; Leila Ladani1; 1Arizona State University
Thermo-physical properties of metallic powders play a critical role in melting and solidification of powder during powder bed fusion process. Thermal conductivity is one of the most important thermo-physical properties. Furthermore, it is found that this property is a function of temperature. Measuring thermal conductivity of metallic powder at high temperatures is a very challenging task. Therefore, simulation of the powder bed fusion process is most often conducted using theoretical values of conductivity based on available analytical models which could result in inaccurate simulation results. Experimental measurements of this property at high temperature will fill this gap. In this work, a combination measurement of thermal diffusivity and thermal capacity is used to determine thermal conductivity of various common metallic powders used in additive manufacturing process up to 850 degree Celsius. The results were compared with available analytical models that were used to determine thermal conductivity of powders.
A-46: Thermal Analysis of Wire Arc Additive Manufacturing (WAAM): Lauriane Guilmois1; Philippe Le Masson2; Pascal Paillard3; 1Institut de Recherche Technologique (IRT) Jules Verne; 2Institut de Recherche Dupuy de Lôme (IRDL); 3Institut des Matériaux Jean Rouxel (IMN)
Compared to powder based additive manufacturing technologies, WAAM provides the advantage of generating large size components at a lower cost. However, to this day, it does not lead to parts as thin, accurate and flawless than powder techniques. The WAAM technological issues are closely linked to the operating parameters and to the thermal cycles endured by the piece during its production.<br>This work, dealing with Gas Metal Arc Welding (GMAW) process applied to the SS304L, aims:<UL><LI>to develop an equivalent source thermal model in order to predict temperature gradients underwent by metallic pieces;</LI><LI>to assess the impact of operating parameters (heat input, substrate thickness or deposition strategy) on the part distortion. </LI></UL><p> The final purpose is to conduct to the development of a numerical model coupling thermal, mechanical and metallurgical aspects of the WAAM process which should give the possibility to foresee distortions and thus to design sustainable pieces.</p>
A-47: Understanding Mechanisms Behind Morphological Changes in Gas Atomized Powders After Laser Irradiation: Jonathan Skelton1; Jerry Floro1; James Fitz-Gerald1; 1University of Virginia
In laser powder-bed additive manufacturing, gas atomized powder is most commonly used due to its high flowability during recoating. If morphological anomalies occur in particles that are either ejected from the melt pool, or located in a heat affected zone around the edges of the build, defects could ensue due to changes in the rheology of the powder, resulting in uneven recoating after sieving operations. This research focuses on morphological changes observed in an Al-Cu eutectic alloy powder (1-100μm diameter) irradiated with a CW laser diode (450nm wavelength, power density = 8,000 W/cm2) on ITO-coated glass substrates. Particles were characterized with scanning electron microscopy before and after irradiation, clearly showing changes in microstructure and a range of collapsed surface features. Microstructural evidence suggests that the mechanism that produces these collapsed morphologies involves particles melting and solidifying within their oxide shell. Support of the NSF under grant DMR-1663085 is gratefully acknowledged
A-48: Wire+arc Additive Manufacturing for Fabrication of Bimetallic Additively Manufactured Structures: Rumman Ahsan1; Xuesong Fan2; A. N. M. Tanvir1; Gi-Jeong Seo1; Changwook Ji3; P. K. Liaw2; Duck Bong Kim1; 1Tennessee Technological University; 2The University of Tennessee, Knoxville; 3Korea Institute of Industrial Technology
Wire+arc additive manufacturing (WAAM) technology adopts existing arc welding equipment and consumables to fabricate a part additively depositing metal in near net shape. High deposition rate, a large selection of materials, low material and equipment costs and adequate structural integrity are some characteristics of the WAAM process. In addition, WAAM technology can deposit more than one metal simultaneously or subsequently to have a combination of complementary material properties within the same structure along with cost optimization. In this work, integral bimetallic additively manufactured structures (BAMS) of two materials namely austenitic stainless steel and Inconel 625 was successfully deposited. A gradient of microstructure, hardness, and composition was observed at the interface for both structures. Microstructure, elemental composition, and mechanical properties were characterized and discussed. The study demonstrates the suitability of WAAM process to fabricate the multi-functional component as an integral part.