QuesTek's Materials by Design® approach combines the fundamentals of Integrated Computational Materials Engineering (ICME) with our proprietary materials property databases, mechanistic models, characterization tools, and complex materials-specific software. This method has proven successful in the design of four ultra high performance Ferrium steels that have been licensed to Carpenter Technology, as well as new alloys based on aluminum, cobalt, copper, molybdenum, nickel, niobium, titanium and tungsten. We have worked on >100 projects for government and private industry to develop and optimize new materials and alloys, some examples can be seen here.
Materials by Design
QuesTek’s Materials by Design methodology embodies the concept that new alloys and other materials can be designed using simulation tools in order to meet specific property design goals.
We minimize costly and time-consuming experimentation by coupling physics-based, computationally-enabled expertise and design tools with advanced characterization techniques in order to rapidly focus on a few iterative prototypes that are scaled up.
Our design methodology has been applied to develop entirely new alloys, and to optimize the composition and thermal processing of legacy alloys to improve certain properties or reduce cost.
Materials as a System: System Design Chart
We design new materials by analyzing them as a system of inter-connected subsystems which address user-defined performance objectives, and which are mapped to specific property targets (determined by the alloy microstructure), which are in turn defined by material chemistry and processing paths.
We create a “System Design Chart” that outlines the major processing – microstructure – properties – performance relationships for a given material system which are used to determine design goals and address input from our client (i.e., “Voice of the Customer”).
As we work through our proven stage-gate design and development process to design new materials, we identify multiple levels of material microstructural hierarchy and link them to corresponding properties and processing steps.
Shown below is a System Design Chart for QuesTek’s Ferrium C64 (developed under a contract from US Navy Solicitation Topic#N05-T006):
Fundamental Materials Parameters
QuesTek builds and maintains our own proprietary fundamental material parameter databases that accurately define material microstructure and properties at various length scales, such as:
- Bulk (chemical and elastic) – e.g., ThermoCalc or first-principles
- Surface – e.g., surface energy or grain boundary energy segregation
- Bulk – e.g., atomic mobility and diffusion (using DICTRA)
- Interfacial Diffusion and Mobility
- Electrical and Thermal Conductivity
- Elastic Modulus
- Molar Volume
We integrate material parameter databases and models from a variety of sources such as: our own proprietary data and analysis; doctoral thesis research by individuals; open scientific papers; and existing parameter databases and models in CALPHAD, first principle, and other commercially-available software.
Microstructure and Predictive Property Models
We leverage the most recent scientific principles and experimental data available in order to develop or refine our own proprietary, mechanistic, physics-based models and tools, as well as models or conceptual frameworks available in the open literature.
Inputting the chemical composition and thermal processing, these mechanistic models can predict fundamental material properties, allowing QuesTek to design new alloys and other materials to meet specific property goals, such as:
|- Tensile strength||- Creep|
|- Fatigue strength||- Coefficient of thermal expansion (CTE)|
|- Fracture toughness||- Electrical and thermal conductivity|
|- Ductile-to-brittle transition temperature (DBTT)||- Thermal stability|
|- General corrosion resistance||- Martensite start (Ms) temperature|
|- Stress corrosion cracking (SCC) resistance||- Solidification segregation|
Our models can also be used to evaluate and optimize material processing as well as material compositions, such as:
|- Solidification/casting||- Heat treatment including carburization|
|- Homogenization and annealing temperatures||- Cold working|
|- Forging temperatures|
- Describe detailed spatial and time-dependent hierarchies
- Incorporate multi-component thermodynamics and physical kinetics models as their underlying basis
- Are designed to allow for substantial variation over a wide range of scales and compositions, in order to drive robust material designs that consider a spectrum of usage factors
- Can be extended to new material systems or new modeling goals with minimal effort
Hierarchy of Design Models
We design specific material microstructural evolution to occur at a wide spectrum of length scales (nanometer scale and beyond).
By designing for full-scale production effects up-front in our stage gate design and development process and by using advanced predictive tools such as Accelerated Insertion of Materials (AIM), we rapidly accelerate development timelines, develop robust material designs that allow for variation in processing effects at full-scale production, and reduce development risks for our clients.
The following figure illustrates some of the representative models, instruments and tools that we use at various length scales in order to design and characterize materials.
During the materials design process, QuesTek uses a wide range of advanced instruments and other techniques to produce, characterize and analyze prototype materials that we design and develop, as a feedback loop to refine our databases, mechanistic models, and material designs.
More information on the equipment and characterization tools that we use can be found on our Facilities and Resources page.
QuesTek has made significant investments to create a unique computational materials design platform, and has also developed proprietary design tools and material databases in order to drive its materials modeling, design and development efforts.
Our computational resources include engineering workstations with ThermoCalc and DICTRA thermochemical and kinetic software systems, along our proprietary software platform, PrecipiCalc® software.
We integrate it with rest of our Materials by Design technology and stage gate design and development process in order to rapidly explore, evaluate, invent and optimize material designs.
- Is a sophisticated computer program that we developed and use to calculate three-dimensional, multi-particle diffusive precipitation kinetics of multiple phases.
- Can rapidly analyze precipitation effects in materials.
- Incorporates the Thermo-Calc Advanced Programming Interface (TCAPI) and adopts multicomponent thermodynamics and mobility (based on the CALPHAD methodology) in its precipitation models.
- Allows for realistic and mechanistic modeling on nucleation, growth and coarsening.
PrecipiCalc is also used by other industry leaders (under licensing agreements from us), but we remain the leading experts in its application and customization.
PrecipiCalc is a central microstructural engine used in Accelerated Insertion of Materials (AIM) methodology.
Typical inputs to PrecipiCalc include:
- Physical quantities such as material compositions, bulk thermodynamics and mobility (TDB files), interfacial properties (such as surface energy and interfacial dissipation), and lattice properties (such as molar volume).
- Thermal cycle, or temperature profile, which defines the thermal history of the material being processed. The thermal cycle can be constant (isothermal), linear cooling (quench), or complicated nonlinear and non-monotonic heat treatments (such as multi-step tempering).
Typical outputs include the time evolution of:
- Precipitate microstructure - precipitate size distribution, number density and volume fraction, which can be used to construct TTT/CCT diagrams.
- Compositions of matrix and precipitate.
- Driving forces, nucleation rates and critical radii.
QuesTek has applied PrecipiCalc software to computationally design materials and optimize processes for a wide range of material systems, including:
- Carbide/nitride/intermetallic grain refiners (in weld HAZ) and strengthening dispersions during tempering in steels.
- Primary inclusion and strengthening phases in Al-based alloys.
- γ’, carbides and borides in Ni-based superalloys.
- Heusler phase in NiTi-based shape memory alloys.
We have also developed and use a proprietary software platform and system that provides an interface to efficiently integrate our own models and software with other software such as Engineous Software iSIGHT PRO (a design integration software that automates the manual design process) and Scientific Forming Technology Corporation (SFTC) DEFORM-3D HT finite element method (FEM) software (used for calculating the thermal and mechanical responses of a component undergoing a specified heat treatment).
- Computational Materials Design and Engineering
A detailed review of the computational materials design methodology and its application to property- and performance-driven materials engineering - Material Science and Technology, Vol. 25 No. 4, 2009
- PrecipiCalc® Brochure
A detailed technical description of the PrecipiCalc® software.
- ASM TMS Annual Symposium 2007
QuesTek's Computational Materials Design Presentation at
- Materials Science & Technology 2009
An in-depth overview of QuesTek's computational materials design methodology, principles and examples
- QuesTek's Use of Thermo-Calc & DICTRA for Materials by Design at Thermo-Calc Seminar 6Apr11