Interface Analysis between Inconel 625 and Cobalt-Chromium Alloy Fabricated by Powder Bed Fusion Using Pulsed Wave Laser

Abstract

A few components used in the aerospace and petrochemical industries serve in corrosive environments at high temperatures. Corrosion-resistant metals or unique processes, such as coating and fusion welding, are required to improve the performance of the parts. We have used laser powder bed fusion (LPBF) technology to deposit a 5 mm thick corrosion-resistant CoCrMo layer on a high-strength IN625 substrate to improve the corrosion resistance of the core parts of a valve. This study found that when the laser volumetric energy density (EV) ≤ 20, the tensile strength increases linearly with the increase in EV, and the slope of the curve is approximately 85°. The larger the slope, the greater the impact of EV on the intensity. When EV > 20, the sample strength reaches the maximum tensile strength. When the EV increases from 0 to 20, the fracture position of the sample shifts from CoCrMo to IN625. When EV ≤ 38, the strain increases linearly with the increase in EV, and the slope of the curve is approximately 67.5°. The sample strain rate reaches the maximum when EV > 38. Therefore, for an optimal sample strength and strain, EV should be greater than 38. This study provides theoretical and technical support for the manufacturing of corrosion-resistant dissimilar metal parts using LPBF technology.

Interface Hardness Analysis of between IN625 and CoCrMo Manufactured by Pulsed Wave Laser Powder Bed Fusion

“…A comprehensive evaluation of sample quality requires considering sample tensile strength. Yao et al’s tensile strength test results for IN625/CoCrMo were incorporated [ 38 ]. It becomes evident that at E v ≤ 20 J/mm 3 , the interface strength is notably low, with fractures occurring on the CoCrMo side.…”

“…Therefore, we used a PW laser to deposit 10 mm-thick CoCrMo on the IN625 substrate to study the effect of different volumetric laser density, E v , on the interface hardness between IN625 and CoCrMo. Additionally, we utilized tensile strength data obtained from Yao et al’s research [ 38 ] to support our investigation. We aimed to recommend optimal E v values that ensure high reliability and durability of multi-metal components by achieving a desired interface hardness while preserving high strength.…”

Mechanical Properties and Interfacial Characterization of Additive-Manufactured CuZrCr/CoCrMo Multi-Metals Fabricated by Powder Bed Fusion Using Pulsed Wave Laser

“…Designing manufacturing strategies [ 14 , 15 , 16 , 17 ], creating interlocked interface structures [ 18 , 19 , 20 , 21 ], conducting heat treatments in post-processing [ 22 , 23 , 24 , 25 ], and introducing transition layers [ 4 , 26 , 27 , 28 ] are the main methods that have been proposed to improve the interface properties in additive-manufactured multi-metals. Up to now, various manufacturing strategies such as process parameter optimization, laser remelting, substrate preheating, and developing functionally graded structures have been proposed to be applied to improve the interface properties.…”