A unique coating strategy composed of dual-purpose coating is developed as a potential solution for hydrogen embrittlement prevention in metals. This is achieved by extreme high-speed laser application (EHLA) which can introduce thin layers of mechanically sound metallic coating on metal substrates without inducing fusion zones. The coating strategy consists of a top coat and a bond coat on top of the substrate. The top coat acts as a hydrogen permeation barrier aiming to stop hydrogen from diffusing into the substrate. The underlying bond coat has a high hydrogen solubility aiming to capture and retain any remaining hydrogen that might have diffused through the top coat. Metallographic examination such as scanning electron microscopy and electron backscattered diffraction are used to characterize coating integrity. General insights in improving coating quality with processing and materials selections are discussed for future scalable applications.
Hydrogen as a promising alternative energy source that is forecasted to potentially transform future power generation toward new-zero. However, its widespread adoption has proven challenging owing to difficulties around storage, transportation, and usage due to catastrophic failures i.e. hydrogen embrittlement (HE). This is particularly severe for high-strength structural steel that must be designed against fatal fractures; it is also relevant to parts that are not designed for hydrogen exposure due to the prevention of accidental spill or leakage. In order to empower a future hydrogen economy, one of the critical tasks is to ensure hydrogen mobility, i.e. hydrogen storage solution and transportation from one place to another via trucks or pipelines. However, the current infrastructure was not designed with hydrogen in mind which makes efficient transportation challenging and replacement of existing pipelines costly. With the global effort to meet zero-emission initiatives, it is timely to create innovative strategies to combat HE so that the adaption of hydrogen energy can be accelerated, which industry has an estimated global market size of $220b [1].
