In a significant advancement for the construction and aerospace sectors, a recent study published in the Journal of Advanced Joining Processes has shed light on the intricate relationship between process parameters and defect formation in laser powder bed fusion (LPBF) of the nickel-based superalloy IN625 on an IN738LC substrate. This research, led by Amirhossein Riazi from the School of Metallurgy & Materials Engineering at Iran University of Science and Technology, addresses a crucial aspect of additive manufacturing that could reshape repair methodologies for gas turbine components.
Gas turbines are essential in various industries, including energy and aviation, where their reliability is paramount. The degradation of these components is a common issue, and while direct laser deposition (DLD) has been the focus of previous studies due to its repair capabilities, Riazi’s team highlights the superior dimensional accuracy and surface quality offered by LPBF. “Our findings indicate that LPBF not only enhances the repair process but also significantly reduces defects such as pores and cracks,” Riazi explained, emphasizing the potential for improved performance in critical applications.
The research meticulously examined a range of process parameters, including laser power settings from 100 to 200 W and scan speeds varying from 100 mm/s to 2700 mm/s. The team discovered that the concentration of elements at the IN625/IN738 interface plays a pivotal role in crack formation. Riazi noted, “Understanding how elements diffuse from rich to poor regions allows us to predict cracking behavior, which is essential for improving the reliability of repaired components.”
At lower scan speeds, the study found that increasing both speed and power could lead to higher elemental concentration at the interface, with speed promoting accumulation behind the interface and power facilitating homogenization. This nuanced understanding of process parameters could lead to more effective strategies for mitigating defects, ultimately enhancing the durability and performance of gas turbine components.
Moreover, the research delved into the impact of these parameters on microhardness and cell size, revealing that cracks do not form in softer nickel-based matrices where microhardness remains below a critical threshold of 256 HV. This insight could guide manufacturers in selecting appropriate materials and settings to ensure the integrity of repairs.
The implications of this research extend beyond the laboratory. By refining LPBF techniques, the construction sector could see significant reductions in repair costs and downtime for critical machinery. As industries increasingly turn to additive manufacturing for component repair, Riazi’s work could pave the way for more reliable and efficient processes.
For further details on this groundbreaking study, you can visit the School of Metallurgy & Materials Engineering. The findings underscore the importance of ongoing research in additive manufacturing, particularly in understanding the underlying mechanisms that govern defect formation and material properties. As sectors continue to embrace advanced manufacturing techniques, studies like Riazi’s will be instrumental in driving innovation and enhancing operational efficiency.
