The potential use of laser cladded functionally graded materials to mitigate degradation in boiler tube heat exchangers for power plant applications: a review

ABSTRACT

Surface modification is essential to safeguard heat exchangers from premature failure spurred by deterioration mechanisms such as corrosion and wear, which diminish performance. Meanwhile, modifying some substrates with dissimilar materials is challenging due to a mismatch in material properties. Moreover, individual alloy coatings on substrates are usually insufficient in the required material properties, leading to accelerated failure of equipment, especially in power plant industries. This article summarised the knowledge base on functionally graded materials (FGMs) while emphasising how this promising class of novel materials can reduce deterioration. Additionally, laser cladding is established to be a suitable technique for processing FGMs. A particular focus is laid on the laser beam interaction with the FGM and expounding on the processing and material parameters that affect the microstructural properties of FGMs. The development prospects for processing FGMs with superior clad quality characteristics to increase boiler pipes’ service life and performance are also highlighted.

KEYWORDS:

• Corrosion
• heat exchanger
• laser cladding
• optimisation
• process parameters
• functionally graded materials
• wear
• failure

Acknowledgements

The authors would like to express profound gratitude and appreciation to the Education for Laser-based Manufacturing (ELbM) consortium (No. 2019-1973/5 – Project No 614655), funded by the European Union for the award of a scholarship to the first author. The JKUAT and BIUST management is well appreciated for their valuable support in availing essential academic online resources and facilities.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by European Commission: [Grant Number No. 2019-1973/5].