Fraunhofer Institute for Mechanics of Materials IWMHydrogen engines are considered a promising alternative for heavy-duty off-road machinery, but hydrogen can damage metallic materials inside the engine, especially under cyclic loading. The PoWer project systematically investigates how engine components fatigue under real hydrogen atmospheres and develops robust design strategies for the commercial vehicle sector. Using innovative hollow-specimen and micro-specimen techniques, local material damage under high-pressure hydrogen is being quantified for the first time. The results provide designers and engine developers with reliable data for the safe design of H₂ powertrains. This paves the way for reliable, zero-emission heavy-duty machinery in construction, agriculture, and mining.
Potential of hydrogen engines for efficient and robust off-road applications
Ongoing research project
Project description
Market Demand and Challenge
The decarbonization of heavy off-road machinery—construction equipment, agricultural machinery, and mining vehicles—is one of the greatest challenges of the mobility transition. Battery-electric powertrains face limitations here due to high energy requirements and long operating times. Hydrogen internal combustion engines offer a realistic alternative: they utilize existing engine architectures, deliver high power density, and enable emission-free operation. However, hydrogen reacts aggressively with metallic materials. Atomic hydrogen diffuses into the metal structure, accumulates at stress concentrations, and can lead to premature failure under cyclic loading—such as that caused by start-stop cycles in engine components. For the commercial vehicle sector, with its high robustness requirements, reliable material data under realistic operating conditions has been lacking until now.
Contribution of the Project
The PoWer joint research project systematically addresses this gap. It investigates the potential of hydrogen engines specifically for off-road use and develops material data and design guidelines that enable safe and durable construction. Fraunhofer IWM contributes its expertise in mechanical testing under real high-pressure hydrogen atmospheres. By comparing electrolytic and gaseous hydrogen loading, practical testing methods are being developed that will shorten development times and reduce costs in the future. The results are directly relevant to engine manufacturers, suppliers of valves, cylinder heads, and injection components, as well as to the standardization of hydrogen-compatible materials. In this way, PoWer makes a significant contribution to Europe’s technological sovereignty in zero-emission heavy-duty propulsion systems and supports climate goals in the transportation sector.
Fraunhofer IWM’s work packages in the project:
Material testing under real hydrogen atmospheres:
Fraunhofer IWM conducts comprehensive material and fatigue tests in high-pressure hydrogen gas. At the core of these efforts are low-cycle fatigue (LCF) tests and slow-strain-rate tensile (SSRT) tests on various material classes using innovative hollow specimen technology. These tests provide fatigue data under conditions that are as close to reality as possible, such as those found inside hydrogen engines. Fraunhofer IWM’s particular strength lies in mechanical testing under a controlled high-pressure hydrogen atmosphere—an expertise currently unavailable elsewhere within the consortium.
Hydrogen Analysis and Microsample Investigations:
A second focus is on high-resolution hydrogen analysis using carrier gas hot extraction (TGH) and thermal desorption spectroscopy (TDS). These methods are used to determine hydrogen concentrations and binding energies in the materials under investigation—including components (such as valves) that have already been in service. Using micro-sample techniques, the IWM can also characterize local material properties in critical component zones that would not be accessible with conventional macroscopic samples.
Method Development and Project Support:
The overarching goal of the IWM’s work is to develop a standardized testing methodology for material fatigue under the influence of hydrogen. In particular, the research systematically determines when the experimentally simpler electrolytic loading is sufficient as a conservative approximation and when the more complex pressurized hydrogen testing is indispensable. This foundational methodological work lays the groundwork for future standards and industrial qualification procedures.
Based on the project results, Fraunhofer IWM can offer industrial companies the following research and development services:
Fatigue testing in high-pressure hydrogen for engine components
LCF and SSRT testing on company-specific materials in a real hydrogen atmosphere up to 300 bar, under conditions that correspond to the actual operating conditions of hydrogen-carrying components.
Your benefits:
- Reliable service life data as the basis for a safe and weight-optimized component design
- Avoidance of overly conservative safety factors through material- and application-specific measurement data
- Early detection of damage risks and prevention of costly in-service failures
Local material characterization using micro-sample technology in a hydrogen micro-autoclave
Extraction and characterization of microsamples from critical component areas—such as machined edge zones, weld seams, or coating interfaces—under hydrogen conditions.
Your benefits:
- First-time determination of the actual local stress capacity in failure-relevant component areas—rather than averaged volume properties
- A sound basis for targeted process optimization of machining parameters and heat treatments
- Increased hydrogen resistance based on real component conditions
Hydrogen analysis and trap characterization for material selection
Combined TGH/TDS analyses for the quantitative determination of hydrogen content and binding energies in metallic materials.
Your benefits:
- Systematic evaluation of which alloys and microstructural states effectively trap hydrogen in harmless traps and which are susceptible to hydrogen-induced damage
- Acceleration of material selection and qualification for H₂ applications
- A robust data foundation for certification procedures and compliance with standards
Test Method Consulting: Electrolytic vs. Pressurized Hydrogen Loading
Based on validated project results, Fraunhofer IWM advises companies on which test method is suitable for the respective material and application and when the more complex pressurized hydrogen test is required.
Your benefits:
- Significant savings in testing costs if the simpler electrolytic loading can be validated as a conservative substitute
- Reduction in qualification times and costs
