Integrated Computational Materials Engineering Framework Research Articles

The effect of chemical vapor infiltration process parameters on flexural strength of porous α$\alpha$‐SiC: a numerical model

AbstractThe flexural strength variability of ‐ based ceramics at elevated temperatures creates the need for an Integrated Computational Materials Engineering (ICME) framework that relates the strength of a specimen directly to its manufacturing process. To create this ICME framework, a model must first be developed which establishes a relationship between the chemical vapor infiltration (CVI) process and parameters, the resulting mesoscale pores, and the overall macroscale flexural strength. Here, a nonlinear single‐pore model of CVI is developed used in conjunction with a four‐way coupled thermo‐mechanical damage model. The individual components of the model are tested and a sample system under a four‐point bending test is explored. Results indicate that specimens with an initial porosity greater than 30% require temperatures below 1273 K to maintain structural integrity, while those with initial porosities less than 30% are temperature‐independent, allowing for optimization of the CVI processing time without compromising strength.

ICME guided design of heat-treatable Zn-modified Al–Mg alloys

Currently, there is a tendency towards breaking through conventional 5000 series aluminum alloys framework and designing heat-treatable Al–Mg based alloys with the improved mechanical properties. Here, based on a small amount of experimental work and our previously developed Integrated Computational Materials Engineering (ICME) framework, the authors systematically and efficiently optimize the Zn content and two-step aging treatment process in the heat-treatable Al–Mg–Zn alloys. It is found that the addition of 3.0 wt.% Zn can lower the nucleation activation energy, promote the precipitation of the T phase, and thus enhance and accelerate the age-hardening response of Al–Mg–Zn alloys. Different from the single-step aging process, the pre-aging treatment leads to a large number of fine and dispersive T precipitates due to the precipitation of numerous, stable and dispersive precursors. Further, we optimized two-stage aging treatment for the Al-5.1Mg-3.0Zn alloy which enables the peak-aged yield strength to increase by 21.1% as compared to that in the single-step aging process. This research presents an efficient strategy to design new-generation aluminum alloys via combining the key experimental data and an ICME framework.

ICME Framework for Simulation of Microstructure and Property Evolution During Gas Metal Arc Welding in DP980 Steel

An integrated computational materials engineering (ICME)-based workflow was adopted for the study of microstructure and property evolution at the heat-affected zone (HAZ) of gas metal arc-welded DP980 steel. The macroscale simulation of the welding process was performed with finite element method (FEM) implemented in Simufact Welding® software and was experimentally validated. The time–temperature profile at HAZ obtained from FEM simulation was physically simulated using Gleeble 3800® thermo-mechanical simulator with a dilatometer attachment. The resulting phase transformations and microstructure were studied experimentally. The austenite-to-ferrite and austenite-to-bainite transformations during cooling at HAZ were simulated using the Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation implemented in JMatPro® software and with phase-field modeling implemented in Micress® software. The phase fractions and the phase transformation kinetics simulated by phase-field method agreed well with experiments. A single scaling factor introduced in JMatPro® software minimized the deviation between calculations and experiments. Asymptotic homogenization implemented in Homat® software was used to calculate the effective macroscale thermo-elastic properties from the phase-field simulated microstructure. FEM-based virtual uniaxial tensile test with Abaqus® software was used to calculate the effective macroscale flow curves from the phase-field simulated microstructure. The flow curve from virtual test simulation showed good agreement with the flow curve obtained with tensile test in Gleeble®. An ICME-based vertical integration workflow in two stages is proposed. With this ICME workflow, effective properties at the macroscale could be obtained by taking microstructure morphology and orientation into consideration.

Advanced Titanium Alloy Fatigue Modeling

A summar y of the final progress achieved in two Metals Affordability Initiative (MAI) programs (RR-12 and RR-13) that were funded by the US Air Force to develop the necessary integrated computational materials engineering (ICME) framework, knowledge, and supporting database to model and predict location-specific fatigue properties across the entire titanium supply chain is presented. Validation of this ICME framework which allows for the prediction of location specific low cycle fatigue (LCF) and high cycle fatigue (HCF) behavior on complex production components in electro-polished and shot peened surface conditions will be presented. In addition, validation of a new shot peening capability embedded with the commercial software package DEFORM™ will be presented.

Integrated Computational Materials Engineering: Extending from Design to Supply Management

Integrated Computational Materials Engineering (ICME) has significantly matured during the last one decade, in terms of formal definition, thriving technical community, framework for workflow, textbooks, academic curriculum as well as few examples of their maturity into products. However, hitherto the scope of ICME has been limited to simultaneous optimization of design, materials and manufacturing processes for developing a robust and optimal product. Unfortunately, in this VUCA world (volatile, uncertain, complex and ambiguous), there is dynamic complexity of external influences, such as volatility in commodity prices with time, which renders the optimal choice determined by the ICME framework redundant within a short duration. The complexity of the problem further increases as different commodity prices fluctuate in unsynchronized manner at different periods of time with different amplitudes. The 3 × increase in cobalt price in 2018, spikes in nickel price in 2008 and ferrochromium in 2006 are clear examples of such unforeseen asymmetric distortions of commodity prices. Consequently, for a specific component, if an ICME approach is used to simultaneously optimize materials grade, design and manufacturing process, the selected preferred grade due to their superior cost–performance attributes at that specific time may not remain so in the future. In the present work, the ICME framework has been expanded by including dynamic ranking of material types and grades to manage such asymmetric commodity price volatility with time. The effectiveness of this approach has been illustrated with use case of an axle shaft with multiple grade optionality. In this example, it has been demonstrated that by exploration of multi-optionality at the initial design stage, the preferred grade ranking changes with commodity price asymmetric volatility. Furthermore, a predictive model has been developed to develop future material ranking strategy for a specific component in an OEM.

ICME guided property design: Room temperature hardness in cemented carbides

The potential change in EU regulations may affect the traditional W-C-Co based cemented carbides industry and a methodology is required to accelerate the materials development with alternative binders. This work presents the ICME (Integrated Computational Materials Engineering) framework and the improved models that will enable tailor-made materials design of cemented carbides. The cemented carbide hardness is one of the key properties of the composites and here its close relation to the binder composition is in focus. Modeling the influence of alternative binder materials on the hardness of cemented carbides offers a way to optimize the composite properties of prospective binder candidates virtually, thereby reducing the development time and costs drastically compared to a classical trial-and-error method. The outline of a genetic algorithm is presented and the integration of the required models and tools, that are, or will become, available within this ICME framework, are presented.

An ICME Framework for Incorporating Bulk Residual Stresses in Rotor Component Design

Integrated Computational Materials Engineering (ICME) is an emerging discipline that aims to integrate computational materials science tools into a holistic system that can accelerate materials development, transform the engineering design optimization process, and unify design and manufacturing. A team of aerospace Original Equipment Manufacturers (OEMs) and suppliers have executed a critical program to address the United States Air Force (USAF) funded Foundational Engineering Problem (FEP) on residual stress within nickel-base superalloy components. This program was aimed at establishing methods to link predictive tools to component design functions and product realization activities with industry-wide standardized protocols. The multi-disciplinary approach links supplier and OEM materials and process models with structural analysis tools to enable manufacturing parameter selection based on disk design criteria. By linking analytical tools between the supplier and OEM, process parameters may be optimized for reduced scrap, while optimizing disk designs for design requirements. A significant challenge to doing this is qualifying and integrating sources of variation in the materials and process models with design and structural analysis tools. This paper reviews ICME infrastructure tools and methods that were used to demonstrate and validate linked residual stress-based materials and manufacturing model capabilities with design activities to achieve an optimized final component. This work was funded by the United States Air Force through the Metals Affordability Initiative (MAI).

An ICME Framework for Design of Stainless Steel for Sintering

Recent progress in the development of integrated computational materials engineering (ICME) models offers new capabilities to deal with the challenge of designing multi-component alloys. In this study, a new type of computational method for efficient design of sintered stainless steel alloys, optimized for manufacturability (sintering) as well for performance, is presented. Development of the design method follows the materials systems approach that integrates processing, structure, and property relations during metal injection molding (MIM). It includes a multi-objective genetic algorithm (GA) to optimize alloy composition with the aim of improving the sintering as well as performance-related properties. To achieve this, the GA is coupled with computational thermodynamics and predictive analytical models. Thermodynamic simulations, based on the calculation of phase diagram CALPHAD method, are used to establish constraints through phase stability at equilibrium and calculate the diffusivity that determines the sintering behavior of the alloy. In addition, an advanced predictive model is used to determine solution strengthening. To demonstrate the capability of our method, a design exercise for austenitic stainless steel is presented. New alloys which are optimized for improved sinterability, yield strength, corrosion resistance, and cost are compared to 316L, a commercially available austenitic steel that is widely produced by MIM.

Integrated Modeling of Carburizing-Quenching-Tempering of Steel Gears for an ICME Framework

In order to leverage the concept of integrated computational materials engineering (ICME) for manufacturing of high-performance automotive transmission components such as steel gears, it is important to bring a closer collaboration between geometrical design, material selection, and manufacturing design stages for these components. This can be achieved by making the manufacturers aware of the implications of the decisions taken during each of these stages on material and its underlying microstructure. In order to facilitate this, it is necessary to model the evolution of the microstructure in the process-chain and its resultant properties. With this view, the current work focusses on development of an integrated modeling scheme of carburizing, quenching, and tempering processes using chemical composition-dependent, microstructure-based models intended to be used in an ICME framework for steel gear manufacturing. The individual process models are implemented in the commercial FEM suite ABAQUS™, with essential microstructure physics incorporated via user-subroutines. The individual process-models and their sequential integration are validated against experimental case-studies from literature. After validation, the integrated modeling scheme is automated by writing appropriate pre-processing and post-processing wrapper scripts, leading to the development of an independent manufacturing module that can be used in an ICME workflow. Finally, the utility of this module is demonstrated by using it for the exploration of the manufacturing process design and material selection scenarios for the production of a typical spur gear.

Towards rapid qualification of powder-bed laser additively manufactured parts

Qualification of aerospace components is a long and costly process involving material properties, material specifications, manufacturing process, and design among others. Reducing qualification time and cost while maintaining safety offers a large economic advantage and enables faster response to the market demands. In 2012, DARPA established the Open Manufacturing program, a project to develop an integrated computational materials engineering (ICME) framework aimed at rapid qualification. Rapid qualification requires the integration of several technologies: materials, process, design, models, monitoring and control, non-destructive evaluation (NDE), testing, among others. A probabilistic design approach is adopted in the rapid qualification process to enable the integration of these technologies into a single risk-based function to optimize the design process. This approach directs the efforts to those areas that play the most important roles, potentially reducing specimen testing that will be required to develop material databases and design limits. New tests also will be required to validate and verify the ICME framework and develop a better understanding of the processing-microstructure-property relation and associated variability of the processing conditions. The probabilistic design approach is demonstrated for the rapid qualification of an actual aircraft engine component constructed via the powder-bed additive manufacturing process. This paper summarizes the probabilistic rapid qualification design approach and its application to this novel manufacturing process with the goal of reducing the overall qualification process time by 40 % and qualification process cost by 20 %.

Computational Thermodynamics and Kinetics-Based ICME Framework for High-Temperature Shape Memory Alloys

Over the last decade, considerable interest in the development of High-Temperature Shape Memory Alloys (HTSMAs) for solid-state actuation has increased dramatically as key applications in the aerospace and automotive industry demand actuation temperatures well above those of conventional SMAs. Most of the research to date has focused on establishing the (forward) connections between chemistry, processing, (micro)structure, properties, and performance. Much less work has been dedicated to the development of frameworks capable of addressing the inverse problem of establishing necessary chemistry and processing schedules to achieve specific performance goals. Integrated Computational Materials Engineering (ICME) has emerged as a powerful framework to address this problem, although it has yet to be applied to the development of HTSMAs. In this paper, the contributions of computational thermodynamics and kinetics to ICME of HTSMAs are described. Some representative examples of the use of computational thermodynamics and kinetics to understand the phase stability and microstructural evolution in HTSMAs are discussed. Some very recent efforts at combining both to assist in the design of HTSMAs and limitations to the full implementation of ICME frameworks for HTSMA development are presented.

Material design and development: From classical thermodynamics to CALPHAD and ICME approaches

This paper presents an overview and examples of material design and development using (1) classical thermodynamics; (2) CALPHAD (calculation of phase diagrams) modeling; and (3) Integrated Computational Materials Engineering (ICME) approaches. Although the examples are given in lightweight aluminum and magnesium alloys for structural applications, the fundamental methodology and modeling principles are applicable to all materials and engineering applications. The examples in this paper have demonstrated the effectiveness and limitations of classical thermodynamics in solving specific problems (such as nucleation during solidification and solid-state precipitation in aluminum alloys). Computational thermodynamics and CALPHAD modeling, when combined with critical experimental validation, have been used to guide the selection and design of new magnesium alloys for elevated-temperature applications. The future of material design and development will be based on a holistic ICME approach. However, key challenges exist in many aspects of ICME framework, such as the lack of diffusion/mobility databases for many materials systems, limitation of current microstructural modeling capability and integration tools for simulation codes of different length scales.