Additive Manufacturing: Materials Design and Alloy Development II: Alloy Design-Functional Materials
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee, TMS: Integrated Computational Materials Engineering Committee
Program Organizers: Behrang Poorganji, Morf3d; James Saal, Citrine Informatics; Orlando Rios, University of Tennessee; Hunter Martin, HRL Laboratories LLC; Atieh Moridi, Cornell University
Thursday 2:00 PM
February 27, 2020
Room: 6F
Location: San Diego Convention Ctr
Session Chair: Behrang Poorganji, Morf3d
2:00 PM Cancelled
The Synthesis of Ti based Bulk Metallic Glass Alloys for Additive Manufacturing: Hwi-Jun Kim1; Yeon-Joo Lee1; Young-Sin Choi1; 1KITECH
Ti based bulk metallic glass materials exhibit very attractive properties such as high specific strength, high corrosion resistance and good biocompatibility. However, Bulk metallic alloys have limitations in manufacturing large-sized components three-dimensionally using conventional processes. In this study, we present the effect of crystalline fraction on microstructure and corrosion properties of cylindrical samples consolidated by additive manufacturing of Ti-BMG powders after alloy design of new BMG alloys with better solidification characteristics during additive manufacturing. Optimized Ti-BMG powders exhibited a nominal composition of Ti42.8Zr2.6Cu38.7Ni7.5Si1.4Sn5Ce1.3 La0.7 (at. %) and particle size distribution of 20 ∼ 63 ㎛. The crystalline fraction of samples was varied with additive manufacturing conditions leading to change of microstructure and corrosion properties. It was found that additive manufacturing provided advantage conditions for producing large-sized Ti-BMG components because of utilizing new BMG powder with better solidification characteristics.Keywords: Ti alloy; Bulk metallic glass; Crystallization; Corrosion resistance; Additive manufacturing
2:30 PM
Additive Manufacturing of Bulk Metallic Glass Composites with Improved Mechanical Properties: Shunyu Liu1; Abhijeet Dhiman1; Yung Shin1; Vikas Tomar1; Samuel Zhang1; 1Purdue University
This study demonstrates the in-situ synthesis of ZrCuNiAl bulk metallic glass composites with periodic amorphous-crystalline microstructure for improved ductility via laser additive process. The microstructure evolution mechanism was uncovered through simulating the thermal behavior using a computational model. By controlling the deposition parameters and composition, about 95.3 vol% amorphous phase and more than 50 vol% crystals were produced in fusion zone (FZ) and heat affected zone (HAZ), respectively. Nanoindentation tests were performed to study mechanical properties and deformation behaviors of pure amorphous and crystalline phases with a 700 nm indenter while a 100 µm indenter was utilized to capture the average properties in both zones. The depth-sensing indentation stress-strain data were accurately predicted with an improved iterative numerical algorithm using finite-element modeling, which predicted a yield stress of about 1.55 GPa and 0.52 GPa in FZ and HAZ, respectively and an equivalent indentation strain of more than 13%.
2:50 PM
Additive Manufacturing of Crack-free W-base Refractory Materials: Ian Mccue1; Michael Presley1; Michael Brupbacher1; Morgan Trexler1; 1Johns Hopkins University Applied Physics Lab
Tungsten has a number of exceptional properties – high density, melting point, thermal conductivity, stiffness, and strength – that make it an ideal candidate for high temperature structural applications. However, tungsten’s limited ductility at room temperature makes it challenging to forge and machine parts more complex than a rod or sheet. Formable W-base materials exist, but are either costly or have low operating temperatures. There is significant motivation to additively manufactured W parts, but printed components are riddled with cracks due to shrinkage and limited ductility during cooling. Here, we describe our work to develop W-base materials optimized for selective laser melting by exploring four processing strategies and combinations thereof: chemical (micro alloying), optical (absorbance), solidification rate (melt pool shape and volume), and grain refiners (controlled dopants). Our results demonstrate that even the most challenging metals can be produced additively, providing new potential applications of refractory metals.
3:10 PM
A Novel Titanium Alloy for Additively Manufactured Orthopaedic Implants: Enrique Alabort1; Alvaro De Diego2; Maria Vega Aguirre-Cebrián2; Daniel Barba2; Roger Reed3; 1OxMet Technologies; 2Universidad Politecnica de Madrid; 3University of Oxford
Most existing orthopaedic implants are inherently limited by the mismatch between the stiffness of metals and biological bone tissues. Moreover, most common biomedical alloys raise toxicological concerns. In this paper, alloy design is used to find optimal metallic titanium compositions which are bio-compatible, and which offer inherent lower modulus of elasticity for optimal bone compliance. The alloys were also optimised for additive manufacturing: alloys with low cracking susceptibility and tendency to form fine microstructures were isolated. An optimal alloy composition was then produced and manufactured by selective laser melting. Mechanical experiments on manufactured material under tension and compression reveal the stiffness and strength of the alloy. This work confirms the suitability of the titanium alloy to lower the stiffness of traditional biomedical alloys while being additively manufacturable and strong.
3:30 PM
Additive Manufacturing of Wear Resistant Metallic Glass Components for Space Exploration: Punnathat Bordeenithikasem1; Samad Firdosy1; Andre Pate1; John Paul Borgonia1; Douglas Hofmann1; 1NASA Jet Propulsion Laboratory
Metallic glasses and their associated composites have garnered interest in multiple spacecraft components due to their superb wear resistance. Metal additive manufacturing technologies provide the ability to fabricate complicated structures as well as cladding on existing surfaces. In this talk, studies involving powder bed fusion, directed energy deposition, and thermal spray additive manufacturing techniques used on metallic glass powder to create multiple microstructures of varying hardness and toughness will be discussed. Applications to produce components to resist lunar and mars regolith will be presented.
3:50 PM Break
4:05 PM Cancelled
Solidification Based Alloy Design for Metal Additive Manufacturing: Mark Easton1; Michael Benoit1; Duyao Zhang1; Dong Qiu1; David StJohn2; Milan Brandt1; 1RMIT University; 2University of Queensland
Typically alloys are developed for new processes and the next phase of metal additive manufacturing (MAM) will include strategies to maximise alloy performance by tailoring alloy chemistry. One of the advantages is that we already have a number of tools from our understanding of other solidification processes, such as casting and welding, which can guide research into new alloys. This talk will focus in on strategies for dealing with two of the more problematic issues in MAM: obtaining a fine grain structure and reducing the propensity to hot tearing. Background theory will be discussed, including what it is that makes MAM more challenging than other solidification processes. Some specific examples will be provided where alloy design has enabled the development of a fine-grained microstructure and where hot tearing susceptibility has been reduced.
4:35 PM
Material Design for Additive Manufacturing of Soft Magnetic Materials for Permanent Magnet Synchronous Machine Rotors: Lennart Tasche1; Florian Hengsbach1; Kai-Peter Hoyer1; Sebastian Magerkohl2; Stefan Urbanek3; Bernd Ponick4; Detmar Zimmer5; Mirko Schaper1; 1Paderborn University Department of Material Science; 2Paderborn University Chair of Design and Drive Technology; 3University of Hannover Institute for Drive Systems and Power Electronics; 4University of Hannover Institute for Drive Systems and Power Electronics ; 5Paderborn University
The processing of soft magnetic materials enabled the advent of additive manufacturing in electro-mechanical engineering. For some years, the possibilities and limits of various additive manufacturing processes for the production of electric drives have been explored. This research project focuses on the development of new materials for permanent magnet rotors produced by laser beam melting (LBM). Due to high cooling rates and the elimination of reshaping post-processing steps, FeSi alloys with a significantly higher silicon content up to 9 wt.% can be processed by means of LBM, which leads to improved soft magnetic properties. FeSi with varying silicon contents as well as FeCo alloys have been printed, annealed and characterized. Validation of the materials is done by mechanical testing as well as analyzing the microstructure using SEM (EDX & EBSD) and STEM, and subsequently by determining the permeability, coercive field strength and saturation flux density using toroidal cores.
4:55 PM
Novel Alloy Development Using Laser Directed Energy Deposition: Eric Heikkenen1; Sudarsanam Babu1; 1The University of Tennessee
Laser Directed Energy Deposition presents an exciting new opportunity for alloy development using in-situ powder mixing via multiple powder feed hoppers. This technique alloys for both novel alloy development and the fine-tuning of alloy compositions for additive manufacturing with unprecedented pace and reduced cost by completely circumventing the traditional alloy development cycle. Only a few powder compositions would be needed to create an incredibly wide range of resulting alloy compositions. Further advancement can be realized through the use of thermodynamic modeling to guide the process. As an example, silicon content in an aluminum alloy could be optimized precisely for additive manufacturing by using only two different powders. Alternatively, a stainless steel alloy could be optimized to limit delta ferrite formation upon rapid cooling by varying chromium and nickel content.
5:15 PM
Development of Prediction Tools for Incorporation of Cooling Rate Dependent Solute Drag Based Thermo-physical Properties in Additive Manufacturing: A Sensitivity Study: Deepankar Pal1; Kaisheng Wu2; Dave Conover1; 1ANSYS; 2Thermocalc
The non-linear and non-equilibrium conditions which exist during the solidification of metal melting additive technologies necessitate that a cooling rate dependent solute drag model be considered such that the thermophysical properties are appropriately addressed during additive thermal predictions. A sensitivity analysis with state transitions from powder to (liquid or vapor) to solid has been performed as a function of solver methodologies such as linear with Backward Euler formulation and non-linear with Backward Euler and Newton Raphson formulations with and without the effect of latent heats from phase transitions, due to the formation of liquid and vapor at relevant temperatures and state transitions. Further, both traditional non-linear and non-equilibrium, non-linear thermo-physical properties have been considered which provided with reasonable differences in melt pool dimensions and peak temperatures.These sensitivities in the light of newly established non-equilibrium solute partitioning workflow from Themocalc will be discussed during the talk.
5:35 PM
Towards an ICME Framework of Designing Post-process for Additively Manufactured Ti-6Al-4V: Shengyen Li1; Kirby Matthew1; James Sobotka1; 1Southwest Research Institute
Metal additive manufacturing produces net-shape products and generally introduces local features that need additional heat treatments to tailor the microstructure to meet performance requirements. This presentation discusses an ICME framework to predict microstructure evolution through the AM build process and subsequent heat-treatments. This framework accommodates Python libraries, materials data curation system, and hierarchical models to manage data and simulate phase transformation. We adopted a finite-element, heat-transfer model to simulate the AM build process, from which we export the temperature history for Scheil-Gulliver and a martensitic transformation models to simulate micro-segregation and estimate the stability of the BCC phase. Another hierarchical model is implemented with Thermo-Calc to simulate martensite to BCC/HCP transformation in a HIPing treatment. We will exercise this framework to design a heat treatment to improve the ductility of Ti-6Al-4V. This presentation will summarize the predicted microstructure, including phase fraction and grain size, to compare to the measured values.