In the heart of Xinjiang, China, researchers are pushing the boundaries of laser cladding technology, with implications that could reverberate through the energy sector. Quanwei Cui, a professor at Xinjiang University’s School of Mechanical Engineering, has led a study that sheds new light on the thermal dynamics of multi-layer laser cladding, a process crucial for enhancing the surface properties of materials used in demanding environments.
Laser cladding is a precision technique that deposits material onto a substrate to improve its resistance to wear, corrosion, and heat. It’s a vital process in the energy sector, where components often face extreme conditions. However, the complexity of multi-layer and multi-pass laser cladding has, until now, been shrouded in mystery. “The thermal accumulation and its influence on the flow field and formation quality of the clad layer have not been fully understood,” Cui explains.
Cui and his team have developed a sophisticated finite element model that integrates heat transfer, fluid flow, and free surface dynamics. This model simulates the multi-layer deposition of IN718 alloy onto a 45 steel substrate, revealing the dynamic evolution of temperature and flow fields under thermal accumulation.
The findings are intriguing. The study shows that interlayer thermal accumulation has a more substantial influence than multi-pass overlapping. As the cladding process progresses, the temperature gradient continuously decreases. Starting at 1.53 × 10^6 K m^−1 after the first pass, it sharply declines during interlayer deposition, ultimately reaching 8.5 × 10^5 K m^−1 by the end of cladding—a total reduction of 44.4%.
The molten pool flow velocity also exhibits a unique behavior, initially increasing from 0.42 m s^−1 to 0.45 m s^−1, then decreasing and stabilizing at 0.37 m s^−1. Moreover, the study highlights the phenomenon of gravity-driven pool inclination due to insufficient edge support, particularly evident in the final pass of each layer.
The model’s reliability is confirmed by the close alignment of simulated pool morphology with experimental cross-sections and a mere 4.42% average error between temperature measurements and simulation results.
So, what does this mean for the energy sector? Understanding and controlling these thermal dynamics can lead to more efficient and precise laser cladding processes. This could result in components with enhanced properties, improved performance, and extended lifespans. As Cui puts it, “This research provides a deeper understanding of the laser cladding process, which can guide the optimization of process parameters and improve the quality of clad layers.”
The study, published in the journal “Materials Research Express” (translated to English as “Materials Research Express”), marks a significant step forward in laser cladding technology. It opens up new possibilities for the energy sector and beyond, promising to shape the future of material surface enhancement. As the world continues to demand more from its materials, research like this is not just interesting—it’s essential.