Additive Manufacturing of Metals: Microstructure, Properties and Alloy Development: Additive Manufacturing: Miscellaneous
Program Organizers: Prashanth Konda Gokuldoss, Tallinn University of Technology; Juergen Eckert, Erich Schmid Institute of Materials Science; Zhi Wang, South China University of Technology
Wednesday 2:00 PM
October 20, 2021
Room: A120
Location: Greater Columbus Convention Center
Session Chair: Roman Maev, University of Windsor
2:00 PM
Additive Manufacturing of Metallic Materials: Mechanical Properties: Prashanth Konda Gokuldoss1; 1Tallinn University of Technology
Laser-based powder bed fusion processes like selective laser melting are one of the additive manufacturing (AM) processes that produce 3-D metal parts from CAD data. Until now, only conventional alloys like the AlSi10Mg, 316L, etc. that either is developed for cast or wrought processes have been used for fabrication. Some of the alloys work well for the AM process like the Al12Si, AlSi10Mg because they have good fluidity and are readily weldable. Nevertheless, most of the materials fabricated by SLM show superior mechanical properties. Even though superior mechanical properties were recorded, there are reports showing the premature failure of the materials (i.e.) the material fail before they achieve their maximum strength. Some of the reasons behind this premature failure will be discussed in detail.
2:20 PM
Advancements in High Pressure Heat Treatment for AM Parts: Chad Beamer1; 1Quintus Technologies
The use of HIP is of growing interest for AM parts with significant research efforts in place to mature and optimize these systems. Historically HIP has been used to eliminate internal cracks, voids, and pores with subsequent heat treatment performed using conventional technologies to obtain the desired microstructure and mechanical performance. Recently it has been shown in literature and practice that it is possible to integrate HIP and heat treatments in the HIP furnace with the aid of high-pressure gas cooling or quenching, an approach known as High Pressure Heat Treatment(HPHT). One recent development advancing the HPHT technology is steered cooling. Steered cooling enables the HIP system to now cool based on component temperature at a predefined rate for targeting desired material properties. This presentation will cover the most recent HPHT advancements and learnings and review HPHT cast studies performed on AM alloys highlighting both material performance and productivity improvement.
2:40 PM
Avoiding Deleterious Phase Formation in Abrupt Interface Bonding of Multi-material Structures: Nicholas Jones1; Jack Beuth1; Maarten de Boer1; 1Carnegie Mellon University
Multi-material additive manufacturing allows for the fabrication of a wide range of functional structures, but care must be taken to account for crystal structure incompatibility between alloys. Intermetallics, oxides, carbides, and other brittle phases often form when joining dissimilar materials. Often this results in cracking, delamination, and mechanical failure at the bond between metals. In this work, we identify several key methods to avoid deleterious phase formation in multi-material fabrication. Thermodynamic simulations utilizing the CALPHAD method are performed to identify possible phases to avoid in processing before experimentation. Several fabrication methods are tested via directed energy deposition processing, producing defect-free material interfaces. Microscopy and compositional analysis are performed at material interfaces to verify phase predictions. Heat treatments are also done to determine the sensitivity of material interfaces to thermal cycling and high temperature applications.
3:00 PM
Controlling High Temperature Mechanical Performance of Superalloys Fabricated via Laser Powder Bed Fusion through Processing Parameter Variation: Nicholas Lamprinakos1; Joseph Pauza1; Anthony Rollett1; 1Carnegie Mellon University
Superalloys are valued for their superior mechanical performance at elevated temperatures. For certain applications, such as high temperature heat exchangers with complex geometries, it can be advantageous to produce superalloy parts via additive manufacturing (AM). However, depending on the processing parameters used, the microstructures of the parts produced via AM can vary greatly. This can lead to variation in mechanical properties. As a result, there is potential to optimize mechanical performance through process parameter variation. In this work, elasto-viscoplasitc fast Fourier transform crystal plasticity simulations were used to predict the mechanical response of synthetic microstructures generated using a modified Potts model approach. Simulated processing parameters were altered to evaluate parameter effects on mechanical response. The simulation results were used to select parameters for printing superalloy mechanical testing coupons. High temperature mechanical testing was performed to evaluate the extent to which mechanical performance at elevated temperature can be controlled.
3:20 PM
No On-Demand Only: Effects of Extrusion-based Additive Manufacturing on Thermoelectric Transport in Nickel and Bismuth: Victoria Stotzer1; Christian Apel1; Sarah Watzman1; Ashley Paz y Puente1; 1University of Cincinnati
Conventional synthesis and manufacturing of thermoelectric materials is often tedious, time-intensive, and expensive with severe limitations in terms of resultant sample geometry and size. Recent work in additive manufacturing of thermoelectric semiconductors has identified current manufacturing limitations, including the need for post-processing that often leads to pore formation and decreased adhesion. Nevertheless, current work has not extensively studied how these methods alter thermoelectric transport. Specifically, we focus on a particle-laden ink extrusion printing process, which is conducted at room temperature, unlike the more commercially used powder bed fusion modality, and has proven successful with producing bulk Ni samples. Through altering printing parameters and sintering techniques, we study the microstructure of printed pure Ni and Bi, focusing specifically on densification, and observe the impact on thermoelectric transport behavior with the final goal of assessing whether or not particle-laden ink extrusion additive manufacturing is a viable technique for fabrication of thermoelectric devices.
3:40 PM Break
4:00 PM
Location-specific Fatigue Life Predictions in AM Parts Using Physics-based Models within an ICME Framework: Manisha Banker1; Ayman Salem1; Dan Satko1; Jan Kasprzak2; Nam Phan2; 1MRL Materials Resources LLC; 2Naval Air Systems Command
Conventional qualification of fatigue critical structures requires experimental fatigue life assessments supported by a large number of tests at coupon, subcomponent, component and system levels. A model-based fatigue life prediction method will be presented as a step towards model-based qualification of additively manufactured (AM) components. The physics-based fatigue life prediction model, developed by MRL, will be used to guide and/or replace experimental testing gradually for lower cost and rapid prediction of fatigue life in AM parts. Fracture mechanics principles are employed, capturing uncertainties and underlying physics in the deposited material as a function of processing and post-processing through location-specific digital identities and using extreme value statistics to predict corresponding fatigue strength and fatigue life under cyclic loading. With such an approach significant cost and time reductions are anticipated by the transferability of predictions from one AM part to another using MRL’s Integrated Computational Adaptive Additive Manufacturing (iCAAM) machine learning tools.
4:20 PM
Low Pressure Cold Spray Additive Manufacturing of Molds and Dies: Roman Maev1; Volf Leshchynsky1; Ahmed Elseddawy1; Emil Strumban1; John Wladarski1; 1IDIR
A cold spray process is a powder consolidation method that is capable of producing fully dense coating and bulk materials using accelerated particles that are deformed during high velocity impact onto a substrate. The Low Pressure Cold Spray process is seen as a viable method for additive manufacturing because of its high deposition rates and controllable spray jet. A process is developed to investigate the potential of the new low pressure cold spray additive manufacturing technique to make rebuilding of molds and dies. The thickness of a steel shell fabricated is about 3-10mm with the new method. This presentation presents information on the process, and details the various strategies employed during the die fabrication, structure and properties of steel layer and interface. Sintering is applied to utilize reactions between the particles and obtain steel layer structure with the high hardness.
4:40 PM
Microstructural and Electrochemical Properties of Additively Manufactured Alloys: Ali Raza1; Sohaib Khan2; Waseem Haider1; 1Central Michigan University; 2Islamic University of Madinah
Additive manufacturing or 3D printing of metals is emerging and rapidly growing manufacturing technique from prototyping to large production runs. This process involves the fusion of metal powder bed by selectively melting above the melting temperature and building layers on top of each other. The imminent advantages of producing complex geometries, unprecedented manufacturing flexibility, product customization and at the same time economically viable process makes it a potentially disruptive technology for different industrial applications. The huge interest of industries for adapting this technology also brought the attention of research community to work in this area with full potential. The changed melting and solidification dynamics during additive manufacturing, results into striking differences in the microstructural evolution in comparison to the one obtained through conventional casting process. This research will elucidate the microstructure, electrochemical response and the nature of passive oxide film formed on the wrought and additively manufactured metallic materials alloys.