CALPHAD in Patents

We warmly invite inventors, researchers, and organizations who have utilized the CALPHAD method in the development of patented technologies to share their work on this page. Whether you’ve employed tools such as Thermo-Calc, Pandat, JMatPro, FactSage, OpenCalphad, PyCalphad, or other CALPHAD-based software to guide alloy design, process optimization, or materials innovation, we welcome your contributions.

If you hold one or more patents where CALPHAD played a meaningful role, we encourage you to submit a brief summary highlighting:

The patent number and title
The role of CALPHAD in your invention
The specific CALPHAD tools used and their purpose in the design process

This initiative aims to showcase how computational thermodynamics contributes to real-world innovation and intellectual property across industries. Contributions will help build a growing community resource at the intersection of CALPHAD and patentable invention, highlighting the practical impact of these powerful tools in modern materials development.

To submit your summary or inquire further, please contact us at calphad@gmail.com.

Curated List of CALPHAD Patents

Articles Fabricated from Cold-Worked and Case-Hardened Essentially Co-free Stainless Steel Alloys and Methods of Fabricating Thereof

Patent Number: US 12,188,112 B2
Inventors: Stephane Alexis Jacques Forsik, Mario Epler, Alojz Kajinic, Gaurav Lalwani, Logan Smoth
Date of Patent: January 7, 2025

US 12,188,112 B2 discloses corrosion-resistant, essentially cobalt-free stainless steel alloys that can be cold-worked and subsequently case-hardened to form high-performance articles with enhanced mechanical strength, surface hardness, and wear resistance. The invention is particularly relevant for articulating orthopedic applications, where cobalt is preferably avoided due to toxicity, regulatory, or supply concerns. The process involves selecting alloy chemistries that maintain phase stability and mechanical properties during thermochemical treatments. Computational thermodynamics was employed to guide the alloy design by predicting phase equilibria, solute partitioning, and the effects of nitrogen, carbon, and boron during case hardening. These simulations helped avoid unwanted phase formation and optimize austenite stability, ensuring compatibility with low-temperature nitriding, carburizing, carbonitriding, or boriding processes.

New Titanium Aluminide Alloys and Methods for Making the Same

Patent Application Number: WO 2020/086263 A1
Inventors: Alojz Kajinic, Xuan Nguyen-Dinh
Date of Patent Application: April 30, 2020

WO 2020/086263 A1 relates to the incorporation of boron and silicon into the Ti-48Al-2Cr-2Nb gamma titanium aluminide alloy (originally patented by General Electric Company in 1989) to enhance laser-based additive manufacturability and room-temperature ductility. The invention introduces a modified Ti-48Al-2Cr-2Nb composition containing sufficient amounts of boron and silicon to enable (a) the production of crack-free additively manufactured components and/or (b) crack-free repair of existing titanium aluminide alloy parts, such as legacy Ti-48Al-2Cr-2Nb components. High-throughput CALPHAD-based simulations using Thermo-Calc, TCTI (Ti/TiAl thermodynamic database), and TC-Python SDK were employed to guide alloy design by predicting solidification paths, phase fractions, and the stability of key phases including γ-TiAl, α₂-Ti₃Al, β-Ti, and boride precipitates.

Titanium Aluminide Alloys and Titanium Aluminide Alloy Products and Methods for Making the Same

Patent Application Number: WO 2019/191450 A1
Inventors: Alojz Kajinic, Xuan Nguyen-Dinh
Date of Patent Application: October 3, 2019

WO 2019/191450 A1 describes titanium aluminide (TiAl) alloys tailored for high-temperature applications in the automotive and aerospace industries. The invention emphasizes alloy compositions optimized for improved laser-based additive manufacturability, castability, resistance to hot cracking, room-temperature ductility, tensile yield strength, and creep resistance. Thermo-Calc software, coupled with TCTI (Ti/TiAl thermodynamic database) and TC-Python SDK, enabled high-throughput simulations to guide alloy design by controlling the solidification path and the volume fractions and stability of key phases such as γ-TiAl, α₂-Ti₃Al, β-Ti, and titanium borides, while also assessing the effects of minor additions like boron, tantalum, tungsten, and molybdenum. The resulting alloys exhibit significantly improved laser-based additive manufacturability and room-temperature ductility compared to conventional TiAl intermetallic alloys.

Creep-Resistant, Cobalt-Containing Alloys for High Temperature, Liquid-Salt Heat

Patent Number: US 10,017,842 B2
Inventors: David E. Holcomb, Govindarajan Muralidharan, Dane F. Wilson
Date of Patent: July 10, 2018

US 10,017,842 B2 discloses a new class of iron-free, solid-solution-strengthened nickel-based alloys tailored for high-temperature service in molten salt heat exchanger systems, particularly in fluoride-salt-cooled high-temperature reactors (FHRs) and concentrated solar power systems. These alloys offer enhanced creep resistance, oxidation resistance, and corrosion resistance at temperatures greater than 850 °C, outperforming conventional materials like Hastelloy N. JMatPro was used to guide alloy development, enabling predictions of equilibrium phase fractions and the avoidance of brittle intermetallics. This computational approach informed compositional limits for cobalt, chromium, molybdenum, tantalum, tungsten, and minor elements to achieve long-term microstructural stability, mechanical strength, and low corrosion rates in FLiNaK molten salt, a eutectic mixture of lithium fluoride (LiF), sodium fluoride (NaF), and potassium fluoride (KF).

Low-Cost, High-Strength Fe-Ni-Cr Alloys for High Temperature Exhaust Valve Applications

Patent Number: US 9,752,468 B2
Inventor: Govindarajan Muralidharan
Date of Patent: September 5, 2017

US 9,752,468 B2 describes a new class of low-cost, high-strength iron-nickel-chromium alloys designed for use in high-temperature automotive and diesel engine exhaust valves operating between 870 °C and 1000 °C. The alloys achieve high strength and creep resistance through a carefully engineered microstructure dominated by gamma prime precipitates and MC-type carbides, while minimizing the use of costly elements like cobalt. The design strategy involved tailoring the composition to control lattice misfit, antiphase boundary energy, precipitate volume fraction, and coarsening resistance. To guide this development, the inventor used JMatPro, a CALPHAD-based thermodynamic simulation tool, to predict phase equilibria, gamma prime fraction, and thermodynamic stability for various alloy compositions. These simulations ensured optimal strengthening at elevated temperatures and validated the performance potential of several candidate alloys relative to commercial standards like X750, Nimonic 80A, IN 751, Nimonic 90, Waspaloy, and Rene 41.

High Strength Alloys for High Temperature Service in Liquid-Salt Cooled Energy Systems

Patent Number: US 9,540,714 B2
Inventors: David E. Holcomb, Govindarajan Muralidharan, Dane F. Wilson
Date of Patent: January 10, 2017

US 9,540,714 B2 describes a class of essentially cobalt-free, nickel-based superalloys designed for high-strength performance in corrosive high-temperature environments, such as fluoride-salt-cooled high-temperature reactors (FHRs). The alloys are strengthened primarily through gamma-prime precipitation along with solid-solution strengthening. A small amount of carbides is also present to prevent grain boundary sliding. The inventive compositions achieve a unique balance between mechanical properties and fluoride salt corrosion resistance. JMatPro software was used as the CALPHAD-based computational thermodynamics tool to calculate phase equilibria and evaluate the presence and stability of gamma prime and carbide phases across multiple compositions. The modeling ensured avoidance of brittle intermetallic phases and guided the tailoring of aluminum, titanium, niobium, tantalum, and tungsten content to achieve the target gamma-prime fractions while maintaining corrosion susceptibility indices within an optimal range.

Wear Resistant High Temperature Alloy

Patent Number: US 7,651,575 B2
Inventors: Maria K. Sawford, Shubhayu Sinharoy, Sundaram L. Narasimhan, Alojz Kajinic, Andrzej L. Wojcieszynski, Jeryl K. Wright
Date of Patent: January 26, 2010

US 7,651,575 B2 discloses a iron-nickel-based alloy with enhanced wear resistance and high-temperature mechanical properties tailored for engine components such as exhaust valves. The alloy achieves a balanced composition of carbon, chromium, nickel, aluminum, titanium, and niobium/tantalum, optimized to produce a dispersion of primary MC-type carbides and a gamma-prime strengthening phase. These microstructural features contribute to improved hardness, hot strength, fatigue resistance, oxidation resistance, and pin abrasion resistance. The alloy offers comparable or superior performance to nickel-based superalloys, without requiring expensive cobalt-based hardfacing. The inventors used Thermo-Calc CALPHAD modeling to guide alloy design. This enabled the prediction of phase stability and carbide volume fractions under processing conditions, which in turn allowed for fine-tuning of the composition for optimal mechanical and thermal performance.

Cold-Work Tool Steel Article

Patent Number: US 7,615,123 B2
Inventors: Alojz Kajinic, Andrzej L. Wojcieszynski
Date of Patent: November 10, 2009

US 7,615,123 B2 discloses a cold-work tool steel article produced via powder metallurgy (PM) using hot isostatic pressing (HIP) of nitrogen atomized, prealloyed powders. The key innovation is the addition of niobium, which enhances the driving force for MC-type carbide formation, leading to a finer and more uniform dispersion of hard niobium–vanadium-rich carbides. This refined carbide distribution significantly improves impact toughness and bend fracture strength compared to conventional PM and ingot-cast tool steels. CALPHAD modeling using Thermo-Calc and the TCFE3 database was employed to predict the phase behavior and optimize alloy chemistry. The resulting steel achieves excellent toughness without sacrificing wear resistance, demonstrating its suitability for demanding cold-work applications.

Coherent Nanodispersion-Strengthened Shape-Memory Alloys

Patent Number: US 7,316,753 B2
Inventors: Jin-Won Jung, Gregory B. Olson
Date of Patent: January 8, 2008

US 7,316,753 B2 discloses a class of high-strength, low-hysteresis TiNi-based shape-memory alloys (SMAs) strengthened by coherent, low-misfit nanoscale precipitates, such as Heusler-type L2₁ phases. These precipitates enhance cyclic life and output force, crucial for demanding applications like self-expanding medical stents and microactuators. The alloy design is based on the systematic application of the CALPHAD method modeling using Thermo-Calc and a custom thermodynamic database for the Ti-Ni-Al-Zr system. CALPHAD calculations guided the selection of alloying elements (Al, Zr, Hf, Pd, Pt) to reduce lattice misfit (<2.5%) and optimize phase stability and transformation temperatures. Experiments validated predictions, demonstrating compressive strengths exceeding 2000 MPa and transformation temperatures tunable across a wide range.

Corrosion and Wear Resistant Alloy

Patent Number: US 7,288,157 B2
Inventors: Alojz Kajinic, Andrzej L. Wojcieszynski, Maria K. Sawford
Date of Patent: October 30, 2007

US 7,288,157 B2 discloses a powder metallurgy martensitic tool steel alloy that provides an optimized balance of corrosion resistance, wear resistance, and mechanical properties. The invention focuses on alloy design that includes high levels of chromium, vanadium, and especially niobium, which leads to the formation of hard, niobium-rich MC-type carbides. These carbides do not tie up as much chromium, thereby increasing the amount of “free” chromium in the matrix, improving corrosion resistance. The CALPHAD method was used to design and verify this behavior: specifically, Thermo-Calc software coupled with the TCFE3 thermodynamic database was used to predict the composition of the austenitic matrix and the primary carbides at different heat treatment temperatures. This computational thermodynamics approach enabled the optimization of the alloy chemistry to achieve both superior pitting resistance and wear properties.